Cooley's Cyclopaedia of Practical Receipts Volume I Part 108

_e._ (J. C. Thresh.) The author states that this process requires only a few hours, and quotes experiments, showing the accuracy of the results:--

Take 1250 gr. of bread (from middle of loaf) or flour, and char thoroughly in a platinum dish or on foil over a gas lamp. Powder the char and mix it with sufficient pure strong hydrochloric acid to make a thin cream. Boil gently for a few minutes, then add 100 c. c. of water, and continue the ebullition a few minutes longer. Dilute to 150 c. c., stir well, and filter off 120 c. c., which will contain the alumina from 1000 gr. of the bread or flour. To this filtrate add a slight excess of solution of ammonia, boil for a few seconds. Then let the precipitate subside, and decant the supernatant fluid. Add boiling water to the sediment, and again set aside to settle, and decant the clear fluid. Pa.s.s the fluids through a small filter to collect any particles of the precipitate which may have been suspended therein, and throw the filtrate away. Now add to the partially washed precipitate about a gram of pure caustic potash (or soda), warm, and pa.s.s the solution through the same filter employed for the previously decanted fluids. Wash the filter with hot water, to which a little KHO may be added, and proceed to precipitate the alumina in the filtrate by adding a few drops of dilute phosphoric acid and excess of pure acetic acid. Heat the solution and precipitate to the boiling point, and then wash the latter by decantation and filtration. Finally dry, ignite, and weigh. The weight of the resulting Al_{2}PO_{4} in grams, multiplied by 400, will give the amounts of ammonia alum in grains present in one pound of the bread or flour.

_f._ (Mr Crookes.) The bread of which at least 500 grains should be taken is first to be incinerated on a platinum or porcelain dish, until all volatile organic matter has been expelled, and a black carbonaceous ash remains. The temperature must not be raised much beyond the point necessary to effect this. Powder the coal thus obtained and add about thirty drops of oil of vitriol, and heat until vapours begin to rise; when sufficiently cool, add water, and boil for ten minutes. Filter and evaporate the filtrate until the fumes of sulphuric acid begin to be evolved, when 10 gr. of metallic tin and an excess of nitric acid must be added, together with water, drop by drop, until action between the acid and metal commences. When all the tin is oxidised, add water, and filter.

Evaporate the filtrate until fumes of sulphuric acid are again visible, when more water must be added, and the liquid again filtered if necessary.

To the clear solution now add tartaric acid, then ammonia in excess, and sulphide of ammonium. Evaporate the liquid containing the precipitate suspended to it, in a dish, until all the smell of sulphide of ammonium has disappeared. Filter, evaporate to dryness, and ignite to get rid of the organic matter. Powder the black ash, boil it in moderately strong hydrochloric acid, filter, add a crystal of chlorate of potash, and boil for a minute. Now add chloride of ammonium and ammonia, and boil for five minutes. If at the end of that time any precipitate is observed, it will be alumina. From the filtered solution, if oxalate of ammonia be added, the lime will be precipitated; and if to the filtrate from this, ammonia and phosphate of soda be added, the magnesia will come down.

Dr Dupre is of opinion that no baker should be fined in whose bread the amount of alumina found corresponds with less than 10 grains of potash alum in the 2-lb. loaf, unless there is direct evidence of adulteration by alum independent of the result of a.n.a.lysis.

Mr Crookes says, "By treatment with a trace of alum, flour with a doubtful soundness is endowed with soundness. For this purpose a proportion of alum is required which does not exceed 20 grains to a 4-lb. loaf.

2. COPPER:--_a._ Moisten the suspected bread with a few drops of a solution of ferrocyanide of pota.s.sium. It will a.s.sume a pinkish-brown colour if copper be present.

_b._ A little of the bread may be steeped in hot water, or, better still, in water soured with a little nitric acid, and the clear liquor squeezed or poured off, and tested with ferrocyanide of pota.s.sium, as before.

3. MAGNESIA:--Bread adulterated with magnesia, on digestion in hot water acidulated with sulphuric acid, furnishes a liquid which gives a white precipitate when tested with a solution of either carbonate of pota.s.sa or of carbonate of soda, especially on boiling.

4. SODA; POTa.s.sA:--Hot water after digestion on the ashes or charcoal turns turmeric paper brown. The liquid may be evaporated to dryness, redissolved in distilled water, slightly acidulated with hydrochloric acid, and tested with b.i.+.c.hloride of platinum. If a yellow crystalline precipitate forms, either at once or after some hours, it is potash; otherwise the alkali present is soda.

5. CHALK, WHITING, BURNT BONES, PLASTER OF PARIS, and similar substances are easily detected by calcining a little of the flour or bread in a clean open vessel, when the amount of ash left will indicate the quant.i.ty of adulteration. The quant.i.ty of the ash left by genuine bread or flour is very trifling indeed, about 2%.

=Microscopic Characters of Bread.= When bread is placed under the microscope, starch cells, broken up into angular ma.s.ses, or greatly enlarged, and stringy ma.s.ses of gluten are usually visible; besides these, when a microscope of high power is employed, bacteria of the rod-shaped variety may frequently be detected, the source of these being, probably, the yeast. Great caution and diligent observation are necessary to guard against the falling into the serious error of mistaking the many curious forms the broken-up wheat starch presents for adulterants. By practice and the constant examination of the characters of unadulterated bread, combined with a practical knowledge of the appearance different starch grains present, after being more or less changed in shape by cooking, the microscopist may identify rice-flour, bean-flour, and Indian millet.

Barley flour and potatoes, however, are very difficult of detection. There is very little difference in the shape of the barley-starch granule and that of the wheat, and in the process of bread-making the potato granules are so changed as to confuse all their distinctive characters. Bone-dust and a few other mineral adulterations may be detected by the microscope.

_Concluding Remarks._ A number of processes are used by cooks and confectioners to make the different varieties of fancy bread, cakes, puddings, &c., which vary according to the peculiar characteristic it is desired to communicate to them; but none of these articles properly belong to the trade of the common baker. Thus, some kinds of cakes and pastes are made to eat 'short,' as it is called, or are rendered less tenacious, and a species of brittleness imparted to them by the addition of starch, rice-flour, or sugar. In pastry a similar effect and peculiar lightness is produced by b.u.t.ter or lard, whilst in some articles white of egg, gum water, isingla.s.s, and other adhesive substances, are added to produce an exceedingly light and porous ma.s.s.

The chief varieties of bread at present in use in this country are known according to their shapes, as--BRICKS, COBURG, COTTAGE, BATCH, FRENCH ROLLS, and RYE BREAD. These vary in their quality, chiefly according to the flour of which they are formed, and their various flavours depend upon the heat of the oven in baking. The best WHITE BREAD is made from the purest wheat-flour; ordinary WHEATEN BREAD, of flour containing a little of the finest bran; SECONDS, from flour containing a still larger proportion of bran; and common HOUSEHOLD BREAD, from flour produced by grinding the whole substance of the grain, without any separation of the bran. The last variety is undoubtedly the most wholesome and nutritious, although that least frequently used. SYMNEL-BREAD, MANCHET or ROLL-BREAD, and FRENCH BREAD are varieties made of the purest flour, from the finest wheat, a little milk being usually added for rolls, and b.u.t.ter and eggs for choicer purposes. Several other minor kinds of bread are also made, varied by the addition of sundry trifles, as sugar, currants, and other palatable ingredients. The SCOTCH SHORTBREAD is made from a very thick dough, to which b.u.t.ter, sugar, orange-peel, and spices are added, according to the taste of the maker.

In the manufacture of white bread from damaged or inferior flour a large quant.i.ty of alum is employed by the fraudulent baker, as already noticed; but with the 'best flour' no alum is required. The utmost beauty, sponginess, and sweetness may be given to bread without the addition of one particle of alum, provided the best materials alone enter into its composition. As such materials are seldom employed by the bakers, the usual practice is to introduce 4 or 5 oz. of alum to every sack of flour, or about 1 oz. to each bushel; and very frequently fully double this quant.i.ty of alum is employed. But even this enormous quant.i.ty is often not the whole of the alum present in common bread; for the miller, in order to cheat the baker, puts in the 'doctor,' in the shape of 4 to 6 oz. of alum to the sack, whilst the baker, unconscious of this victimisation, subsequently uses a double dose of alum in order to cheat his customers.[229] The method of detecting this pernicious adulteration has been already explained. The proper quant.i.ty of salt is 4 lbs., and never more than 5 lbs., to the sack, or 1 lb. per bushel. One sack of the best flour, with 4 or 5 lbs. of salt, yields about 360 lbs. of good bread; and a sack of seconds, 345 to 350 lbs. of bread; each being moderately baked.

If the loaves are well-baked or over-baked, the product will be from 345 to 350 lbs. only; but if they are slack-baked or under-baked, from 370 lbs. to 385 lbs. of crumbling bread may be obtained from 1 sack of good white flour.

[Footnote 229: The common excuse of the bakers for using alum is, that without it the bread is not sufficiently white to please their customers, and that the batches are not easily parted into loaves after baking; but Liebig has shown that clear lime-water, which is perfectly harmless, will effect the same object if subst.i.tuted for the simple water used to make the dough.]

The attention of chemists has, at various times, been directed in search of some method to rectify or lessen the effects of bad harvesting and improper storage on grain, so that a damaged or inferior article might be rendered serviceable, and available for human food. Prof. E. Davy recommends the addition of 1/4 oz. of carbonate of magnesia to about every 3 lbs. of sour, melted, heated, and similarly damaged flour. This substance materially improves the quality of the bread, "even when made from the worst new seconds flour;" whilst it is said to be perfectly harmless; and the bread so prepared, for temporary use, is certainly un.o.bjectionable. What effects would arise from the daily consumption of such bread for several months has not been determined; but it is doubtful whether it would prove salutary. Indeed there are sufficient reasons for condemning the adoption of such bread in the general diet of a people for any very lengthened period.[230] Our own experiments in bread-making, extending over a long period of years, lead us to prefer carbonate or bicarbonate of soda for the purpose. Theoretically, the corresponding salts of pota.s.sa would be preferable. A mixture of equal parts of the bicarbonates of pota.s.sa and of soda will, perhaps, ultimately be found to be more useful than either substance used separately.

[Footnote 230: See GOITURE, MAGNESIA, &c.]

In times of scarcity and famine various substances, besides the flour of the cereals, have been made into bread, or have been mixed with it, in order to lessen the quant.i.ty of the former required by the people. For this purpose, almost every amylaceous vegetable at once plentiful and cheap has, in its turn, been eagerly appropriated. Acorns, beech-mast, the leguminous seeds, numerous starchy bulbous roots, and similar substances, have been employed, either in the form of meal, or made into an emulsion or jelly, which has been used instead of water to form the flour of bread-corn into a dough. At such times bran, the most nutritious and valuable portion of the grain, although usually rejected as worthless, has been retained in the flour, and has even been added to it in excess.

Birkenmayer, a brewer of Constance, during a period of scarcity, succeeded in manufacturing bread from the farinaceous residue of beer (brewer's grains). 10 _lbs._ of this substance, rubbed to a paste, with 1/2 _lb._ of yeast, 5 _lbs._ of ordinary meal, and a handful of salt, produces 14 _lbs._ of BLACK BREAD, which is said to be "both savoury and nouris.h.i.+ng."

The nutritious quality of brewer's grains is shown by their extensive employment at the present day as food for pigs and cattle, and particularly for milch cows. In like manner Iceland, Carragheen, and other mosses, have been made into bread, either alone, or mixed with flour or meal. They are used, in the first case, in the state of meal, in the same way as flour; in the second case, 7 _lbs._ of moss are directed to be boiled in 10 or 12 _galls._ of water, and the resulting glutinous liquid or jelly to be employed to make 70 _lbs._ of flour into dough, which is then fermented and baked in the usual way. It is said that flour thus produces fully double its weight of good household bread. A simpler plan is to mix 1 _lb._ of lichen meal with 3 or 4 _lbs._ of flour; the bitterness of the lichen having been first extracted by soaking it in cold water. Bread so prepared has of late been highly recommended for the delicate and dyspeptic. The modern baker is in the habit of mixing large quant.i.ties of potatoes with his bread, whenever he can purchase them at paying prices. Mealy potatoes are selected, and are carefully mashed or pulped, and the dry flour is worked into this pulp or dough, which is then mixed with the sponge in the usual manner. For inferior bread, equal weights of potato pulp and dry flour are often used. Bread so prepared eats 'short,' and is deficient in sponginess, and in that fine yellowish-white tint which forms one of the characteristics of pure wheaten bread, More recently, rice boiled with water to a jelly has got into very extensive use among the bakers. A 'sponge' is made with a portion of the jelly thickened with some flour, and the whole process is conducted in the ordinary manner, except that the fermentation is generally more slowly conducted and allowed to proceed for a longer period. Flour so treated yields fully 50% more bread than when merely mixed up with yeast and water. This const.i.tutes the process of Messrs Morian, Martin, and Journet, of Paris, which was tested, a few years since, at Marylebone Workhouse. The experiment succeeded, but the only result to the public has been, that the common bakers have adopted the plan, and now very generally surcharge their bread with such an excess of water that, in many cases, it only possesses two thirds the amount of nourishment which it did before the publication of the system just referred to. Unfortunately, the cupidity of dishonest tradesmen appears to be continually impelling them to avail themselves of the exertions of philanthropists and the discoveries of science, in order to increase their profits, regardless alike of the quality of their commodities and the health of their customers. Bread containing an excess of water rapidly becomes sour and mouldy, and is apt to disorder the digestive functions of those who eat it.

From the experiments of Dr Colquhoun, it appears that the starch of flour is partially converted into sugar during the process of fermenting and baking the dough, and thus contributes to the sweetness of the bread. He proposes to add to the flour, arrow-root, the farina of potatoes, and similar amylaceous substances, made into a jelly with hot water, for this purpose. Dr Percival has recommended the addition of salep with the same intention. 1 _oz._ of salep, dissolved in 1 quart of water; 2 _lbs._ of flour; 80 grs. of salt; and 2 _oz._ of yeast, gave 3 _lbs._ 2 _oz._ of good bread. The same weight of materials, without the salep, gave only 2-3/4 _lbs._ If too much salep is added, it gives its peculiar flavour to the bread.

In reference to the above subst.i.tutions, and to the relative quant.i.ty of bread produced from any given weight of flour, the reader should remember that the mere increase of the weight or bulk of the product does not carry with it a corresponding increase of the nutritive elements contained in the flour. These remain the same in all cases; and just in proportion as the product, in bread, is greater, will be the decrease in the value of such bread as food. So also with potatoes, rice, and other farinaceous and pulpy substances used as subst.i.tutes for wheat-flour. Their poverty in nitrogenous matter, or flesh-formers, is so great, that the greatly increased quant.i.ty required as food to support the body, apart from mere inconvenience, more than compensates for their apparent low price. Thus, good wheaten bread, at 2_d._ per _lb._, is more than twice as cheap as potatoes at 1_d._; for, a.s.suming 2 _lbs._ of the first as a day's food, 10 _lbs._ of the last will be required for the same purpose; and even this large quant.i.ty will scarcely effect the desired object. Liebig has demonstrated that, regard being had to the nutritive power of wheat, it is, under all ordinary circ.u.mstances, the cheapest article of food provided by nature for man.

We have not entered into particulars respecting oven management, because, on the large scale, it is thoroughly understood by every practical baker.

For the instruction of the busy housewife, however, we may state that the oven should always be sufficiently heated before the bread is put into it, in order that the gas contained in the cells of the 'sponge' may be expanded as rapidly as possible by the heat, and the resulting light ma.s.s quickly rendered sufficiently solid to prevent its subsequent collapse.

The heat should also be maintained at nearly the same temperature during the whole of the time the bread is submitted to its action. In general, with ordinary kitchen ovens properly heated, 30 minutes' baking is sufficient for one-pound loaves and cakes; and 15 minutes in addition for every pound after the first for larger ones. Thus, a 1 _lb._ loaf requires 1/2 hour; a 2 _lb._ loaf 3/4 hour; and a 4 _lb._ loaf, 1-1/4 hour.

It is the common ambition of the English baker to give that peculiar tint to the crust of his bread in the process of baking which is so highly esteemed by connoisseurs, and so successfully produced by the Viennese and Parisians. It has been long known at Vienna that if the hearth of an oven be cleaned with a moistened wisp of straw, the crust of bread baked in it immediately afterwards presents a beautiful yellow tint. It was thence inferred that this peculiarity depends on the vapour, which being condensed on the roof of the oven, falls back on the bread. At Paris, in order to secure with certainty so desirable an appearance, the hearth of the oven is generally laid so as to form an inclined plane, with a rise of about 11 inches in 3 feet; and the arched roof is built lower at the end nearest the door, as compared with the further extremity. When the oven is charged the entrance is closed with a wet bundle of straw. By this arrangement the steam is driven down on the bread, and a golden-yellow crust is given to it, as if it had been previously covered with the yolk of an egg.

Pure wheaten bread is one of the most wholesome articles of food, and has been justly termed the 'staff of life,' and a certain proportion of it should be taken at every meal.

_New and Stale Bread._--As has been just stated, bread which has been kept for 24 hours after baking is more digestible, and therefore preferable to that which has been newly baked. This latter exhibits a well-known elastic appearance, and possesses a certain degree of moisture which renders its taste more agreeable to most persons than bread which has been kept for a day or two, and has become firmer and drier in appearance, and which is commonly termed _stale_. It is very generally supposed that this change in properties in bread which has been kept for a few days, is owing to the loss of water.

This, however, is not the case. The crum of newly baked bread when cold contains about 45 per cent. of water, and that of stale bread contains almost exactly the same proportion.

The difference in properties between the two is due simply to difference in molecular arrangement. Boussingault found that a loaf which had been kept for six days, though it had become very stale, had not lost more than 1 per cent. of its weight when new. The same loaf was then placed in the oven for an hour, and at the end of that time it had acquired all the properties and appearance of new bread, although during the second baking it lost 3-1/2 per cent. of water. In another experiment a portion of bread was allowed to become stale when enclosed in a tight case, to prevent loss of water by evaporation; it was then heated, and was thus restored to the condition of new bread; these effects were produced alternately, many times in succession, upon the same piece of bread; a heat of about 131 F.

was found to be sufficient to convert stale into new bread. Every person who has seen a thick slice of stale bread toasted may have satisfied himself that the crum has during this operation been converted into the same condition as that of new bread.

_Fungi._ When bread has been kept a few days and has become stale, certain species of fungi show themselves in it: these are the _penicillium glauc.u.m_, which is the green mould of cheese; the _fermentum cerivisiae_ or yeast fungus; the _oidium auriantiac.u.m_ or orange-red mould; the _puccinia graminis_ and others. Excess of salt added to the bread prevents the development of these fungi.

_Diseases arising from the employment of unsound Flour and Bread._--The flour may be ergotised or grown, and fermenting from the presence of fungi. All the poisonous symptoms of ergot are induced from continuously partaking of bread made with ergotised flour. Dry gangrene is one of the most virulent forms of poisoning caused by partaking of ergotised bread.

Severe intestinal derangement is an accompaniment of the milder forms of poisoning. Ergot is more frequently present in rye flour than in wheat.

Fermenting bread is a fertile source of dyspepsia, whilst acid bread causes diarrha. This latter malady is also caused by the presence in bread of the _oidium aurantiac.u.m_. Professors Varnell and Tuson state that mouldy oats, the mould being caused by a fungus (the _aspergillus_), have given rise to paralytic symptoms in horses, so that the presence of these fungi in oats used for making bread should always be regarded with considerable caution.

It has not been demonstrated that the acarus so common in flour has had any injurious effect when eaten. When well fermented and baked bread is very easy of digestion. It should never be eaten until it has stood at least 24 hours after being taken out of the oven. When newer, bread is apt to disagree with the stomach, frequently producing indigestion, biliousness, diarrha, dyspepsia, and other like ailments. Bread prepared from meal containing the whole of the bran is the most nutritious and digestible, and should alone be given to children and growing persons, and eaten by the dyspeptic and delicate. Young infants should never be fed upon bread. See ALEUROMETER, ALUM, FLOUR, WHEAT, &c.

=Bread, Aerated.= The best description of unfermented bread is that manufactured by the process of Dr DAUGLISH. The method of manufacture has this advantage:--During the whole of the operation neither the flour nor the dough comes into contact with the flesh of the workman. For a full description of the method of preparing this article, _see_ Watts' 'Dic. of Chemistry.' See BREAD, UNFERMENTED.

=Bread, Amer'ican.= From American barreled flour. "14 _lbs._ of American flour will make 21-1/2 _lbs._ of bread; whereas the best sort of English flour produces only 18-1/2 _lbs._ of bread." (Mrs Rundell.) This arises from the superior quality of the wheat used in its production; and also from its being kiln-dried before grinding, by which much water is driven off.

=Bread, Bee.= The matter collected by bees to form the bottom of the hive.

It resembles a mixture of resin and wax. Its fumes were formerly thought to be anti-asthmatic.

=Bread, Bran.= 1. From the whole meal, without sifting out any of the bran.

2. By adding about 3 _oz._ of bran to every _lb._ of ordinary flour.

=Bread, Ca.s.sava=, is made from the root of the _manihot_, by first expressing the juice, then grinding the residue into a coa.r.s.e meal, and baking it in the form of cakes upon thin iron plates. When steeped in oil, and flavoured with cayenne, and slightly broiled upon a gridiron, it is not unpalatable.

=Bread, Extemporaneous.= See BREAD, UNFERMENTED.

=Bread, French.= _Prep._ 1. From fine flour, as the best white bread. For the better kinds, and for those intended for rolls and small fancy bread, the sponge and dough is commonly wetted with milk and water, and, occasionally, a very little b.u.t.ter is added. "When the rolls or small fancy loaves have lain in a quick oven about a quarter of an hour, turn them on the other side for about a quarter of an hour longer. Then take them out and chip them with a knife, which will make them look spongy, and of a fine yellow; whereas rasping takes off this fine colour, and renders their look less inviting."

2. FRENCH SOUP-BREAD. From fine flour, but employing fully double the usual quant.i.ty of salt. It is baked in thin loaves, so as to be nearly all crust, by which means it becomes more soluble in hot soup.

=Bread, Hick's Pat'ent.= This is ordinary bread baked in an oven so arranged that the vapours arising during the process are condensed in a suitable receiver. The condensed liquor is a crude, weak spirit, produced during the fermentation of the dough, and possesses little commercial value; indeed, insufficient to pay for the expenses attending its collection. Besides which, the bread prepared under this patent was rejected by the vulgar, who flocked to the shops of the neighbouring bakers, who professed to sell their bread with "the gin in it."

=Bread, Household.= This name is commonly given to bread made with flour from which only the coa.r.s.er portion of the bran has been removed; and to bread prepared from a mixture of flour and potatoes. The following are examples:--

1. (Rev. Mr Haggett.) Remove the flake-bran from flour, 14 _lbs._; boil the bran in 1 _gall._ of water until reduced to 7 pints; strain, cool, and knead in the flour, adding salt and yeast as for other bread. Very wholesome.

2. Flour, 7 _lbs._; mealy potatoes (well mashed), 3 _lbs._; as before.

Objectionable for the reasons already given.

=Bread, Leav'ened.= (lev'-). Using leaven instead of yeast, and in the same way. About 1 _lb._ to each bushel of flour is usually sufficient. The more leaven used, the lighter the bread made with it will be; and the fresher and sweeter the leaven, the less sour will it taste. Leaven, except among the Jews and sailors, is now superseded by yeast.

=Bread, London White.= The common proportions of the London bakers are--Flour, 1 sack; common salt, 4-1/2 lbs.; alum, 5 oz.; yeast, 4 pints; warm water for the sponge (about), 3 galls. The process has been already noticed.