New bags may, indeed, be placed in the same liquor for three or four successive fermentations without adding further yeast or juice.
In these the molasses is mixed with spent wash from other fermentationsor with water, after which it is acidified and flows to the fermenting vats.
Unfortunately, from one cause or another, faulty fermentations and changes are not infrequently set up.
Each of these will be referred to as they occur in considering the five important fermentations already mentioned.
We are now in a position to consider particular fermentations and their causal micro-organisms.
From these words we gather that there is no one particular organism or vegetable cell to be designated the micro-organism of fermentation, but that there are a number of fermentations each started by some specific form of agent.
Secondly, there are special fermentations and modifications of yeast fermentation due to bacteria.
To each species of wild yeast there belongs some taint-producing power in the fermentations for which it is responsible.
Butyric acid is a common ingredient in old milk and butter, and its production by bacteria is historically one of the first bacterial fermentations understood.
We must now mention several fermentations about which little is known.
Not only have the causal agents of various fermentations been isolated and studied, but from their study practical results follow.
If a sample of milk is allowed to stand, it will undergo a certain sequence of fermentations that well illustrates the principle that one type of organisms is dependent on some other type to furnish suitable conditions for its development.
Not all abnormal fermentations are able, though, to compete with the lactic acid bacteria, and hence outbreaks of this sort soon die out by the re-establishment of more normal conditions.
The milk from animals on low land is more likely to show undesirablefermentations than that from those grazing on higher lands.
From what has been said with reference to the abnormal fermentations of cheese, it will be seen that they are always due to the lack of acid-forming bacteria, or to their partial replacement by other types.
There are a number of other abnormal fermentations in milk that occur so rarely as to be of but little economic importance.
Unless the cheese is made from the best quality of milk, it is likely to undergo undesirable fermentations when ripened at high temperatures.
Many of these abnormal fermentations have been studied and the organisms concerned in the changes found.
Bacteria concerned in gassyfermentations and those capable of producing obnoxious taints are particularly common, so that this type of pollution is especially undesirable in milk.
The process of pasteurization was first used by the French bacteriologist, Pasteur, for the treatment of the wines of his native district which were likely to undergo undesirable types of fermentations due to bacteria.
If "gassy" fermentations occur, it signifies an abnormal condition.
The souring of milk, the rotting of eggs, the spoiling of meats, the making of vinegar from cider are examples of fermentations caused by different bacteria.
Butyric acid fermentations are more common in old butter and cheese.
If not enough salt is used, the cheese may cure too rapidly and undesirable flavors and fermentations develop.
A product which has many small pin-holes due to gassy fermentations is called a "niszler"; this means a cheese with a thousand eyes.
This produces very sour cheese with much more danger of other fermentations which cause objectionable flavor.
Normally the acid fermentation takes place first, and later other fermentations or changes begin, which, after a time, so decompose the milk that it will not be suitable for cheese-making or human consumption.
It is handled without special care since the water-content is so low that fermentations are exceedingly slow.
Gas-forming fermentations are very bad in this variety of cheese as they cannot be controlled and give the cheese a bad flavor and a "gassy body.
Proper ripening places the acid fermentations under the control of the cheese-maker so that he may know what results will follow his labors.
Hence it appears, that the spirituous and acetous fermentations are only preparatives, which nature makes use of, for bringing certain vegetable matters to putrefaction.
These fermentations therefore must be considered as advances towards that putrefaction, in which they terminate, or rather as the first stages of putrefaction itself.
Fermentations of this class are purely chemical reactions, in which the ferment acts as a simple catalytic agent.
Ferments of the first class are as a rule simple microscopic vegetable organisms, and the fermentations which they engender are due to their growth and development; as, the acetic ferment, the butyric ferment, etc.
Defn: One of a physiological group of globular bacteria which produces fermentations of diverse nature; -- distinguished from pathogene.
All these fermentations of division, rivalry, and resentment, boiled over in the April sittings.
The constitutional party desired it, in order to divert internal anarchy, and dispel those fermentations of agitation which threatened the throne.
His studies in fermentations and in silkworm diseases had taught him the use of the microscope for such investigations.
In all of these fermentations the bacteria are utilizing the carbon both as building material and for oxidation and the fermentations are incidental to this use.
In hematuria from anemia (watery blood), whether from insufficient or badly adjusted rations or from the poisonous products of fermentations in impervious or marshy soils, the treatment must be essentially tonic and stimulating.
In consequence of this, abnormal fermentations arise, causing indigestion and irritation of the digestive organs.
The irritant products of the intestinal fermentations may, however, irritate and excoriate the skin around the anus, which becomes red, raw, and broken out in sores for some distance.
It is very probable that numerous symbiotic fermentations in the soil are due to this co-operation of oxygen-protecting species with anaerobic ones, e.
The gases consist of carbonic acid, sulphuretted hydrogen, hydrogen, nitrogen, and the hydrocarbons, the butyric and acetic fermentations furnishing the hydrogen and carbonic acid gas.
The oxygen and nitrogen are doubtless simply swallowed, but the carbonic acid and hydrogen are the result of abnormal fermentations in the stomach.
The accumulation of waste matter, retained in the large intestine for considerable periods, becomes a nidus for microbes which produce fermentations and putrefaction harmful to the organism.
Muntz has shown that chloroform prevents fermentations proper, but does not interfere with the action of diastase (Comptes rendus, 1875).
Pasteur explains the fact of the immense activity at the commencement of fermentations by the influence of the oxygen of the air held in solution in the liquids, at the time when the action commences.
We can readily see thatfermentations occupy a special place in the series of chemical and biological phenomena.
This, however, is by no means the case; even in those few fermentations that we have met with in which hydrogen was absent, there was no formation of butylic alcohol.
Apart from the consideration of the relation existing between the weight of fermentable substance decomposed and that of ferment produced, there is no occasion to speak of fermentations or of ferments.
It even happened that the fermentations with the perfectly pure sugar instead of being slow were very active, when compared with those which we had conducted with, the commercial sugar-candy.
Footnote: In what way are we to account for so great a difference between the two fermentations that we have just described?
If we immerse beet-roots or turnips in carbonic acid gas, we produce well-defined fermentations in those roots.
The following is a description of two of these comparative fermentations and the results they gave.
The appearance of living organised ferments had become for Pasteur the all-important question, since in all fermentations he had observed a correlation between the chemical action set up and the presence of microscopic organisms.
Fermentations and putrefactions give rise to substances which are still very complex, although they represent the products of decomposition of fermentable matters.
Divers fermentations would simultaneously take place in it.
This has rendered the making of cheese not only more uniform, but has aided in repressing abnormalfermentations particularly those that are characterized by the production of gas.
It is possible that abnormal fermentations or even contagious diseases may thus be disseminated.
These fermentationsare of most serious import in the cheese industry, as they are especially prone to develop in the manufacture of milk into certain types of cheese.
Not all abnormal fermentations are able though to compete with the lactic acid bacteria, and hence outbreaks of this sort soon die out by the re-establishment of more normal conditions.
Not infrequently these fermentationsgain the ascendency over the normal souring change, but under ordinary conditions they are held in abeyance, although this type of bacteria is always present to some extent in milk.
Their presence in a dairy is a source of much trouble, as the unsightly appearance of the milk precludes its use as food, although there is no evidence that these ropy fermentations are dangerous to health.
In Swiss cheese, which is essentially a sweet curd cheese, thesefermentations are very troublesome.
This same method is sometimes applied in dealing with certain abnormal fermentations that are apt to occur on the farm.
An interesting case of a fermentation of this class being utilized in dairying is seen in the use of "lange wei" (long or stringy whey) which is employed as a starter in Holland to control the gassy fermentations in Edam cheese.
Another method of combatting abnormal fermentations that is often fruitful, is that which rests upon the inability of one kind of bacteria to grow in the same medium in competition with certain other species.
When acidity is produced, these gassy fermentations are checked, and in good cheddar the body is so close and firm as not readily to permit of gaseous changes.
Some fermentations are doubtless attended by a less copious emission of waste gases than that which characterizes other fermentations; and some fermentations will progress in spite of a moderate amount of pressure.
The several fermentations derive their names from their principal products.
And the facts tell me simply that all true fermentations are correlative with physiological phenomena.
In long continued fermentations moreover and particularly with high concentrations of zinc chloride less alcohol is produced than is equivalent to the carbon dioxide evolved.
In the different methods of preparing snuff the fermentations take place in different ways, and sometimes the tobacco is subjected to two or three different fermentative actions.
While, then, the alcoholic fermentations are not dependent upon bacteria, the proper management of these fermentations requires a knowledge of their habits and characters.
Under these conditions the food remains moist, but nevertheless does not undergo its ordinary fermentations and putrefactions, and may be preserved for months without being ruined.
It seems certain, however, that the quality of tobacco is in large measure dependent upon the character of the fermentations that occur at different stages of the curing.
In the great part of commercial fermentations alcohol is the product desired, and alcohol, though it is sometimes produced by bacteria, is in commercial quantities produced only by yeasts.
It seems certain also that these fermentations are wholly or chiefly produced by microorganisms, and that the character of the fermentation is in large measure dependent upon the species of micro-organisms that produce it.
Butyric acid is a common ingredient in old milk and in butter, and its formation by bacteria was historically one of the first bacterial fermentations to be clearly understood.
In all cases, however, fermentations play a prominent part.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "fermentations" in a variety of sentences. We hope that you will now be able to make sentences using this word.
