The souring is next carried out either in the same or in a separate cistern by circulating hydrochloric or sulphuric acid of 2 deg.
The rest of the operations (chemicking, souring and washing) are the same as in the old process.
Tendering of the pieces, due to insufficient washing after the final souring operation, is a common defect in bleached goods.
Souring and washing follow, when the goods are again put into the alkaline and chloride bath, as before; after which they are soured, and bucked again with soda.
This is a liquid which is formed in the souring of milk.
True, milk turns sour more quickly in thundery weather than in frosty weather, because, when thunder threatens, the air is warm and the milk-souring bacteria increase more rapidly in warm weather than in cold.
Long before the activities of bacteria were connected with various phenomena, such as infectious diseases, souring of milk, etc.
Illustration: Microscopic appearance of ordinary milk, showing fat globules and bacteria which cause thesouring of milk.
Ripened Neufchatel curdled by souring and rennet together finds its basis in Neufchatel curd also but modifies the final product until the familiar flavor and texture of the unripened form are no longer recognizable.
The souring of milk is one of the most familiar cases of fermentation.
The intervening process of matting in the Cheddar group involves a combination of a souring process with the removal of whey, during which the cubes of curd become fused into semi-solid masses.
Some substance must be added to preserve the milk and to keep it from souring or coagulating.
Curdled by souringand rennet--the Neufchatel group 95 a.
For completion of the curdling andsouring process, twelve to eighteen hours are required.
The souring can be accelerated by the use of a starter, which may be added at the rate of 0.
On the small scale, curd is made by natural souring or by use of starter, heated to expel water, cooled and molded by hand into cakes two to three inches in diameter and one-half to three-quarters inch in thickness.
Cheeses in which this souring process goes on quickly, soon contain a large enough percentage of acid to check the rotting of the cheese by decay organisms.
The series curdled by souringalone begins with approximately cottage cheese curd and develops high flavors by ripening, as in "hand" cheese.
If the milk has not been handled properly, the early stages ofsouring or some other unfavorable fermentation will have developed.
As far as followed, it consists in an initial souring process followed by ripening by molds and slime organisms.
Since it is in solution, cheese retains the aliquot part of the total represented by the water-content of the cheese, plus any part of the sugar which has entered into combination with the milk solids during the souring process.
Since, as has been pointed out, bacteria cling to all dirt, the dirt that milk contains is one of the causes of souring and putrefaction of milk, and may be a cause of disease.
Curd is also formed by the souring of milk through the action of bacteria, or by adding acid directly to the milk.
These are the "curds and whey" that result, also, from the souring of milk.
If milk is used, how may the souring of the milk be prevented?
The reason for this undoubtedly lies in the fact that the boiling kills foreign germs, and thus prevents early souring or putrefaction.
This explains why clabbered milk, which contains a considerable portion of sugar changed into lactic acid by the action of souring bacteria, is especially beneficial in preventing intestinal putrefaction.
The burning of wood, the rusting of iron, the souring of milk, and the digestion of food are, in a way, all mere examples of chemical changes.
The souring of milk can be prevented by cleanliness, which renders Pasteurizing unnecessary.
The changes which milk undergoes when souringdo not render it harmful.
If the yeast is allowed to work for too long a time or the temperature is very hot, a souring of the dough may result.
This souringcan be prevented by kneading the dough thoroughly, as soon as it has risen well or doubled in bulk, or by putting it in a very hot oven to bake, when it has reached this stage.
But quite independently of these reasons, it seems to me that the souring of the land owing to excessive saturation would be much lessened were there free ventilation under the coffee trees.
This will save many buds from being killed by souring of the sap.
There is in this way no danger of the thick fleshy leaf base decaying under the wrap and souring and killing the buds.
Fuchs described the organism which is commonly called the "blue milk bacillus" in 1841 and conjectured that the souring of milk was probably bacterial in origin.
The organism which is the commonest cause of the souring of milk thrives so well in the acid medium it produces that it crowds out practically all other kinds, though its own growth is eventually stopped by too much acid.
The most difficult thing in the souring of milk is to maintain the temperature as nearly at 100 deg.
The churning is very often performed by simply rocking the skin between the knees, acidity being induced by remnants of the previous day's milk; souring of milk is induced by the same method.
The appliances for the souring of milk on the domestic scale require some consideration.
The consequent result of the increase in bacteria is the production of lactic acid, which produces the souring so familiar in milk which has been kept in the household at a high temperature.
Pure lactic cultures are added to the pasteurised milk, and the souring process is under exact control, with the result that butter of uniform flavour and quality is produced.
Vironelle Apparatus for souring milk, made by Messrs.
Others are beneficial, and are absolutely necessary for the souring of milk for making butter or cheese and for the ripening of the latter.
Besides possessing the desirable qualities already described, they answer as nurseries for the rearing of the young, and as small air-tight vessels in which the honey is preserved from souring or candying.
It will be observed that the Mather-Thompson process does away entirely with the use of lime and soda-ash in at least two boilings and the accessory souring operation.
It is considered now to be advisable to employ it, and the souring is included, as will be observed, in the continuous operation.
Mr. Thompson originally claimed that the use of carbonic acid gas rendered the employment of a mineral acid for souring unnecessary.
It may be conceded to him that circumstances had been of a souring character.
Souring as with the madder bleach, then washing well.
After the souring it is often the custom to pile the goods on to a wooden stillage, but the goods should not be left too long so piled up for they may become dry, either entirely or in parts.
The chemicing and souringis done in strong cisterns provided with a false bottom; in these the warps are allowed to remain for about two hours.
The chemicing and souring of the hanks does not call for special mention, beyond the fact that these operations are done in the same manner as warp bleaching.
The souringis done by passing the goods through an acid liquor at 2° Tw.
The souring is done in a machine constructed in the same way as a washing machine; the trough of the machine is filled with hydrochloric acid at 2° Tw.
If they are to be dyed, they must be prepared for the dye solution by "chloring," which consists of immersion in a cold solution of bleaching powder for some hours, and then souring in vitriol.
Yet care must be observed that the souring be not carried so far as to injure the food by putrefaction.
The effect of slight fermentation, or souring the food, produces the same result.
