Ferment

“ Whether the fermentation proceeds from germs taken from the exterior surface of the grapes, or from a small quantity of ferment sown in the must under the form of yeast, as in the fermentation of beer, the life of the ferment, its multiplication, the augmentation of its weight, are so many vital actions which to a certainty cannot borrow from the free oxygen of the external air, or from that originally dissolved in the must, an appreciable quantity of this gas. All the life of the cells of the ferment which multiplies itself indefinitely appears then to take place apart from free oxygen gas. ”

“ It being a disputed point whether the vinous fermentation would take place, in worts or wash, when the air is excluded, without any addition of yeast or other ferment, we shall here introduce minutes of an experiment, which was made under our notice, and which appears very conclusive. ”

“ I have seen some supercilious men that would not add ferment to the matter of their spirit, but sugar or honey, by which they would promote fermentation, and so have thought to get a pure spirit, not considering that honey and sugar, after fermentation are made to yield their spirit also, whereof one spoonful yields more than ten or twenty of Barm: But hony and sugar fermenting not without difficulty themselves, how can they promote the fermentation of other things? ”

“ There are indeed the fruits of some trees that have a sweet and full juice, as grapes, cherries, apples, pears, figs, &c. which need not the addition of any ferment, having a natural ferment of their own, but other vegetables not so, being lean, as hearbs, flowers and roots. It is necessary there to promote the fermentation of them by the addition of a sutable ferment, lest in length of time these hearbs and seeds lose their spirit exhaling in maceration. ”

“ Fermentation is the process by which, under influence of air, warmth, moisture, and some ferment, sugar (or dextrose, starch converted into sugar) is changed into alcohol (C2H5HO) and carbon dioxide (CO2) . The product of all fermentation is the same. Three kinds are considered,—alcoholic, acetic, and lactic. Where bread dough is allowed to ferment by addition of yeast, the fermentation is alcoholic; where alcoholic fermentation continues too long, acetic fermentation sets in, which is a continuation of alcoholic. Lactic fermentation is fermentation which takes place when milk sours. ”

“ In that work we established for the first time that the lactic ferment is a living, organized being, that albuminous substances have no share in the production of fermentation, and that they only serve as the food of the ferment. M. Bechamp's note was even subsequent to our first work on alcoholic fermentation, which appeared on December 21st, 1857. It is since the appearance of these two works of ours that the preponderating influence of the life of microscopic organism in the phenomena of fermentation has been better understood. ”

“ A ferment is a substance containing nitrogen in a state of decomposition, which is able to excite fermentation in solutions of sugar; old cheese, putrefying flesh, blood, etc., all of them are ferments.
What is yeast?
We apply the term yeast to a particular species of ferment; the foam of beer (or of some similar liquor) , produced by fermentation.
Can you explain why it is that a body in a state of fermentation or putrefaction should cause unlimited quantities of similar matter to pass into the same state?
We only know the fact: the reason we are ignorant of. ”

“ More recently the conception of the living cell as the essential feature of the process has been dethroned in its turn, and alcoholic fermentation is now shown to rest on the action of an 'unorganized,' 'lifeless,' or 'soluble' ferment or enzyme, secreted by the yeast plant. Further, the action of this enzyme and of other and more familiar 'unorganized' ferments has been brought into line with some of the most characteristic activities of the living cell, and many general life phenomena have been shown to be in reality phenomena of fermentation. ”

“ Under suitable conditions they multiply rapidly, deriving the energy for their life processes from the chemical changes which they induce. For example, in the souring of milk the milk sugar is changed by the lactic acid ferments into lactic acid. In causing chemical changes, the ferment gives none of its own material to the reacting substance. These ferment bodies undergo life processes similar to plants of a higher order. ”

“ But this latter ferment is no less of organic origin; it, too, arises from living beings, animal or vegetable. Whether it emanates, like diastase, from the young cells of the seed, or results, like pepsin, from work done in the digestive apparatus, it is the labor of life, just as much as if it had been completed by globules of yeast or bundles of bacteria. Thus the efficient sources of all fermentations are the same. All ferments are at bottom alike, whether procured directly for the fermentable liquid by microscopic bodies inhabiting it, or emanating from corpuscles that inhabit elsewhere. ”

“ Let us compare the action of ferment or yeast in a dried state to the action of albumen, which Liebig says is sufficient when decomposing to set up fermentation. "The white of eggs when added to saccharine liquors requires a period of three weeks, with a temperature of 96° F. before it will excite fermentation." [42] But any saccharine liquor on exposure to the air, though entirely destitute of albumen or gluten, will ferment, and the Torula may be found in it. I have found the Torula in a great variety of syrups which have spontaneously undergone fermentation. ”

“ We see many Tracts of Land, which yield peculiar Ferments, sometimes Vitriolate Earth, sometimes Aluminous, sometimes Nitrous, sometimes common-Saline, healing Bolus's, and Earth proper for Fullers, Tobacco-pipes, &c. Sometimes the ferment is so hot, as to hollow the surface faster than can easily be allay'd by Mixtures of a more sullen soyl. ”

“ We may imagine that a ferment is directed against a simpler product of decomposition, and yet that it attacks at the same time a more complicated molecule, in so far as the group through which it attacks the substrate is actually present therein and within reach. ”

“ Our knowledge of the facts detailed in the preceding chapter concerning pure ferments, and their manipulation in the presence of pure air, enables us completely to disregard those causes of embarrassment that result from the fortuitous occurrence of the germs of organisms different in character from the ferments introduced by the air or from the sides of vessels, or even by the ferment itself. ”

“ This heat, indispensable to the phenomena which observation detects, is furnished by the decomposition of sugar. The position is the same as in the case of the decomposition of sugar in the presence of yeast-cells living without air. This decomposition of the sugar is manifested in the fruit by the production of alcohol and of carbonic acid. Here the ferment is the cell of the parenchyma of the fruit. There is in this cell a life kept up, or a chemical process accomplished, without air; according to our theory, fermentation should be present there, and experiment shows that it is. ”

“ Fermentative Agents.—Fermentation in vegetable matter is always accompanied by the growth of living organisms. The development of these minute organisms is the exciting cause of fermentation and putrefaction. The germs or spores of some of these fermenting agents are always present in the air. It is well known to housekeepers that if a batter of flour and water and a little salt be kept in a jar of water at a temperature of from 100° to 110°, it will ferment in the course of five or six hours. ”

“ When other circumstances are the same, the rapidity of the fermentation is proportional to the temperature within certain limits, so that by lowering it, the action may be moderated at pleasure. 3. The fermentation proceeds the better and more equably the greater the mass of fermenting liquor, probably on account of the uniformly high temperature, as well as the uniform distribution of the active particles of the yeast by the greater energy of the intestine movements. 4. The saccharine solution must be sufficiently diluted with water; when too much concentrated it will not ferment. ”

“ Cooked food favors bacterial, or organized, ferment preponderance, because cooking kills the unorganized and organized ferments, and both are needed to carry on the body's digestion. Raw foods--fruits and vegetables--favor unorganized ferment digestion, because these foods carry vitamins, which are unorganized ferments--enzymes. ”

“ Our knowledge, as yet, is quite meager, but enough has already been determined to indicate that the whole industry is largely based on the phenomena of ferment action, and that the application of bacteriological principles and ideas is sure to yield more than ordinary results, in explaining, in a rational way, the reasons underlying many of the processes to be observed in this industry. ”

“ As a specimen of the writer's humor, his account of what happens when fermentation comes to an end may suffice: "When the animals find no longer any sugar, they devour one another; and this they do in a peculiar manner. They digest the entire animal, excepting only the eggs, which pass through the intestinal canal unchanged, and so the residuum is still a fermentable substance, viz., the sperm of the animals, which remains over." ”

“ In the experiments which we have described, fermentation by yeast, that is to say, by the type of ferments properly so called, is presented to us, in a word, as the direct consequence of the processes of nutrition, assimilation and life, when these are carried on without the agency of free oxygen. The heat required in the accomplishment of that work must necessarily have been borrowed from the decomposition of the fermentable matter, that is from the saccharine substance which, like other unstable substances, liberates heat in undergoing decomposition. ”

“ In both spontaneous and excited fermentation, there is a similar escape of a large quantity of elastic fluid, or carbonic acid gas, with a considerable proportion of spirit, and some of the water of the fermented fluid. This gas is known to form a considerable part of mucilaginous substances, as sugar, molasses, honey, malt, and other saccharine and fermentable matter.
Although the doctrine of fermentation, as a science, does not enable us to alter the spontaneous course of nature ”

“ We have admitted, in our time, that alcoholic fermentation, instead of being an exception, is on the contrary the very type of the phenomena we are treating of; that the yeast-cells, far from being unimportant, take an essential part in it, and that in all fermentations whatever there occur low organizations, microscopic corpuscles, more or less analogous to those of yeast. ”

“ Still a third species of ferment may cause another action, changing acetic acid to H2O and CO2. The vinegar then tastes flat. HC2H3O2 + 4 O = 2H2O + 2 CO2.
Some mineral acids, as H2SO4 and HCl, and some organic acids, are regarded as lifeless ferments. To this class are thought to belong the diastase of malt and the pepsin of the stomach. This variety of ferments exists in the seeds of all plants, and changes starch to glucose.
331. Bread which is raised by yeast is fermented, the object being to produce CO2, bubbles of which, with the alcohol, cause the dough to rise and make the bread light. ”

“ Fermentation now includes all changes in organic compounds brought about by ferments elaborated in the living animal or vegetable cell. There are two distinct types of fermentation: (1) those brought about by living organisms (organized ferments) , and (2) those brought about by non-living or unorganized ferments (enzymes) . The first class include such changes as the alcoholic fermentation of sugar solutions, the acetic acid fermentation of alcohol, the lactic acid fermentation of milk sugar, and the putrefaction of animal and vegetable nitrogenous matter. ”

“ To conclude, fermentations occasioned in certain media, by the act of development and nutrition of ascertained microscopic animal or vegetable existences, present a group of well-defined characteristics. They follow obediently all the variations that may occur in the physiological activity of the microscopic beings contained in the liquid. This does not go into fermentation all at once; it delays more or less, and molecular movement makes itself perceptible in it by degrees. The phenomenon is one of evolvement. ”

“ When flour made into dough is kept for some time moderately warm, it undergoes spontaneous fermentation, formerly described as ‘panary fermentation,’ and supposed to be of a different nature from the fermentation which produces yeast. ”

“ Spirituous fermentation is that process of fermentation by which forms of yeast cells, by their growth and reproduction in such complex substances as grapes, fruit, apple juice, grains, etc., extract alcohol from these substances and by this process produce wine, cider, spirits, etc. ”

“ The making of beers, wines, and spirits, as we understand them, 386 constitutes but a small part of the province of fermentation. The life activities of ferments open out a study of vast importance to mankind, and while they have only been regarded in their worst aspect—that of a bane—they are, nevertheless, a boon to mankind. The first clear view we obtained of this was that of Reess, who in 1870 showed there were several species or forms of the yeast-fungus. ”

“ It is true that the chemical changes induced by organised ferments depend on the life processes of micro-organisms which feed upon the sugar or other substance in solution, and excrete the product of the fermentation. Fermentation nearly always consists of a process of breaking down of complex bodies, like sugar, into simpler ones, like alcohol and carbonic acid. Of such fermentation we may mention at least five: the alcoholic, by which alcohol is produced; the acetous, by which wine absorbs oxygen from the air and becomes vinegar; the lactic, which sours milk ”