Cooking For Geeks Part 6

- This soup by itself is very basic. Garnish with whatever else you have on hand that you think might go well, such as garlic croutons and bacon. Or top with a small dab of cream, some toasted walnuts, and dried cranberries to give it a feeling of Thanksgiving. How about a teaspoon of maple syrup, a few thin slices of beef, and some fresh oregano? Chives, sour cream, and cheddar cheese? Why not! Instead of purchasing items to follow a recipe exactly, try using leftover ingredients from other meals to complement the squash soup.

- If you're in a rush, you can "jump-start" the squash by microwaving it first. Peel and quarter the squash, using a spoon to scoop out the seeds. Then, cube it into 12 / 35 cm pieces, drop it into a gla.s.s baking pan that's both oven and microwave safe, and nuke it for four to five minutes to partially heat the ma.s.s. Remove from microwave, coat the squash with olive oil and a light sprinkling of salt, and roast it in a preheated oven until done, about 20 to 30 minutes. If you're not in a rush, you can skip the peeling step entirely: cut the squash in half, scoop out the seeds, add oil and salt, roast it for about an hour (until the flesh is soft), and use a spoon to scoop it out.

[image]To cut thick gourds such as squash and pumpkins, use a large chef's knife and a mallet. First, slice off a thin piece of the gourd so that it lies flat and doesn't roll, then gently tap the knife blade through the gourd.White Bean and Garlic Soup (Winter)In a bowl, soak for several hours or overnight: - 2 cups dry white beans, such as cannelloni beans After soaking overnight, drain the beans, place them in a pot, and fill it with water (try adding a few bay leaves or a sprig of rosemary). Bring to a boil and simmer for at least 15 minutes. Strain out the water and put the beans back in a pot (if using an immersion blender) or in the bowl of a food processor.Add to the pot or bowl with beans and then puree until blended: - 2 cups (500g) chicken or vegetable stock - 1 medium (150g) yellow onion, diced and sauteed - 3 slices (50g) French bread, coated in olive oil and toasted on both sides - head (25g) garlic, peeled, crushed, and sauteed or roasted - Salt and pepper, to taste

Notes.

- Don't skip soaking and boiling the beans. Really. One type of protein present in beans-phytohaemagglutinin-causes extreme intestinal distress. The beans need to be boiled to denature this protein; cooking them in a slow cooker or sous vide setup (see Chapter7 Chapter7) will not denature the protein and actually makes things worse. If you're in a rush, use canned white beans; they'll have already been cooked.

- Variations: try blending some fresh oregano into the soup. Toss some bacon chunks on top or grate on some Parmesan cheese as well. As with many soups, how chunky versus how creamy to blend the soup is a personal preference.

- Make sure to toast the French bread to a nice golden brown. This will add the complex flavors from caramelization and Maillard reactions in the sugars and proteins from the bread. You can pour olive oil onto a flat plate and dip the bread in to coat it.

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If you're not much of a soup person, try making savory sorbets using seasonal ingredients. A summer sorbet with tomatoes and tarragon? Yum. Carrot ice cream? Why not? And for winter, while unusual, bacon ice cream has been enjoyed by diners at Chef Heston Blumenthal's UK-based restaurant The Fat Duck, and taken further with candied bacon bits in a recipe on David Lebovitz's blog (search online for "candied bacon ice cream recipe").

Finally, here are a few tips related to seasonality to keep in mind: - Use fresh herbs whenever possible, because most dried herbs don't have anywhere near the strength of flavor. The volatile oils that are responsible for so much of the aromas in herbs oxidize and break down, meaning that the dry herbs are a pale subst.i.tute. Dried herbs have their place, though; it makes sense to use dried herbs in the dead of winter when annual plants like basil aren't in season. Store dry herbs in a cold, dark place (not above the stove!) to limit the amount of heat and light, which contribute to the breakdown of organic compounds in spices.

- Grind your own spices as much as possible. Fresh-grated nutmeg will be much stronger than preground nutmeg, for the same reasons that many fresh herbs are better than their dried counterparts: the aromatic compounds in a preground spice will have had time to either hydrate or oxidize and disperse, resulting in flavor loss. Most spices also benefit from being bloomed-cooked in oil under moderate but not scorching heat-as a way of releasing their volatile chemicals without breaking them down.

- If you're looking for convenience, commercially frozen vegetables and fruits are actually pretty good. Freezing produce right when it is harvested has a few advantages: nutritional breakdown is halted, and the frozen item is from the peak of the season while the fresh version in your store may have been harvested early or late. Using frozen produce is especially useful if you're cooking for just yourself, because you can pull out a single portion at a time. If you're growing your own food and intend to freeze it, look up online how to use dry ice to pack and quick-freeze the produce; freezing in your home freezer takes too long and leads to mushy veggies.

- When selecting produce at the store, think about when you'll want to use it. For example, if you're buying bananas to eat throughout the week, instead of buying one cl.u.s.ter of mostly green bananas, buy two smaller cl.u.s.ters, one mostly yellow (for sooner) and one mostly green (for later). Picking in-season produce and selecting it so that it will be ripe when you're ready to use it are good ways to guarantee quality.

Organic Versus ConventionalOrganic foods are those grown or raised to USDA National Organic Program (NOP) regulations on farms or ranches certified as following those regulations. Organic produce has restrictions on which pesticides can be used; animals butchered for organic meats are required to be given access to the outdoors and are prohibited from being given antibiotics or growth hormones. Because of these restrictions, the cost of producing organic food is typically higher. are those grown or raised to USDA National Organic Program (NOP) regulations on farms or ranches certified as following those regulations. Organic produce has restrictions on which pesticides can be used; animals butchered for organic meats are required to be given access to the outdoors and are prohibited from being given antibiotics or growth hormones. Because of these restrictions, the cost of producing organic food is typically higher.Conventional foods are those not certified for sale under the label are those not certified for sale under the label organic organic, regardless of whether they are grown to the same standards and regardless of their place of origin. They must still be grown to acceptable USDA/FDA standards, though.When it comes to produce, just because it's organic doesn't mean it's automatically safer, just as software labeled as open source open source isn't necessarily of higher quality than proprietary software. Of course, there are other reasons to buy organic, but if your concern is food safety and pesticides, the benefit of organic isn't necessarily clear-cut: whether exposure to traditional pesticides is always worse for you than exposure to their organic replacements is not yet known. The detectable levels of pesticides in our bodies are well below anything approaching toxic, and as chemists have told me, "it's the dosage that matters." To put some numbers to it, consider what Dr. Belitz et al. wrote in isn't necessarily of higher quality than proprietary software. Of course, there are other reasons to buy organic, but if your concern is food safety and pesticides, the benefit of organic isn't necessarily clear-cut: whether exposure to traditional pesticides is always worse for you than exposure to their organic replacements is not yet known. The detectable levels of pesticides in our bodies are well below anything approaching toxic, and as chemists have told me, "it's the dosage that matters." To put some numbers to it, consider what Dr. Belitz et al. wrote in Food Chemistry Food Chemistry (Springer): "[T]he natural chemicals [in a cup of coffee] that are known carcinogens are about equal to a year's worth of synthetic pesticide residues that are carcinogens." (Springer): "[T]he natural chemicals [in a cup of coffee] that are known carcinogens are about equal to a year's worth of synthetic pesticide residues that are carcinogens."Given the option, farmers would rather not have to spray any type of pesticide on their crops: it costs money, takes time, and increases their exposure to the chemicals. Just keep in mind that if there were an easy answer-say, if organic practices were always better and always cheaper-everyone would be doing it that way.If you do feel going organic is for you but are on a tight budget, here are some general rules of thumb. For fruits, if you're going to eat the skin, buy organic. If you're going to peel them, buying organic appears to offer comparatively little advantage when it comes to exposure to pesticides. For veggies, organic bell pepper, celery, kale, and lettuce test as having lower levels of pesticides than their conventional counterparts. Go organic for dairy, eggs, and meats; for seafood, see the previously mentioned Monterey Bay Aquarium's "Seafood WATCH" program at http://www.seafoodwatch.com.If you're interested in seeing for yourself if organic food tastes different from conventional food, try this side-by-side experiment. Make two versions of a simple pasta dish with sauteed chicken and red and yellow bell peppers, using organic ingredients in one and conventional in the other. How does organic chicken compare to conventional chicken? Can you taste the difference in the bell peppers? For that authentic scientific experience, serve the side-by-side meal to a bunch of friends without revealing which bowl contains the organic version to run a true "taste test." You might find the variance in flavor to be greater-or less-than you expect.[image]Tim Wiechmann's Beet Salad[image]Chef Wiechmann is the chef and owner of T.W. Food in Cambridge, MA. He creates his menus using local organic produce with a cla.s.sic French approach.How you go from planning a dish to putting it on the table?I start with the ingredients-they all have to be in season. I came up with a dish that was made with leftover cheese from the Pyrenees. Black cherries and beets are in season, so how can I dress up a beet salad? In the Pyrenees, they have cherries with sheep's milk cheese. Most of my stuff comes from cultural things, from traveling all over and having a sound grasp on food in Europe. I study what people make from all over-they do this here, they do that there. And these things are done for thousands of years. I try to have a knowledge of these things and then I just look at my own ingredients here, and I draw them together.What is your approach in the kitchen and what thoughts do you have on technology in the kitchen?My menu is actually really difficult. My employees start out with this picture that we just dig out a carrot and boil it. We don't do that. Everything goes through a rigorous, precise set of cooking parameters. With certain preparations, time and temperature are everything. There are things like the water circulator you can use to cook all the meats and fishes perfectly every time. Even for cutting things, we use rulers and metal caramel cutters.Observation is critical, as is getting experience in knowing what looks good. If you're cooking an onion, it changes color over time. There are certain stages where you want to pull it because the bitterness increases as the caramelization increases. Onions in a tall pot will sweat differently than onions in wide pot. In a tall pot, they release their own water and cook evenly because the water doesn't disappear. We have specific pots that are good for certain things-sweat the onions in this pot; don't use that pot-but a new cook will just grab any pot.How do you know if something is going to work?You just try. When you start to play the piano, you don't know where the notes are. You have to have the technique, then you can think about putting the notes together. If I hit this note, then I'll get this sound; if I want onions to be sweet, I'll caramelize them. The technique follows the knowledge. I keep a log of my own recipes and times for each thing. How long to put cherries or apples in a bag and cook in the water circulator, that comes out of experience.My big thing I always say: "Get into it and go for it." Just buy it and try it. Every time you cook something-even if you burn it and it goes in the trash-it's not a failure, it's just: next time I'm not going to burn it.Out of all these criteria that make for a good evening, clearly food is an important one, but what do you think people underestimate?Little things. Maybe they don't know why they don't like something. You know what I mean? "Well, I'm not sure. I just didn't like it." I think very few people know what they like and can identify what they like. That's why I'm pretty good at what I do-I really know what I like. Do you know what you like?I'll have to give it some thought.I don't know what I like in the visual art world. I just haven't spent enough time on it.I can answer that one on the visual art world. Anything that prompts an emotional response. It might not be a positive emotion, but it should stir an emotion or create an experience. Have you seen Ratatouille Ratatouille?Yes.The scene where the camera zooms into the critic's eye and goes back to his childhood as he's eating ratatouille. He has an experience. For me, food needs to touch on emotions.Everybody is geared with that, but I think a lot of people don't know how to identify that. They'll say, "I don't like cauliflower." One really great French chef taught me that you don't have to like it, you just have to make it good. He said, "taste this," to which I said, "I don't like it; I don't want to taste it." He yelled at me. "You're going to be a chef and you can't taste it? You have to taste it." I'll never forget him screaming at me.I think this would apply if you're cooking for friends: keep in mind what your friends are going to enjoy.That's right. My job is to make something that people will enjoy.Roasted Red and Candystripe Beet Salad with Almond Flan, Black Cherry Compote, and Ossau-IratyServes 8; Prep time: 2 hours.Prepare the cherry compote. In a container, measure out and soak overnight: In a container, measure out and soak overnight: - 4 cups (600g) pitted black cherries - 1 cups (340g) sugar - 1 tablespoon (10g) apple pectin - 2 vanilla beans, sliced open lengthwise After soaking overnight, transfer to a pan, add the zest and juice of a lemon, and cook over medium heat for an hour, until the mixture reaches a jam-like consistency. Transfer to a plastic container or jar and cool.Prepare the flan. In a blender, combine: In a blender, combine: - 1 cup (150g) almonds, toasted - 1 teaspoon (5g) almond extract - 6 medium (330g) eggs - 2 cups (480g) heavy cream - Nutmeg, salt, pepper to taste Pour onto a quarter sheet pan (9 13 / 23 cm 33 cm) lined with a Silpat or parchment paper and bake at 300F / 150C until the custard sets, about 45 minutes. Cool on the sheet in refrigerator.Prepare the beets. Preheat oven to 450F / 230C. Create a foil pouch containing: Preheat oven to 450F / 230C. Create a foil pouch containing: - 6 medium (500g) red beets - 6 medium (500g) candystripe beets (also known as chioggia beets) - Salt, olive oil, and pepper to taste Roast until tender, about 45 minutes, depending on the size of the beets. Remove from pouch and peel with a knife. Cut the beets into attractive circles or cubes.To serve. Make a quick salad dressing with oil and vinegar, salt and pepper. Toss the beets and 1 cup / 90g of toasted slivered almonds in the dressing. Make a quick salad dressing with oil and vinegar, salt and pepper. Toss the beets and 1 cup / 90g of toasted slivered almonds in the dressing.Arrange the beets and almonds on large plates. Place a nice slice of flan somewhere among them and drop a few scoops of the cherry compote in various places.Using a vegetable peeler, shave into long strands (about 4 / 10 cm): - pound (225g) Ossau-Iraty (a medium-soft cheese from the French Pyrenees, creamy and complex) Decorate the salad with the shaved Ossau-Iraty.RECIPE USED BY PERMISSION OF TIM WIECHMANNGenetically Modified FoodsRegardless of your feelings about or definition of GMO (genetically modified organism) foods, the topic is an intensely charged political and social minefield. Fear of the unknown has a long record of helping to guarantee the survival of our species, so avoiding things until they've established a history of being safe does certainly seem prudent. But this view doesn't consider the potential harms that a GMO-based food might be able to avert.What if a strain of rice could be produced that was more resilient in the face of floods and droughts? Such a strain of rice would increase crop yields for families in impoverished countries, and the need is only going to increase. The United Nations' food agency expects that worldwide food production will need to increase by 70% between 2010 and 2050. Or how about strains of rice or corn that need fewer pesticides to remain viable crops? Worldwide, some 300,000 deaths a year are attributed to pesticide poisoning.Then there's "Golden Rice," a golden-yellow rice that has been genetically modified to produce increased amounts of beta-carotene as a way of addressing Vitamin A deficiencies that impact the extremely poor in some nations. Everyone agrees that Vitamin A deficiencies are a serious problem: an estimated 1 to 2 million million children die every year due to Vitamin A deficiency, according to a 1992 World Health Organization report. Still, Golden Rice has not yet been approved for human consumption; organizations like Greenpeace have opposed it, saying that it's an unproven solution and that other, better solutions exist. children die every year due to Vitamin A deficiency, according to a 1992 World Health Organization report. Still, Golden Rice has not yet been approved for human consumption; organizations like Greenpeace have opposed it, saying that it's an unproven solution and that other, better solutions exist.More personally, would you accept genetically engineered cows guaranteed to be free of prions, which cause Bovine spongiform encephalopathy (a.k.a. "mad cow disease")? Or how about a GMO banana that was able to withstand the fungus Fusarium oxysporum Fusarium oxysporum that threatens to wipe out the banana as we know it? Related to GMO foods, would you accept irradiated chicken if it was guaranteed to be free of salmonella? that threatens to wipe out the banana as we know it? Related to GMO foods, would you accept irradiated chicken if it was guaranteed to be free of salmonella?This isn't to suggest that you should seek out seek out GMO-based foods; but at the very least you should recognize that there are very real trade-offs. Hundreds of Americans die annually from salmonellosis, and while those deaths can be avoided with proper cooking, perhaps we as a society shouldn't blindly fear technologies that could prevent those deaths just because they're unfamiliar. GMO-based foods; but at the very least you should recognize that there are very real trade-offs. Hundreds of Americans die annually from salmonellosis, and while those deaths can be avoided with proper cooking, perhaps we as a society shouldn't blindly fear technologies that could prevent those deaths just because they're unfamiliar.Sure, it might be reasonable to fear corporate overlording corporate overlording-the idea that our food chain might become reliant upon a corporation with a patent on the very food we need to survive-but this is a separate issue from GMO food itself. Another argument against GMO foods claims that the money spent on GMO research would be better spent on other areas of agricultural technology; but again, this is a separate issue from whether genetically modifying food itself should be done.I personally do not enjoy burgers served by fast food chains, but I recognize that they are able to feed literally millions of American families every day. Around the world, advances in technology have increased crop yields and improved the quality of life for many, although there are still many in starving conditions. What happens to those families who are just barely making ends meet when the prices of food exceed what they can afford?Non-GMO foods are not inherently more expensive, but the economics to date have tended to make the price of GMO foods cheaper. The quick-serve industry is not saying "we want GMO foods"; they're simply buying what's most economical, because in a price-sensitive market, the chains need to keep prices down to remain in business.For a glimpse into the interconnectedness of our food system, search online for Louise Fresco's touching TED talk, "On Feeding the Whole World" ( (http://www.ted.com/talks/louise_fresco_on_feeding_the_whole_world.html).[image]

a.n.a.lytical Method There have been a number of attempts over the years to devise a scientific model for predicting which flavors will work well together. While not particularly well suited for day-to-day cooking, these types of approaches do have a place in helping create new combinations of flavors and they are used by the food industry and some high-end chefs.

NoteA disclaimer: picking pleasing flavors-or at least ones that invoke an emotional response or trigger a memory-is somewhere between an art and a science, so no scientific equation can capture the entire picture. Still, understanding how such a "flavor compatibility algorithm" would work can provide you with a way of organizing your thoughts on food, and for geeks, it's fun to see how far one can take these sorts of things. If you really want to geek out and need a food project to work on, an open source version of this concept would be fun.

To start, we need a model of how to describe individual flavors, before considering how to combine them. Odors can be categorized in a few ways, most commonly either chemically or descriptively.

Chemical taxonomies cla.s.sify compounds by their odors. Such a taxonomy is essentially a database of chemicals that each map to distinct flavor sensations. For example, Flavornet (http://www.flavornet.org (http://www.flavornet.org), created by two researchers at Cornell (Acree and Arn), describes some 700+ chemical odorants detectable by the human nose. Listing compounds such as citronellyl valerate citronellyl valerate (smells like honey or rose; used in drinks, candies, and ice cream), the database is useful for generating certain flavors artificially, but not so useful outside of laboratory kitchens. (smells like honey or rose; used in drinks, candies, and ice cream), the database is useful for generating certain flavors artificially, but not so useful outside of laboratory kitchens.

Descriptive taxonomies apply labels to odors as a way of cla.s.sifying and grouping foods. For example, both lemon and orange are generally cla.s.sified as "fruity/citrus." Lacking the precision of a chemical taxonomy (the compound is either present or it isn't), descriptive taxonomies suffer from the subjectivity of human judgment. Most of us would agree that a lemon smells "fruity/citrus," but how much does a food like chocolate smell of the odors in celery? Not much, but certainly more than chocolate smells of fish.

NoteThe simplest descriptive taxonomy, from the 1950s by J. E. Amoore, proposes just seven primary odors: camphoric (like mothb.a.l.l.s), ethereal (like cleaning fluid), floral (like roses), musky (like aftershave), pepperminty, pungent (like acetic acid in vinegar), and putrid (like rotten eggs).

One modern descriptive taxonomy can be found in the American Society for Testing and Materials' Atlas of Odor Character Profiles DS61 Atlas of Odor Character Profiles DS61, by Andrew Dravnieks. While you might not necessarily think of all of the terms included as pleasant, it's certainly a diverse set, which is useful in thinking about smells. With 146 terms, Dravnieks's list also provides enough granularity to begin to form a meaningful model for food flavors.

Common Sweet, fragrant, perfumy, floral, cologne, aromatic, musky, incense, bitter, stale, sweaty, light, heavy, cool/cooling, warm Foul Fermented/rotten fruit, sickening, rancid, putrid/foul/decayed, dead animal, mouse-like General foods b.u.t.tery (fresh), caramel, chocolate, mola.s.ses, honey, peanut b.u.t.ter, soupy, beer, cheesy, eggs (fresh), raisins, popcorn, fried chicken, bakery/fresh bread, coffee Meats Meat seasoning, animal, fish, kippery/smoked fish, blood/raw meat, meat/cooked good, oily/fatty Fruits Cherry/berry, strawberry, peach, pear, pineapple, grapefruit, grape juice, apple, cantaloupe, orange, lemon, banana, coconut, fruity/citrus, fruity/other Vegetable Fresh vegetables, garlic/onion, mushroom, raw cuc.u.mber, raw potato, bean, green pepper, sauerkraut, celery, cooked vegetables Spices Almond, cinnamon, vanilla, anise/licorice, clove, maple syrup, dill, caraway, minty/ peppermint, nut/walnut, eucalyptus, malt, yeast, black pepper, tea leaves, spicy Body Dirty linen, sour milk, sewer, fecal/manure, urine, cat urine, seminal/like sperm Materials Dry/powdery, chalky, cork, cardboard, wet paper, wet wool/wet dog, rubbery/ new, tar, leather, rope, metallic, burnt/smoky, burnt paper, burnt candle, burnt rubber, burnt milk, creosote, sooty, fresh tobacco smoke, stale tobacco smoke Chemicals Sharp/pungent/acid, sour/acid/vinegar, ammonia, camphor, gasoline/solvent, alcohol, kerosene, household gas, chemical, turpentine/pine oil, varnish, paint, sulphidic, soapy, medicinal, disinfectant/carbolic, ether/anaesthetic, cleaning fluid/carbona, mothb.a.l.l.s, nail polish remover Outdoors Hay, grainy, herbal/cut gra.s.s, crushed weed, crushed gra.s.s, woody/resinous, bark/ birch, musty/earthy, moldy, cedarwood, oakwood/cognac, rose, geranium leaves, violets, lavender, laurel leaves REPRINTED, WITH PERMISSION, FROM DS61 ATLAS OF ODOR CHARACTER PROFILES, COPYRIGHT ASTM INTERNATIONAL, 100 BARR HARBOR DRIVE, WEST CONSHOHOCKEN, PA, 19428.

Dravnieks's 146 odor terms, broken down into main categories, provide a good basis for thinking about odors. If you're heading out on a date and want to impress, this list is a pretty good starting point for describing wines!NoteAnother adjective cla.s.sification system, Allured's Perfumer's Compendium Perfumer's Compendium, is used by the perfume industry, the fine folks responsible for the smells of products from laundry detergent to toothpaste. Think that new car smell is accidental? Trained employees smell the materials that go into the interior of a new car to make sure that it smells just right. (To quote The Matrix The Matrix: "You think that's air you're breathing now?") Allured's taxonomy uses more descriptive and narrow scents-familiar items such as banana, peach, and pear-but also specific items like hyacinth, patchouli, and muguet (lily of the valley), making it less useful to the layperson.

Let's start by defining a flavor profile as the weighted scores of a collection of terms in a cla.s.sification system, such as Dravnieks's 146 odor terms. For every term, imagine taking an item of food-say, a pear-and scoring it on a scale from 1 to 5, where a score of 1 indicates "doesn't smell like it at all" and 5 is "the very definition of the word!" Given a pear, how much does it smell like a "heavy" odor? 1. Fruity? Maybe a 3? Fragrant? Say it's a ripe pear, so 4.

The scoring is not asking if it is a compatible smell, just if the odor label describes the smell. Are the odors you sense in a pear (are the chemoreceptors that fire off in your nose) the same as when you smell other things that are considered fragrant? Given the weights of all of these odor descriptions for a pear, you can plot a graph (almost like a histogram) that you can then compare to similar graphs for other foods.

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Some of Dravnieks's odor terms a.s.sociated with banana and pear, as scored by a few thousand Internet voters (taller bars indicate a larger degree of agreement between food and odor). These voters were not trained or verified to be familiar with the definitions of those odors; for these reasons, this graph should be treated as a conceptual demonstration only.

Given such a graph for each individual ingredient in a recipe, you can imagine a combined graph that describes the overall profile of a dish, showing all the "frequencies" present in the smells of each ingredient. Think of it like the various instruments that contribute to a piece of music: each has its own set of frequencies, and the combination of all the instruments makes up the overall song's frequency distribution. When in tune, the frequencies line up and balance one another; when out of tune, the combination of sounds can be jarringly dissonant, even if each sounds fine individually. Of course, this music a.n.a.logy isn't a perfect fit for thinking about flavors: chemical changes brought about by cooking or by reactions between foods change the histogram, and the music a.n.a.logy doesn't cover other variables in foods, such as texture, weight, or mouth-feel.

Many chefs-often pros, but also non-pros who've been cooking for years-can imagine flavor combinations in their heads, doing something similar to this process mentally. Just as a composer imagines each voice and track in a piece of music, an experienced cook imagines the profile of the entire dish. Good cooks think about which notes are missing or are too soft and figure out what ingredients can be added to bring up those values.

What about achieving entirely new pairings, combinations that have no precedence in tradition? This same concept of matching up foods by their flavors can be done via the chemical taxonomy method, given enough time. The high end of the luxury restaurant industry spends an inordinate amount of time working on new flavor combinations, often with upward of two years spent working on a concept before it's presented. Chef Heston Blumenthal of The Fat Duck (UK) maintains three distinct kitchens, one of which is devoted to laboratory work and is staffed by individuals holding both masters-level degrees in hard sciences like physics or chemistry and and degrees from first-tier culinary inst.i.tutions such as degrees from first-tier culinary inst.i.tutions such as Le Cordon Bleu Le Cordon Bleu. Here is a partial list of pairings Chef Blumenthal has used: strawberry and coriander, snails and beetroot, chocolate and pink peppercorn, carrot and violet, pineapple and certain types of blue cheese, banana and parsley, harissa and dried apricot. Give them a try!

In addition to conducting their own private research, high-end chefs interested in creating new flavor combinations sometimes work with researchers at universities. Both Flavornet (http://www.flavornet.org) and FoodPairing (http://www.foodpairing.be) include such research in their sites. If you're interested in exploring some of the chemical commonalities between ingredients, look at FoodPairing, which uses a chemical flavor database in order to suggest what ingredients to try together. (FoodPairing claims to be used by Chefs Heston Blumenthal and Ferran Adria.) [image]

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Food Pairing diagrams for chocolate and chicken. Their database is based on chemical a.n.a.lysis, and it gives suggestions based on both chemical similarity and chemicals known to be complementary.

GRAPHS USED BY PERMISSION OF BERNARD LAHOUSSE.

The a.n.a.lytical approach tends to be very abstract. There's little here that helps one select what ingredients to toss into a bowl together to make dinner. For this reason, these sorts of tools have yet to become particularly successful. This technique doesn't generate recipes. While a set of odors might go together from an aromatic perspective, there are other variables in cooking that prevent mixing and matching various ingredients indiscriminately. For example, one ingredient might require cooking, while another might break down in high heat.

You can work around these constraints by separating the two ingredients into different components that are prepared separately and combined on the plate-say, a meat with a sauce. Or try using cooking methods that are, in essence, about conveying the perfume in food. Soups, ice creams, even souffles: all are methods of transporting the flavors and aromas of ingredients without carrying the texture or volume of the original ingredient. A number of more recent, novel flavor pairings have used this solution. At the very least, you might find these types of tools a fun source of inspiration to try new things. Go experiment!

Harold McGee on Solving Food Mysteries[image]PHOTO OF HAROLD MCGEE USED BY PERMISSION OF KARL PETZKEHarold McGee writes about the science of food and cooking. He is the author of On Food and Cooking On Food and Cooking (Scribner), described by Alton Brown as "the Rosetta stone of the culinary world." He also writes a column, The Curious Cook, for the (Scribner), described by Alton Brown as "the Rosetta stone of the culinary world." He also writes a column, The Curious Cook, for the New York Times. New York Times. His website is at His website is at http://www.curiouscook.com.How do you go about answering a food mystery?It depends on the nature of the mystery. It can start with and mainly involve experiments in the kitchen, doing a particular process several different ways, changing one thing at a time, and seeing what the effect is. Or it can mean going to the food science or technical literature and hunting for information that might be relevant.A recent example of the latter would be this column I wrote for the New York Times New York Times about keeping berries and fruits longer than normal. I had been going to the farmers' market and getting way too much fruit. It looked and tasted so good, but I couldn't eat it all, and after a day, it would begin to mold, sometimes even in the refrigerator. I thought there might be a way to deal with this. So I drove up to UC Davis and used their online databases to search the literature for methods of controlling mold growth on produce. about keeping berries and fruits longer than normal. I had been going to the farmers' market and getting way too much fruit. It looked and tasted so good, but I couldn't eat it all, and after a day, it would begin to mold, sometimes even in the refrigerator. I thought there might be a way to deal with this. So I drove up to UC Davis and used their online databases to search the literature for methods of controlling mold growth on produce.I discovered that back in the 1970s some guys at one of the ARS [USDA Agricultural Research Service] stations here in California came up with a mild heat treatment that didn't damage the fruit but did slow down substantially the growth of mold on the outside. I came back and gave it a try, and it worked. I didn't have the knowledge or the tools to deal with it without doing some library research. I put it to the test because it's one thing to read about something in the literature and another thing to make sure that it actually plays out that way in somebody's kitchen.Why not do this kind of literature search online? Is there something that UC Davis or an inst.i.tution like that is able to provide researchers that they can't get directly online back home in front of their computers?There are wonderful resources that are available at both university and public libraries that an individual just can't afford to subscribe to. In inst.i.tutions with a food science department, there are resources on the shelf that you would never know about without going and looking, and I enjoy doing that, not necessarily to answer the question "What do people know today about X?" but more "How have people dealt with X over the centuries?"Centuries? Can you give me an example of something from that kind of historical research?Tomato leaves are not toxic the way people thought they were. In fact, they're probably beneficial to eat because they bind to cholesterol and prevent us from absorbing it. The question arose: "How did we get this idea that they're toxic if they're not?"I delved back as far as I could in some pretty obscure literature to try to figure that out, and that included going up to UC Davis and taking a look at a couple of books from the 17th and 18th centuries on Dutch ethnography of the Pacific. I tracked down a reference to people eating tomato leaves on an island in the Indonesian Archipelago in the 17th century. This would have been shortly after tomatoes had been introduced there because they are not native to that part of the world. That fleshes out the story of how this plant found its way around the world, how it developed a reputation, and the kinds of aesthetic judgments that people made about it.In Europe, people didn't eat the leaves because they thought they stank. In Central and South America, where tomatoes came from, the leaves weren't much eaten, which I still don't understand. Just pulling all of these bits together to me is part of the pleasure of understanding and appreciating the food that I sit down and eat at my table today. There is this tremendous depth of history and complexity that, if you delve into it, can make it even more pleasurable to eat these things.One of the things I like best about the job I have is not so much the writing; it's the exploring, it's tracking down these books and reading this paragraph about people on this island centuries ago doing this with the leaves, then coming home and trying to get some sense of what that tasted like using leaves from my own backyard and the equivalent of the preserved fish that they were probably using back then to season them.I imagine that our understanding about food is getting more refined, and we're correcting a lot of previous misconceptions. What do you hope future research will spend time working on?If I could name one area that I wish people with the equipment, expertise, and resources would pay more attention to and work harder on, it is flavor and the influence of different cooking methods on the ultimate experience of particular preparations. There are so many interesting questions about different ways of doing the same thing where, at the moment, basically you have your own personal experience and the experience of other people but no good, objective yardstick.What are the real differences? Are we experiencing the same set of compounds differently because we have different sensory systems, or do, in fact, different techniques produce different sets of compounds where you happen to prefer this and I happen to prefer that? An example would be making stocks. There are some people who are real partisans of doing stocks in pressure cookers and others who think that the long, slow, barely-at-a-simmer method gives you a superior result. I've done both, and I like both, but they are different. I'm not sure I can really explain how they are different, so I would love to know what's going on there.What does the home cook need to understand about what they're doing in the kitchen?A scale and a good thermometer are absolutely essential if you're going to try to understand things and do experiments carefully enough to draw real conclusions. You need to be able to measure, and temperature and weight are the main variables.Is there something that really surprised you in the kitchen?I suppose the one moment in my life that really confounded my expectation was the copper bowl versus gla.s.s bowl for beating egg whites. I was reading Julia Child while I was writing the book [On Food and Cooking] the first time in the late 1970s. She said that you should whip egg whites in a copper bowl because it acidifies the whites and gives you a better foam for meringue and souffles, but the chemistry was wrong. Copper doesn't change the pH of solutions, so I thought that since the explanation was wrong, there probably was nothing to the claim either.Then a couple of years later, when it came time to get ready for publication, I was looking at old graphic sources for ill.u.s.trations for the book. I looked at a French encyclopedia from the 17th century that had a lot of professions ill.u.s.trated. One of them was a pastry kitchen. In the engraving, there was a boy beating egg whites, and it said that the boy was beating egg whites in a copper bowl to make biscuits. It specified a copper bowl, and it looked exactly like today's copper bowls: it was hemispherical and had a ring for hanging. I thought if a French book from 200 years ago is saying the same thing that Julia Child said, then maybe I should give it a try.I tried a gla.s.s bowl and a copper bowl side by side, so I could look at them and taste them, and the difference was huge. It took twice as long to make a foam in the copper bowl; the color was different, the texture was different, the stability was different. That was a very important moment for me. You may know that somebody else doesn't know the chemistry, but they probably know a lot more about cooking than you do. That certainly got me to realize that I really did have to check everything I could.A French chef told me a story. He'd made a million meringues in his life, and one day he was in the middle of whipping the egg whites in a machine. The phone rang-there was some kind of emergency and he had to go away for 15 or 20 minutes-so he just left the machine running. He came back to the best whipped egg whites he'd ever seen in his life. His conclusion from that was, in French, "Je sais, je sais que je sais jamais." It sounds a lot better in French than it does in English, but the English is, "I know, I know that I never know."Thanks to that experience with the copper bowl, that's been my motto as well. No matter how crazy an idea sounds or how much I distrust my own senses when I do something, and it somehow seems inexplicably different from what it should be, I know that I'm never going to understand everything completely, and there's probably a lot more to learn about whatever it is that's going on.

Chapter4.Time and Temperature: Cooking's Primary Variables EVER SINCE CAVEMEN FIRST SET UP CAMPFIRES AND STARTED ROASTING THEIR KILL, MANKIND HAS ENJOYED A WHOLE NEW SET OF FLAVORS IN FOOD. Cooking is the application of heat to ingredients to transform them via chemical and physical reactions that improve flavor, reduce chances of foodborne illness, and increase nutritional value. Cooking is the application of heat to ingredients to transform them via chemical and physical reactions that improve flavor, reduce chances of foodborne illness, and increase nutritional value.

From a culinary perspective, the more interesting and enjoyable changes are brought about when compounds in food undergo the following chemical reactions: - Protein denaturation - The native native form of a protein is the three-dimensional shape (conformation) a.s.sumed by the protein that is required for normal functioning. If this structure is disrupted (typically by heat or acid), the protein is said to be form of a protein is the three-dimensional shape (conformation) a.s.sumed by the protein that is required for normal functioning. If this structure is disrupted (typically by heat or acid), the protein is said to be denatured. denatured. Changes in the shapes of proteins also alter their taste and texture. Changes in the shapes of proteins also alter their taste and texture.

- Different proteins denature at different temperatures; most proteins in food denature in the range of 120160F / 4971C. Egg whites, for example, begin to denature at 141F / 61C and turn white because the shape of the denatured protein is no longer transparent to visible light. In meat, the protein myosin myosin begins to denature around 122F / 50C; another protein, begins to denature around 122F / 50C; another protein, actin actin, begins to denature around 150F / 65.5C. Most people prefer meat cooked such that myosin is denatured while keeping the actin native.[image]

- Maillard reaction - A Maillard reaction is a browning reaction that gives foods an aromatic and mouth-watering aroma. Usually triggered by heat, this occurs when an amino acid and certain types of sugars break down and then recombine into hundreds of different types of compounds. The exact byproducts and resulting smells depend upon the amino acids present in the food being cooked, but as an example, imagine the rich smell of the crispy skin on a roasted chicken.

- For culinary purposes, the reaction generally becomes noticeable around 310F / 154C, although the reaction rate depends on pH, chemical reagents in the food, and amount of time at any given temperature. Many meats are roasted at or above 325F / 160C-at temperatures lower than this, the Maillard reaction hardly occurs.

- Caramelization - Caramelization is the result of the breakdown of sugars, which, like the Maillard reaction, generates hundreds of compounds that smell delicious. Pure sucrose (the type of sugar in granulated sugar) caramelizes at between 320400F / 160204C, with only the middle range of 356370F / 180188C generating rich flavors.

- In baking, those goods that are baked at 375F / 190 C generally have a noticeably browned exterior, while those baked at or below 350F / 175C remain lighter-colored.

"Great," you're probably thinking, "but how does knowing any of this actually help me cook?"

You can tell when something is done cooking by understanding what reactions you want to trigger and then detecting when those reactions have occurred. Cooking a steak? Check the internal temperature with a thermometer; once it's reached 140F / 60C, the myosin proteins will have begun to denature. Baking crispy chocolate chip cookies at 375F / 190C? Open your eyes and keep your nose online; the cookies will be just about done when they begin to turn brown and you're able to smell the caramelization occurring. Really, it's that simple. Foods are "done" when they achieve a certain state, once they have undergone the desired chemical reactions. As soon as the reactions have occurred, pop the food out; it's done cooking.

NoteA small but critical detail: as we'll discuss elsewhere, proteins don't simultaneously denature at a given temperature. Denaturation is a function of duration of exposure at a given temperature. And there are many different types of proteins in different foods, each with its own temperature/time response rate.

Smell, touch, sight, sound, taste: learn to use all of your senses in cooking. Meat that has been cooked until it is medium rare-a point at which myosin has denatured and actin has yet to denature-will feel firmer and also visibly shrink. The bubbling sound of a sauce that's being boiled and reduced will sound different once the water is mostly evaporated, as bubbles pus.h.i.+ng up through the thicker liquid will have a different sound. Bread crust that has reached the temperatures at which Maillard reactions and caramelization occur will smell wonderful, and you'll see the color s.h.i.+ft toward golden brown. By extension, this also means that the crust of the bread must reach a temperature of 310F / 155C before it begins to turn brown, which you can verify using an IR thermometer. (Bread flour has both proteins and sugars, so both caramelization and Maillard reactions occur during baking.) This chapter shows you when and how these changes occur so that you can become comfortable saying, "It's done!" We'll start by looking at the differences between the common sources of heat in cooking and how differences in the type of heat and temperatures impact cooking. Since one of the main reasons for cooking is reducing the chances of foodborne illness, we'll also discuss the key issues in food safety, including a look at how to manage bacterial contamination and parasites, along with some example recipes to demonstrate the principles behind food safety. The remainder of the chapter will then examine a number of key temperature points, starting with the coldest and ending with the hottest, discussing the importance of each temperature point and giving example recipes to ill.u.s.trate the reactions that occur at each of these temperatures.

As with most recipes in this book, the recipes here are components components, not necessarily entire dishes or meals unto themselves. Create your own combinations as you like! It's usually easier to take each of the components in a dish and cook them separately: veggies in one pan, meats or proteins in another, and starches in a third. This allows you to isolate the variables for each component, then combine them at the end. Eggplant Parmesan might be your favorite dish, but if you're new to cooking, it's probably not the best place to start to learn about the reactions taking place.

Finally, cooking and baking share an axiom with coding and product development: it's done when it's done-not when the timer goes off. One of the best tips I can offer for improving your skills in the kitchen is to "calibrate" yourself: take a guess if something is done and then check, taking note of what your senses, especially smell and sight, notice in the process.

NoteTimers are great guides for reminding you to check on a dish and a good safety net in case you're like me and absentmindedly wander off occasionally. But timers are only a proxy for monitoring the underlying reactions. Given a fillet of fish that is done when its core temperature reaches 140F / 60C-which might take about 10 minutes-the primary variable is temperature, not time. If the fish is slow to heat up, regardless of the timer going off at the 10-minute mark, it won't be done yet. Not to knock timers entirely: they're a great tool, especially in baking, where the variables are much more controlled and thus the time needed to cook can be more accurately prescribed. But don't be a slave to the timer.

Cooked = Time * Temperature Since the primary chemical reactions in cooking are triggered by heat, let's take a look at a chart of the temperatures at which the reactions we've just described begin to occur, along with the temperatures that we commonly use for applying heat to food: [image]

Temperatures of common reactions in food (top portion) and heat sources (bottom portion).

There are a few "big picture" things to notice about these common temperatures in cooking. For one, notice that browning reactions (Maillard reactions and caramelization) occur well above the boiling point of water. If you're cooking something by boiling it in a pot of water or stewing it in liquid, it's impossible for high-heat reactions to occur, because the temperature can't go much above 216F / 102C, the boiling point of moderately salted water. If you're cooking a stew, such as the simple beef stew recipe in Chapter2 Chapter2 ( (Simple Beef Stew), sear the meats and caramelize the onions separately before adding them to the stew. This way, you'll get the rich, complex flavors generated by these browning reactions into the dish. If you were to stew just the uncooked items, you'd never get these high-heat reactions.

Another neat thing to notice in the temperature graph is the fact that proteins denature in relatively narrow temperature ranges. When we cook, we're adding heat to the food specifically to trigger these chemical and physical reactions. It's not so much about the temperature of the oven, grill, or whatever environment you're cooking in, but the temperature of the item of food itself.

Which brings us to our first major aha! aha! moment: the most important variable in cooking is the temperature of the food itself, not the temperature of the environment in which it's being cooked. When grilling a steak, the temperature of the grill will determine how long it takes the steak to come up to temperature, but at the end of the day, what you really want to control is the final temperature of the steak, to trigger the needed chemical reactions. For that steak to be cooked to at least medium rare, you need to heat the meat such that the meat itself is at a temperature of around 135F / 57C. moment: the most important variable in cooking is the temperature of the food itself, not the temperature of the environment in which it's being cooked. When grilling a steak, the temperature of the grill will determine how long it takes the steak to come up to temperature, but at the end of the day, what you really want to control is the final temperature of the steak, to trigger the needed chemical reactions. For that steak to be cooked to at least medium rare, you need to heat the meat such that the meat itself is at a temperature of around 135F / 57C.

Denaturing ProteinsWhat's all this talk about "denaturing" proteins? It's all about structure.Denaturing refers to a change in the shape of a molecule ( refers to a change in the shape of a molecule (molecular conformation). Proteins are built of a large number of amino acids linked together and "pushed" into a certain shape upon creation. Since the function of a protein is related to its shape, changing the shape changes the protein's ability to function, usually rendering it useless to the organism.Think of a protein as a bit like the power cable between a laptop and an outlet: while it has a particular primary structure (the cord and wires inside it), the cord itself invariably gets all tangled up and twisted into some secondary structure. (If it's anything like mine, it spontaneously "retangles" itself regardless of attempts to straighten it out, but proteins don't actually do this.)On the molecular level, the cable is the protein structure, and the tangles in the cable are secondary bonds between various atoms in the structure. Atoms can be relocated to different bonding spots, changing the overall shape of the molecule, but not actually changing the chemical composition. With its new shape, however, the molecule isn't always able to perform its original function. It might no longer fit into places that it used to be able to go, or given the new conformation, other molecules might be able to form new bonds with the molecule and prevent it from functioning as it used to.[image]

Heat Transfer and Doneness The idea that you can just cook a steak any old way until it reaches 135F / 57C sounds too easy, so surely there must be a catch. There are a few.

For one, how you get the heat into a piece of food matters. A lot. Clearly the center of the steak will hit 135F / 57C faster when placed on a 650F / 343C grill than in a 375F / 190C oven. The hotter the environment, the faster the ma.s.s will heat up, thus the rule of thumb: "cooking = time * temperature." Consider the internal temperatures of steak cooked two ways, grilled and oven-roasted: [image]

Schematic diagram of temperature curves for two imaginary steaks, one placed in an oven and a second placed on a grill.

Cooking a steak on a grill takes less time than in an oven, because energy is transferred faster in the hotter environment of the grill. Note that the error tolerance of when to pull the meat off the grill is smaller than pulling the meat from the oven, because the slope of the curve is steeper. That is, if t t1 is the ideal time at which to pull the steak, leaving it for is the ideal time at which to pull the steak, leaving it for t t1+2 minutes will allow the temperature of the grilled steak to overshoot much more than one cooked in the oven.

This is an oversimplification, of course: the graph shows only the temperature at the center of the ma.s.s, leaving out the "slight" detail of the temperature of the rest of the meat. (It also doesn't consider things like rate of heat transfer inside the food, water in the meat boiling off, or points where proteins in the meat undergo phase changes and absorb energy without a change in temperature.) Another thing to realize about heat transfer is that it's not linear. Cooking at a higher temperature is not not like stepping on the pedal to get to the office faster, where going twice as fast will get you there in half the time. Sure, a hotter cooking environment like a grill will heat up the outer portions of the steak faster than a relatively cooler environment like an oven. But the hotter environment will continue to heat the outer portions of the steak before the center is done, resulting in an overcooked outer portion compared to the same size steak cooked in an oven to the same level of internal doneness. like stepping on the pedal to get to the office faster, where going twice as fast will get you there in half the time. Sure, a hotter cooking environment like a grill will heat up the outer portions of the steak faster than a relatively cooler environment like an oven. But the hotter environment will continue to heat the outer portions of the steak before the center is done, resulting in an overcooked outer portion compared to the same size steak cooked in an oven to the same level of internal doneness.

What's the appeal of cooking on a hot grill, then? For the right cut of meat, you can keep a larger portion of the center below the point at which proteins become tough and dry (around 170F / 77C) while getting the outer portion up above 310F / 154C, allowing for large amounts of Maillard reactions to occur. That is, the grill helps give the outside of the steak a nice brown color and all the wonderful smells that are the hallmark of grilling-aromas that are the result of Maillard reactions. The outside portion of grilled meat will also have more byproducts from the Maillard reactions, resulting in a richer flavor.

Juggling time and temperature is a balancing act between achieving some reactions in some portions of the meat and other reactions in other parts of the meat. If you're like me, your ideal piece of red meat is cooked so that the outer crust is over 310F / 155C and the rest of the meat is just over 135F / 57C, with as little of the meat between the crust and the center as possible being above 135F / 57C. The modern technique of sous vide cooking can be used to achieve this effect; we'll cover this in Chapter7 Chapter7.

"Cooking = time * temperature"This has to be one of the hand-waviest formulas ever. I hereby apologize. To make up for it, here's an actual mathematical model for temperature change as a function of heat being applied. Remember to cook until medium-rare...[image]SOURCE: M. A. BELYAEVA (2003), "CHANGE OF MEAT PROTEINS DURING THERMAL TREATMENT," CHEMISTRY OF NATURAL COMPOUNDS CHEMISTRY OF NATURAL COMPOUNDS 39 (4) 39 (4) Temperature gradients This balancing act-getting the center cooked while not overcooking the outside-has to do with the rate at which heat energy is transferred to the core of a food. Since cooking applies heat to foods from the outside in, the outer portions will warm up faster, and because we want to make sure the entire food is at least above a minimum temperature, the outside will technically be overcooked by the time the center gets there. This difference in temperature from the center to outer edges of the food is referred to as a temperature gradient temperature gradient.

NoteChoose the method of cooking to match the properties of the food you are cooking. Smaller items-skirt steak, fish fillets, hamburgers-work well at high heats. Larger items-roasts, whole birds, meatloaf-do better at moderate temperatures.

[image]

Lower heat sources bring up the temperature of the meat more uniformly than hotter heat sources.

All parts of our example steak are not going to to reach temperature simultaneously. Because grill environments are hotter than ovens, the temperature delta between the environment and the food is larger, so foods cooked on the grill will heat up more quickly and have a steeper temperature gradient.

Carryover Carryover in cooking refers to the phenomenon of continued cooking once the food is removed from the source of heat. While this seems to violate a whole bunch of laws of thermodynamics, it's actually straightforward: the outer portion of the just-cooked food is hotter than the center portion, so the outer portion will transfer some of its heat into the center. You can think of it like pouring hot fudge sauce on top of ice cream: even though there's no external heat being added to the system, the ice cream melts because the hot fudge raises its temperature. in cooking refers to the phenomenon of continued cooking once the food is removed from the source of heat. While this seems to violate a whole bunch of laws of thermodynamics, it's actually straightforward: the outer portion of the just-cooked food is hotter than the center portion, so the outer portion will transfer some of its heat into the center. You can think of it like pouring hot fudge sauce on top of ice cream: even though there's no external heat being added to the system, the ice cream melts because the hot fudge raises its temperature.

The amount of carryover depends upon the ma.s.s of the food and the heat gradient, but as a general rule, I find carryover for small grilled items is often about 5F / 3C. When grilling a steak or other "whole muscle" meat, pull it when it registers a few degrees lower at its core than your target temperature and let it rest for a few minutes for the heat to equalize.

NoteTo see how this works, try using a kitchen probe thermometer to record the temperature of a steak after removing it from the grill once it reaches 140F / 60C, recording data at 30-second intervals. You should see the core temperature peak at around 145F / 63C three minutes into the rest period for a small steak.Simple Seared SteakGet a cast iron pan good and hot over medium-high heat. Take a steak that's about 1 / 2.5 cm thick, rub lightly with olive oil, and sprinkle with salt and pepper. Drop the steak onto the cast iron pan and let it cook for two minutes. (Don't poke it! Just let it sit and sear.) After two minutes, flip and let cook for another two minutes. Flip again, reduce heat to medium and cook for five to seven minutes, until the center is about 135F / 57C. Let rest on cutting board for five minutes before serving.

Methods of Heat Transfer There are three methods of transferring heat into foods: conduction, convection, and radiation. While the heating method doesn't change the temperature at which chemical reactions occur, the rate of heat transfer is different among them, meaning that the length of time needed to cook identical steaks via each method will be different. The table below shows the common cooking techniques broken out by their primary means of heat transfer.

Conduction Conduction is the simplest type of heat transfer to understand because it's the most common: it's what you experience whenever you touch a cold countertop or grasp a warm cup of coffee. In cooking, those methods that transfer heat by direct contact between food and a hot material, such as the hot metal of a skillet, are conduction methods. Dropping a steak onto a hot cast iron pan, for example, causes thermal energy from the skillet to be transferred to the colder steak as the neighboring molecules distribute kinetic energy in an effort to equalize the difference in temperature. For more on thermal conductivity, see the Metals, Pans, and Hot Spots Metals, Pans, and Hot Spots sidebar in sidebar in Chapter2 Chapter2.

Conduction Convection Radiation Description Heat pa.s.ses by direct contact between two materials Heat pa.s.ses via movement of a heated material against a colder material Heat is transferred via electromagnetic radiation Example Steak touching pan; pan touching electric burner Hot water, hot air, or oil moving along outside of food Infrared radiation from charcoal Uses Sauteing Searing Dry heat methods: - - Baking/roasting - - Deep-fat frying Wet heat methods: - - Boiling - - Braising/water bath - - Pressure cooking - - Simmering/poaching - - Steaming Microwaving Broiling Grilling

[image]

Cooking methods listed by type of heat transfer. (Frying is a dry-heat method because it does not involve moisture.) Convection Convection methods of heat transfer-baking, roasting, boiling, steaming-all work by circulating a hot material against a cold one, causing the two materials to undergo conduction to transfer heat. In baking and roasting, the hot air of the oven imparts the heat; in boiling and steaming, it's the water that does this.

Those heat methods that involve water are called wet heat methods; all others fall into the dry heat category. One major difference between these two categories is that wet methods don't reach the temperatures necessary for Maillard reactions or caramelization (with the