This is one of the sophistications of the articles of food most commonly practised in this metropolis, where the goodness of bread is estimated entirely by its whiteness. It is therefore usual to add a certain quantity of alum to the dough; this improves the look of the bread very much, and renders it whiter and firmer. Good, white, and porous bread, may certainly be manufactured from good wheaten flour alone; but to produce the degree of whiteness rendered indispensable by the caprice of the consumers in London, it is necessary (unless the very best flour is employed,) that the dough should be bleached; and no substance has hitherto been found to answer this purpose better than alum.

Without this salt it is impossible to make bread, from the kind of flour usually employed by the London bakers, so white, as that which is commonly sold in the metropolis.

If the alum be omitted, the bread has a slight yellowish grey hue—as may be seen in the instance of what is called home-made bread, of private families. Such bread remains longer moist than bread made with alum; yet it is not so light, and full of eyes, or porous, and it has also a different taste.

The quantity of alum requisite to produce the required whiteness and porosity depends entirely upon the genuineness of the flour, and the quality of the grain from which the flour is obtained. The mealman makes different sorts of flour from the same kind of grain. The best flour is mostly used by the biscuit bakers and pastry cooks, and the inferior sorts in the making of bread. The bakers' flour is very often made of the worst kinds of damaged foreign wheat, and other cereal grains mixed with them in grinding the wheat into flour. In this capital, no fewer than six distinct kinds of wheaten flour are brought into market. They are called fine flour, seconds, middlings, fine middlings, coarse middlings, and twenty-penny flour. Common garden beans, and pease, are also frequently ground up among the London bread flour.

I have been assured by several bakers, on whose testimony I can rely, that the small profit attached to the bakers' trade, and the bad quality of the flour, induces the generality of the London bakers to use alum in the making of their bread.

The smallest quantity of alum that can be employed with effect to produce a white, light, and porous bread, from an inferior kind of flour, I have my own baker's authority to state, is from three to four ounces to a sack of flour, weighing 240 pounds. The alum is either mixed well in the form of powder, with a quantity of flour previously made into a liquid paste with water, and then incorporated with the dough; or the alum is dissolved in the water employed for mixing up the whole quantity of the flour for making the dough.

Let us suppose that the baker intends to convert five bushels, or a sack of flour, into loaves with the least adulteration practised. He pours the flour into the kneading trough, and sifts it through a fine wire sieve, which makes it lie very light, and serves to separate any impurities with which the flour may be mixed. Two ounces of alum are then dissolved in about a quart of boiling water, and the solution poured into the seasoning-tub. Four or five pounds of salt are likewise put into the tub, and a pailful of hot-water. When this mixture has cooled down to the temperature of about 84°, three or four pints of yeast are added; the whole is mixed, strained through the seasoning sieve, emptied into a hole in the flour, and mixed up with the requisite portion of it to the consistence of a thick batter. Some dry flour is then sprinkled over the top, and it is covered up with cloths.

In this situation it is left about three hours. It gradually swells and breaks through the dry flour scattered on its surface. An additional quantity of warm water, in which one ounce of alum is dissolved, is now added, and the dough is made up into a paste as before; the whole is then covered up. In this situation it is left for a few hours.

The whole is then intimately kneaded with more water for upwards of an hour. The dough is cut into pieces with a knife, and penned to one side of the trough; some dry flour is sprinkled over it, and it is left in this state for about four hours. It is then kneaded again for half-an-hour. The dough is now cut into pieces and weighed, in order to furnish the requisite quantity for each loaf. The loaves are left in the oven about two hours and a half. When taken out, they are carefully covered up, to prevent as much as possible the loss of weight.[43]

The following account of making a sack, of five bushels of flour into bread, is taken from Dr. P. Markham's Considerations on the Ingredients used in the Adulteration of Bread Flour, and Bread, p. 21:

The theory of the bleaching property of alum, as manifested in the panification of an inferior kind of flour, is by no means well understood; and indeed it is really surprising that the effect should be produced by so small a quantity of that substance, two or three ounces of alum being sufficient for a sack of flour.

From experiments in which I have been employed, with the assistance of skilful bakers, I am authorised to state, that without the addition of alum, it does not appear possible to make white, light, and porous bread, such as is used in this metropolis, unless the flour be of the very best quality.

Another substance employed by fraudulent bakers, is subcarbonate of ammonia. With this salt, they realise the important consideration of producing light and porous bread, from spoiled, or what is technically called sour flour. This salt which becomes wholly converted into a gaseous state during the operation of baking, causes the dough to swell up into air bubbles, which carry before them the stiff dough, and thus it renders the dough porous; the salt itself is, at the same time, totally volatilised during the operation of baking. Thus not a vestige of carbonate of ammonia remains in the bread. This salt is also largely employed by the biscuit and ginger-bread bakers.

Potatoes are likewise largely, and perhaps constantly, used by fraudulent bakers, as a cheap ingredient, to enhance their profit. The potatoes being boiled, are triturated, passed through a sieve, and incorporated with the dough by kneading. This adulteration does not materially injure the bread. The bakers assert, that the bad quality of the flour renders the addition of potatoes advantageous as well to the baker as to the purchaser, and that without this admixture in the manufacture of bread, it would be impossible to carry on the trade of a baker. But the grievance is, that the same price is taken for a potatoe loaf, as for a loaf of genuine bread, though it must cost the baker less.

I have witness, that five bushels of flour, three ounces of alum, six pounds of salt, one bushel of potatoes boiled into a stiff paste, and three quarts of yeast, with the requisite quantity of water, produce a white, light, and highly palatable bread.

Such are the artifices practised in the preparation of bread,[45] and it must be allowed, on contrasting them with those sophistications practised by manufacturers of other articles of food, that they are comparatively unimportant. However, some medical men have no hesitation in attributing many diseases incidental to children to the use of eating adulterated bread; others again will not admit these allegations: they persuade themselves that the small quantity of alum added to the bread (perhaps upon an average, from eight to ten grains to a quartern loaf,) is absolutely harmless.

Dr. Edmund Davy, Professor of Chemistry, at the Cork Institution, has communicated the following important facts to the public concerning the manufacture of bread.

"The carbonate of magnesia of the shops, when well mixed with flour, in the proportion of from twenty to forty grains to a pound of flour, materially improves it for the purpose of making bread.

"Loaves made with the addition of carbonate of magnesia, rise well in the oven; and after being baked, the bread is light and spongy, has a good taste, and keeps well. In cases when the new flour is of an indifferent quality, from twenty to thirty grains of carbonate of magnesia to a pound of the flour will considerably improve the bread. When the flour is of the worst quality, forty grains to a pound of flour seem necessary to produce the same effect.

"As the improvement in the bread from new flour depends upon the carbonate of magnesia, it is necessary that care should be taken to mix it intimately with the flour, previous to the making of the dough.

"Mr. Davy made a great number of comparative experiments with other substances, mixed in different proportions with new bread flour. The fixed alkalies, both in their pure and carbonated state, when used in small quantity, to a certain extent were found to improve the bread made from new flour; but no substance was so efficacious in this respect as carbonate of magnesia.

"The greater number of his experiments were performed on the worst new seconds flour Mr. Davy could procure. He also made some trials on seconds and firsts of different quality. In some cases the results were more striking and satisfactory than in others; but in every instance the improvement of the bread, by carbonate of magnesia, was obvious.

"Mr. Davy observes, that a pound of carbonate of magnesia would be sufficient to mix with two hundred and fifty-six pounds of new flour, or at the rate of thirty grains to the pound. And supposing a pound of carbonate of magnesia to cost half-a-crown, the additional expense would be only half a farthing in the pound of flour.

"Mr. Davy conceives that not the slightest danger can be apprehended from the use of such an innocent substance, as the carbonate of magnesia, in such small proportion as is necessary to improve bread from new flour."

METHOD OF DETECTING THE PRESENCE OF ALUM IN BREAD.

Pour upon two ounces of the suspected bread, half a pint of boiling distilled water; boil the mixture for a few minutes, and filter it through unsized paper. Evaporate the fluid, to about one fourth of its original bulk, and let gradually fall into the clear fluid a solution of muriate of barytes. If a copious white precipitate ensues, which does not disappear by the addition of pure nitric acid, the presence of alum may be suspected. Bread, made without alum, produces, when assayed in this manner, merely a very slight precipitate, which originates from a minute portion of sulphate of magnesia contained in all common salt of commerce; and bread made with salt freed from sulphate of magnesia, produces an infusion with water, which does not become disturbed by the barytic test.

Other means of detecting all the constituent parts of alum, namely, the alumine, sulphuric acid, and potash, so as to render the presence of the alum unequivocal, will readily suggest itself to those who are familiar with analytical chemistry; namely: one of the readiest means is, to decompose the vegetable matter of the bread, by the action of chlorate of potash, in a platina crucible, at a red heat, and then to assay the residuary mass—by means of muriate of barytes, for sulphuric acid; by ammonia, for alumine; and by muriate of platina, for potash[46]. The above method of detecting the presence of alum, must therefore be taken with some limitation.

There is no unequivocal test for detecting in a ready manner the presence of alum in bread, on account of the impurity of the common salt used in the making of bread. If we could, in the ordinary way of bread making, employ common salt, absolutely free from foreign saline substances, the mode of detecting the presence of alum, or at least one of its constituent parts, namely, the sulphuric acid, would be very easy. Some conjecture may, nevertheless, be formed of the presence, or absence, of alum, by assaying the infusion of bread in the manner stated, p. 109, and comparing the assay with the results afforded by an infusion of home-made or household bread, known to be genuine, and actually assayed in a similar manner.

EASY METHOD OF JUDGING OF THE GOODNESS OF BREAD CORN, AND BREAD-FLOUR.

Millers judge of the goodness of bread corn by the quantity of bran which the grain produces.

Such grains as are full and plump, that have a bright and shining appearance, without any shrivelling and shrinking in the covering of the skin, are the best; for wrinkled grains have a greater quantity of skin, or bran, than such as are sound or plump.

Pastry-cooks and bakers judge of the goodness of flour in the manner in which it comports itself in kneading. The best kind of wheaten flour assumes, at the instant it is formed into paste by the addition of water, a very gluey, ductile, and elastic paste, easy to be kneaded, and which may be elongated, flattened, and drawn in every direction, without breaking.

For the following fact we are indebted to Mr. Hatchet.

"Grain which has been heated or burnt in the stack, may in the following manner be rendered fit for being made into bread:

"The wheat must be put into a vessel capable of holding at least three times the quantity, and the vessel filled with boiling water; the grain should then be occasionally stirred, and the hollow decayed grains, which float, may be removed. When the water has become cold, or in about half an hour, it is drawn off. Then rince the corn with cold water, and, having completely drained it, spread it thinly on the floor of a kiln, and thus thoroughly dry it, stirring and turning it frequently during this part of the process."[47]

[43] The sack of marketable flour is by law obliged to weigh 240 pounds, which is the produce of five bushels of wheat, and is upon an average supposed to make eighty quartern loaves of bread; and consequently sixteen of such loaves are made from each bushel of good wheat. It is admitted, however, that two or three loaves more than the above quantity can be made from the sack of flour, when it is the genuine produce of good wheat; that is, in the proportion of about sixteen and a half loaves from each bushel of sound grain, and, it may be presumed, sixteen from a bushel of medium corn. The expense, in London, of making the sack of flour into bread, and disposing of it, is about nine shillings.

A bushel of wheat, upon an average, weighs sixty-one pounds; when ground, the meal weighs 60-3/4 lbs.; which, on being dressed, produces 46-3/4 lbs. of flour, of the sort called seconds; which alone is used for the making of bread in London and throughout the greater part of this country; and of pollard and bran 12-3/4 lbs., which quantity, when bolted, produces 3 lbs. of fine flour, this, when sifted, produces in good second flour 1-1/4 lb.