Part 39

Unfortunately not all flour of good colour is sound for bread-making purposes. Wheat which has been harvested in a damp condition, or has been thoroughly soaked, by drenching showers previous to cutting, or has got wet in the stook, is liable, unless carefully handled, to produce flour that will only bake flat, sodden loaves. Wheat which has received too much rain as it is approaching maturity, and has then been exposed to strong sunlight, is peculiarly liable to sprout. This seems to happen not infrequently to La Plata wheat, and though wheat shippers in that country are usually careful to clean off the little green spikes, this outward cleansing does not remedy the mischief wrought to the internal constitution of the berry. Such wheat makes flour lacking in strength and stability. Its gluten is immature and low in percentage, while the soluble albuminoids are in high percentage and in a more or less active diastasic state. The starch granules are liable to have weakened or fissured walls, and the proportion of moisture and of soluble extract will be high. With regard to the beneficial action of kiln or other drying on damp flour, William Jago was convinced by a series of experiments that the gentle artificial drying of flour increases its water-absorbing capacity to about three times the amount of water lost by evaporation. On the other hand, a damp flour dried too quickly and at too great a heat is liable to be made more instead of less susceptible to diastasic changes.

_Alum._--Strictly speaking, when employed with weak and unstable flours alum is a remedial agent. The popular idea that it acts as a kind of bleacher of flour, having the faculty of converting flour that is dark-coloured through containing a sensible proportion of branny

## particles and woody fibre, into white-coloured loaves, is erroneous.

Its action as a producer of white bread is indirect, not direct, though it is none the less effective. It seems to act as a brace to or steadier of unstable gluten. If from the same wheat a certain proportion of gluten be extracted and divided into two parts, of which one is placed in a glass of water containing a strong solution of alum, and the other in a glass of plain water, the gluten in the latter case will become spent days and perhaps weeks before the sample in the alumed water is disintegrated. The place of alum in the process of fermentation is well marked. By holding together unstable gluten, it checks the diastasic action, and the proportion of starch converted into glucose (grape sugar) is reduced, with the result that a whiter and more porous loaf is produced. It is generally admitted that by the use of alum more or less eatable bread may be baked from flour which otherwise could hardly be made into bread at all. Strictly, therefore, this substance is not an adulterant, inasmuch as it is not a substitute in any sense for flour. But it is admittedly unwholesome, and therefore its legal interdiction for alimentary purposes is quite justifiable. Another aspect of the use of alum is that it is employed for the purpose of enabling bakers to use poor flour.

A fairly satisfactory test for alum in bread (or flour) is afforded by an alkaline solution of logwood and a saturated solution of ammonium carbonate. The presence of alum is shown by a lavender or full blue colour. The depth of the tint is said to be a rough guide to the quantity of alum present. According to Jago this test is so sensitive that it has resulted in the detection of 7 grains of alum in a 4-lb loaf.

Besides alum, small quantities of copper sulphate have been used for checking diastasis and retarding fermentation. This substance has the same effect as alum, but as all copper salts are active poisons, the employment of copper sulphate is most strongly to be condemned.

_Lime-water._--The object of using either alum or copper sulphate is to check over-rapid diastasis during fermentation. Baron Liebig pointed out a much less objectionable means of attaining the same end by means of lime-water, about 1-1/2 oz. of fresh quicklime being dissolved in the water used for doughing one sack of flour. Bread made in this way is said to be spongy in texture, of agreeable flavour, and perfectly free from acidity. In the baked loaf the lime is transformed into calcium carbonate (chalk) by the carbon dioxide resulting from the panary fermentation. It is said that an increased yield of bread may be obtained by the use of lime-water; the explanation may be that lime-water, by retarding the degradation of the gluten and the diastasis of the starch, increases the water-retaining power of the flour, so that the same weight of flour yields a greater volume of bread.

_Unvesiculated and Vesiculated Bread._--Wheaten bread may be divided into two main divisions, unvesiculated and vesiculated. The term vesiculated simply means provided with vesicles, or small membranous cavities, such as are found in all bread that has been treated by yeast, leaven or any other agent for rendering it spongiform in structure by the action of carbonic acid gas. Nearly all bread eaten by civilized folk is vesiculated, though there are different methods and processes for attaining this result. Into the category of unvesiculated bread enter such products as the Australian damper, a flat cake prepared from flour, water and salt, and baked in the hot ashes of a wood fire. The dough is spread on a flat stone and covered with a tin plate, while the hot ashes are heaped around and over it; the heat should not be much in excess of 212 deg. Fahr. The scone, the bannock and other similar cakes, still much appreciated in Scotland and the north of England, are also examples of unvesiculated bread. They are baked on hot plates or "griddles," on hearths, and sometimes in ovens. Biscuits differ from these cakes in the fact that they are baked by a high instead of a moderate heat. But they enter so far into the class of unvesiculated bread that they are generally prepared without the aid of any such aerating agent as carbon dioxide. (See BISCUIT.)

Vesiculated bread is now the only article of diet made from flour to which the term bread is applied, and there are various ways of producing the spongiform texture by which it is characterized. The ordinary and doubtless the most satisfactory way is by developing the carbon dioxide within the dough itself by the use of yeast (q.v.) or leaven, which sets up alcoholic fermentation, splitting up the saccharine matters in the flour into alcohol and carbon dioxide. The latter is retained by the dough and distends it, causing the bread to "rise." Or the carbon dioxide may be artificially introduced, as in the so-called "aerated" bread (see below), or it may be produced by the agency of certain chemicals, as for instance of baking powders.

Baking powders.

Such powders are mixtures which, under the influence of either water or heat, evolve carbon dioxide. These powders have been divided by Jago into three groups:--(1) _Tartrate_ powders, in which the acid constituent is either free or partly combined tartaric acid; (2) _Phosphate_ powders, in which the acid is some form of phosphoric acid; (3) _Alum_ powders. All these powders have a more or less aperient

## action on the human system. Tartrate powders have the disadvantage that

both commercial tartaric acid and cream of tartar frequently contain lead, a poisonous substance. Phosphate powders are less open to objection, as they are more easy to obtain free from lead and other metallic impurities. Alum powders contain potassium bisulphate and alum. It is somewhat remarkable that while the presence of alum in bread is regarded by the law of England as adulteration, its use in baking powder was pronounced legal in _James_ v. _Jones_, 1894, 1, Q.B. 304, on the ground that baking powder is not food within the meaning of the Sale of Food and Drugs Act 1875. In making wholemeal bread, hydrochloric acid and sodium bicarbonate are often used in such proportions that they neutralize each other. Carbon dioxide is evolved and raises the dough. In preparing wholemeal bread the use of this combination has the advantage that the acid acting rapidly on the sodium bicarbonate soon produces enough carbon dioxide to aerate the dough, and thus hasten its entry into the oven. Wholemeal flour contains so large a proportion of cerealin that diastasis is apt to proceed rapidly, the result being a clammy, sodden loaf. For this reason, perhaps the so-called aerated process is even more suitable for making wholemeal than white bread.

Methods of making dough.

Methods of dough-making differ in different countries, and even in different parts of the same land. In the _off hand_ method the dough is made right off, without any preliminary stages of ferment or sponge. This plan is sometimes adopted for making tin bread, and occasionally for crusty loaves. For tin bread a strong flour would be used and made into a slack dough, and about 1-1/2 lb. to 2 lb. of distillers' yeast would be used for the sack (280 lb.) of flour, occasionally with the addition of a little brewers' yeast. Salt is used in the proportion of 3 lb. to 3-1/2 lb. per sack. Formerly also it was the custom to add 10-14 lb. of boiled potatoes, but the use of potatoes has greatly decreased. A tin-bread dough would be made slack, with about 70 quarts of water to the sack, and after being mixed, would be fermented at a temperature of 76-80 deg. Fahr. It should lie for about ten hours. A dough for crusty bread such as cottage loaves, would be made much tighter, not more than 60 quarts of water being allowed to the sack. It would be fermented at a higher temperature, and would not lie more than about six hours. A slack dough is much less laborious to work (when the dough is hand-made) than a tight dough, for which a mechanical kneader is very suitable, but as a matter of fact the use of machinery (see below) is still the exception, not the rule. When a stiff dough is made by hand, it is usually made somewhat slack to begin with, and then "cut back" and "dusted" at regular intervals, that is to say, more and more flour is added till a dough of the required consistency has been obtained. (In the British baker's vocabulary "dust" means flour, and good dust stands for good flour.) This system, on the one hand, saves the labour involved for "sponging" and other operations, and the bread is produced in less time; but on the other hand more yeast is used, and bakers generally hold that the system sacrifices the colour and texture of the loaf to convenience of working and yield. The high porportion of yeast enables the dough to carry a large quantity of water, and about 104 4-lb. loaves to the sack is said by Jago to be a not unusual yield in the case of slack doughs. But such a result would only be possible with very strong flour. In an ordinary way 96 loaves to the sack is a very high yield, unattainable except with strong flour, and probably the average yield is not more than 90 loaves to the sack. In London the manager of a "tied" shop is usually held to account for 92 loaves to the sack.

In the _ferment and dough_ system, the ferment usually consists of 10 to 14 lb. of potatoes to the sack of flour, boiled or steamed, and mashed with water, so as to yield about 3 gallons of liquor. There are several substitutes for potatoes, including raw and scalded flour, malt, malt extracts, &c.; brewers' or distillers' yeast may also be used. A ferment should contain saccharine matters and yeast stimulants in such a form as to favour the growth and reproduction of yeast in a vigorous condition. Hence it should not be too concentrated. About six hours are required for its preparation. It is added, together with 2 to 3 lb. of salt, to the dough, which is prepared with about 56 quarts of water to the sack, and worked at a temperature of 80-84 deg. Fahr. The dough is allowed to lie from two to five hours according to the flour used, the character of the ferment, and the working temperature. In this system the proportion of strong flour is usually reduced to 40% of the dough, and no doubt in some cases only soft or weak flours are used. Naturally the yield of bread is not so high as in the case of an off hand dough made entirely from strong flour, and it will probably not exceed 90 loaves to the sack. This method has many advantages. After the ferment is made the labour required is not much greater than with the off hand doughs, and less yeast is required, while potatoes, which are somewhat troublesome, from the necessary cleaning, can be replaced by the substitutes already mentioned. The method produces good-looking and palatable bread, though the loaves should be eaten within some twelve hours of leaving the oven.

The _sponge and dough_ system, which is probably in widest use in England, is adapted to almost every kind of bread, and has the advantage that any kind of flour can be employed. The stronger flours which need long fermentation can be and usually are used in the "sponge" stage, while soft flours are utilized in the dough. (The sponge is a certain proportion, varying from a quarter to one-half, of the flour necessary for making the batch.) In London the baker often uses for the sponge a bag (140 lb) of American spring wheat flour, and for the dough a sack (280 lb) of British milled flour, which, whether it be country flour milled largely from English wheat or London milled, is always softer and weaker than that used for the sponge. The sponge is made very slack, 26 to 32 quarts of water being used to say 100 lb. of flour. Yeast, either distillers' or brewers', must be added, in proportions varying according to its character and strength. Of distillers' yeast 6 to 10 oz. may be used for 280 lb. of flour (including sponge and dough). Salt is added to the sponge sparingly, at the rate of about 1/2 lb. to the sack of 280 lb. The object of making the sponge so slack is to quicken the fermentation. When set the sponge is allowed to ferment from six to ten hours, according to temperature and other conditions. Sometimes all the water it is intended to use is put into the sponge, which is then known as a "batter" sponge. The sponge, when ready, is incorporated with the rest of the flour to which the necessary amount of water and salt is added. The whole mass is then doughed up into the requisite consistency, the dough being allowed to lie for about two hours. Bread made by this method, always assuming that over-fermentation has been avoided, is of good appearance, presenting a bold loaf, with even texture and a nice sheen. Owing to the use of soft flours, the flavour should be agreeable, and the loaves ought to keep much longer than bread made by ferment and dough. The yield may rise as high as 96 loaves per sack, if strong flour has been used in the sponge.

A combination of the above two methods, known as the _ferment, sponge and dough_ system, is often used with brewers' yeast. In this case the yeast is not added to the sponge direct, but goes into the ferment. This method is rather in favour with bakers who make their own yeast.

The system of bread-making generally used in Scotland is known as the _flour barm, sponge and dough_. The barm is a combination of a malt and hop yeast, with a slow, scalded flour ferment. To make the so-called "virgin" barm a Scottish baker would use a 30-gallon tub; a smaller vessel for malt-mashing; 10 lb. malt; 3 oz. hops and a jar for infusing them; 40 lb flour; 2 to 3 oz. malt; 8 to 12 oz. sugar, and 18 gallons of boiling water. With these materials a powerful ferment is produced, which it is considered best to use in the sponge the fourth or fifth day after brewing. The sponges used in Scotland are "half" or "quarter." About 6 lb. of malt go to the sack, one-sixth going into the sponge. As in England, strong flours are used for the sponge, but rather stronger flours are used for the dough than is usual in England. Scottish loaves are largely of the "brick" type, high and narrow. Such bread has an attractive appearance and keeps well. It has a rather sharp flavour, approaching acidity but avoiding sourness, while the large quantity of malt used adds a characteristic taste. The yield rises in some Glasgow bread factories to 100 loaves to the sack.

Leavened bread.

In many parts of Europe bread is still made from leaven, which, properly speaking, consists of a portion of dough held over from the previous baking. This substance, known to French bakers as _levain_, is called in Germany _Sauerteig_ (_anglice_ "sour dough"). The lump of old dough, placed aside in a uniform temperature for some eight hours, swells and acquires an alcoholic odour, becoming the _levain de chef_ of the French bakers. It is then worked up with flour and water to a firm paste double its original volume, when it becomes the _levain de premiere_. Six hours later, by the addition of more flour and water its amount is again doubled, though its consistency is made rather softer, and it becomes the _levain de seconde_. Finally, by another addition of flour and water, the amount is again doubled, and the _levain de tous points_ is obtained. This mass is divided into two parts; one is baked yielding rather dark sour bread, while the other is mixed with more flour and water. This second portion is in turn halved, part is baked, and part again mixed with more flour, this last batch yielding the best and whitest bread. In North Germany leaven is generally used for making rye bread, and loaves baked from a mixture of wheat and rye flour. In the bakery of the Krupp works at Essen, each batch of the so-called Paderborn bread is prepared entirely with leaven from 270 kilos of rye flour (patent quality), 100 of wheat flour (seconds), 2 of buckwheat meal, 6 of salt, 5 of leaven, and one litre of oil. In Vienna leaven is never used for making the rolls and small goods for which that city is famous. Viennese bakers use either brewers' yeast or a ferment, prepared by themselves, of which the basis is an infusion of hops. Brewers' yeast is added to the ferment, which takes the form of a very slack dough. With 100 kilos (220.46 lb.) of flour about 17 litres or nearly 2 gallons of ferment are used.

Aerated bread.

In the original Dauglish process for the manufacture of aerated bread, which was brought into operation in Great Britain in 1859, carbonic acid gas was evolved in a generating vessel by the action of sulphuric acid on chalk, and after purification was forced at high pressure into water, which was then used for doughing the flour. In this process the flour that had to be made into bread was submitted to the action of the super-aerated water by direct transference. It was found, however, in practice that much difficulty occurred in making the gas admix readily with the flour and water, great pressure being required, and to lessen the difficulties a new process, called the "wine whey," was introduced. To carry this out, a vat placed on the upper storey of the factory is charged with a portion of malt and flour, which is mashed and allowed to ferment until a weak and slightly acid thin wine is produced; this after passing through the coolers is stored until it is transformed into a vinous whey. This whey is then introduced into a strong cylinder partly filled with water, and is aerated by letting in the gas (now stored in a highly compressed form in bottles), the pressure required being only a quarter of that necessary with the original method. The flour having been placed in the mixers, which are of globular form containing revolving arms, the aerated fluid is admitted, and in a short period the flour and fluid are completely incorporated. By means of an ingenious appliance termed a dough cock, the exact amount of dough for a single loaf of bread is forced out under the pressure of the gas, and by reversing the lever the dough, which expands as it falls into a baking tin, is cut off. Two sacks of flour can be converted with ease into 400 2-lb. loaves in forty minutes, whereas the ordinary baker's process would require about ten hours. At first a difficulty was encountered in the fact that the dough became discoloured by the action of the "wine whey" on the iron, but it was overcome by Killingworth Hedges, who discovered a non-poisonous vitreous enamel for coating the interior of the mixers, &c. It has been claimed for the Dauglish process that it saves the baker risks attendant on the production of carbon dioxide by the ordinary process of fermentation, in that he is no longer liable to have his dough spoilt by variations of temperature and other incalculable factors, the results being certain and uniform. A further claim is the saving of the proportion of starch consumed by conversion into glucose during the process of fermentation. The original objection, that, by the absence of fermentation, those subtle changes which help to produce flavour are lost, is annulled by the use of the wine whey process. The Dauglish process is well suited for producing small goods, such as cakes and scones, where flavour can be artificially imparted by means of currants, flavouring essences, &c. An undoubted advantage of the aerating process of bread-making is adaptability for utilizing flour with unstable gluten, which can thus be made into an excellent quality of bread. For wholemeal bread, too, there is probably no more suitable process than the Dauglish. The strong diastasic action of the cerealin, inevitable in fermentation, is entirely avoided. The Aerated Bread Company have about a hundred depots in London, which are supplied from a central factory.

Apostolov process.