Page images
PDF
EPUB

caramel from ordinary duty-paid sugar, and to use it for colouring their beer, but in most cases roasted malt is preferred for this purpose.

Malt loses in weight, during the process of roasting, about 10 lbs. per bushel, and increases about 6 per cent. in bulk, while barley treated similarly, loses about 12 lbs. per bushel, and increases in bulk from about 14 to 22 per cent, and may, by peculiar management in roasting, be increased even to upwards of 30 per cent. This difference depends chiefly on the degree of rapidity of roasting, as the following table will show.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][ocr errors]

As roasted malt is sold by measure, a glance at this table will show the great inducement which the roaster has to practise the fraudulent substitution of barley for duty-paid malt, although roasted barley is not nearly so well adapted as roasted malt for the colouring of beer ; but since the two are, to an ordinary observer, almost identical in appearance, the necessity of possessing an easy and certain mode of discrimination between them is obvious.

To distinguish between Malt and Barley.-Unroasted malt may be easily distinguished from unroasted barley, by the circumstance that in a grain of malt, the end from which the rootlets have protruded, remains open and thus presents a marked distinction of appearance to the closed end of a barley-corn. The husk of barley, also, has numerous wrinkles, from which the husk of malt is generally free.

If some of the suspected grains be boiled, for a few minutes, in water, or in a dilute solution of potash, or common washing soda, the difference between malt and barley will be more apparent. The husk will have become somewhat transparent, so as to permit the outline of the acrospire to be discerned through it ; and if germination has taken place, to the smallest extent, the remains of the rootlets will be seen to protrude from the opening at the base of the grain.

Malt when roasted preserves all its characteristic appearances, and may with a little care, be readily distinguished from roasted barley. The latter is shorter, thicker, and less liable to fall in pieces, and its wrinkled appearance is not altered.

As a series of accurate drawings, showing the difference between a grain of roasted and unroasted malt and one of barley, is furnished for the guidance of officers in the Instructions relative to Licences, &c., it has been judged unnecessary to insert similar illustrations in the present work.

BEER BREWING. Wort is the technical name of the liquid obtained by dissolving sugar in water, or by extracting the soluble portion of malt and other sugar-yielding substances in the process of brewing. Malt wort is found on analysis, to consist of variable proportions of starch, sugar, gum or dextrin, gluten, and albumen, together with phosphates and other salts. It is prepared by bruising or crushing the malt into a coarse meal, and digesting this for a sufficient time in water at a heat of from 158° to 170° F. Cane-sugar wort is simply a solution of raw sugar containing the usual impurities present in that substance.

In the manufacture of beer, which can only be prepared legally by public brewers from malt or sugar, the following operations take place successively, namely, grinding, mashing, boiling, cooling, fermenting, cleansing, fining, and racking.

Grinding or Crushing.-In order to prevent brewers from using raw grain, a practice which would lessen the revenue derived from malt, it is enacted that malt shall only be bruised or crushed by smooth metal rollers and not ground between stones. This restriction has been imposed with the object of facilitating the microscopical examination of the meal prepared for mashing. The action of plain rollers, set close together, is sufficient to flatten or bruise the grains of malt without reducing them to powder or entirely breaking up their structure. But raw corn when so treated, although it becomes flattened with difficulty, retains so much of its natural cohesion, that it is possible to distinguish it in that state from corn which has undergone germination, whereas when ground between mill-stones, or cut and torn in a steel mill, all power of tracing its identity is lost. Besides, the restriction in question is not at all prejudicial to the success of brewers' operations, since it is found that malt ground between stones, &c., is more apt to “set” in the mash tun and does not allow the mash liquor to run off so freely. By the action of rollers the substance of the grain, already made friable by malting, is completely disintegrated, while yet the parts adhere with sufficient force to prevent them from falling into fine powder or flour. The malt after being crushed is usually left in a heap for a day or two so that it may become mellow by the absorption of moisture from the air, and thus be rendered the less liable to form into lumps when mixed with hot water.

Mashing. The crushed malt is now thrown into the mash tun, and water added at a temperature varying from 158° to 170° F. according to the season, the quality of the malt, and the nature of the beer to be brewed. By some brewers the heated water is first introduced into the mash-tun, and the malt then gradually added. The contents of the vessel are stirred for half-an-hour or longer either by men with “ mashing oars," or by machinery, after which the mass is left to repose for two or three hours, the air being carefully excluded by a cover, when the liquid portion is strained off through finely perforated plates in the bottom of the mash-tun into the underback, and pumped without loss of time into the copper.

In mashing, the aim of the brewer is, not only to dissolve the ready formed sugar of the malt, but also to cause the diastase to act on and saccharify the starch in the malt. When the heat of the mash liquor stands below 140° F., very little change takes place beyond the dissolving out of the ready-formed sugar and gum, as at that temperature the diastase and gluten are unable to act with effect on the starch, the worts rarely clarify, and as a consequence, the matured beer is liable to become acid. Again, at a heat exceeding 180° F. the granules of starch burst and form a gelatinous mass through which the water cannot percolate, and on which the diastase and gluten have little action. A medium temperature of 150° F. is found to be that most suitable for the mashing process, and below 145° F. the heat of the mash should never be allowed to fall. After drawing off the first wort the residue in the mash-tun is either mashed with more water at a temperature about 10° higher than at first, or it is « sparged,” that is, sprinkled with water at 180° F. to wash out the remaining soluble matter. Whichever plan be adopted, the second extract is either added to the first in the copper, or made into weak beer. Frequently a third and even a fourth extract is taken and made into table beer, or else is concentrated by boiling and roserved for a future mashing.

Boiling. -- As soon as the wort is collected in the copper, a quantity of hops varying from 4 to 20lbs. per quarter of malt mashed, is added, and the whole boiled for two or three hours. The object of boiling is to concentrate the wort, expel the air contained in it, coagulato and throw down the excess of the albuminous substances present, and to enable the liquor to extract the aromatic oil and bitter principle of the hops. It is necessary to get rid, as much as possible, of any excess of albumen and mucilage, as these substances favor the development of acid in the finished beer, and thus injure its keeping quality.

Cooling.–When sufficiently boiled, the wort is strained from the hops, rapidly cooled in shallow vessels or refrigerating pipes down to a temperature compatible with the commencement of fermentation, and is then let into the fermenting tuns. It is requisite to cool the worts with the utmost attainable dispatch, so as to prevent the formation of any appreciable amount of acid, which is certain to take place if the worts are long exposed at a high temperature to the atmosphere. Indeed, the most effective methods of cooling will not prevent the worts from becoming slightly acid.

Fermentation.-Fermentation is undoubtedly the most delicate operation of the brewer, as it is that, on the management of which the quality and condition of his beer chiefly depend. The temperature at which the wort is set to ferment varies according to the season, and the gravity and quantity of the wort, but ordinarily, it ranges from 54° Fah. to 68° Fah. The quantity of yeast to be used depends on its freshness, the rapidity with which it is desired that fermentation should proceed, and also on the degree of attenuation considered necessary. In general, about 1 per cent. is at first added, and more subsequently if the fermentation flags. In about five hours after the addition of the yeast, fermentation begins, and continues for four or five days. The yeast is then skimmed off, and the beer run into a number of smaller vessels or casks, in order to cleanse it. It is not the interest of the brewer, as it is of the distiller, to decompose all the sugar in the wort, but to leave some of it to give body to the beer, and keep up the evolution of carbonic acid and the production of alcohol.*

Cleansing.–The object of the process of cleansing is to free the beer from undissolved matter, remove the fresh yeast as it is formed, lower the temperature, and check fermentation. The cleansing-casks are kept full by adding properly

* A further account of the naturo and properties of yeast, and of the theory of fermentation, will be given in the article on the Manufacture of Spirit.

matured beer to them, the yeast as it rises to the surface being conveyed away by a trough. When sufficiently clear and bright, the beer is run into store rats for future use, or racked into casks, and either stored or sent at once into consumption. From bad fermentation or other circumstances, it frequently will not clear in the cleansing casks, and to fine it, a little isinglass dissolved in sour beer is added. This substance either mechanically unites with the particles of yeast and albumen, which then fall to the bottom, or some of it combines with the tannin of the hop, and precipitates, carrying with it the suspended matter.

Finished beer varies in specific gravity from 1004° to 1030°, and contains from 8 to 19 per cent. of proof spirit, together with undecomposed sugar, gum, colouring and extractive matter, and various salts.

On an average, 4 barrels of beer at 1054o are procured froin 8 bushels of pale malt.

Pale ale, bitter beer, and porter are manufactured in the manner just described only, in each, there is a slight variation in the quality and character of the malt and hops used, and also in the extent of attenuation, &c.; thus, pale ale is made from the finest pale malt and the best hops, and attenuated to a low gravity, while bitter beer is prepared in a similar manner with an excess of hops. Porter is brewed from varying quantities of pale, amber, and brown malt, together with a slight addition of roasted malt or caramel, to bring up the colour.

The adulterations of beer will be treated of in a subsequent part of this chapter.

MANUFACTURE OF SPIRIT. The process of the manufacture of British spirits is so fully and plainly described, as regards all its essential details and principles, in the tract appended to the Instructions for Surveying Distilleries, a copy of which is accessible to every officer, as to render it needless to devote more than a small portion of the present article to a consideration of the general theory of the subject. It appears desirable. however, to supply a few additional particulars connected with the purely practical or mechanical parts of the distiller's operations, and especially to give a minute account of the structure and mode of action of Coffey's patent still. The magnitude and seeming complexity of this ingenious contrivance prove a source of bewilderment to most officers on their first experience of a distillery where one is used ; and it cannot be doubted that a familiar knowledge of the interior of the apparatus, as well as of the object of each of its numerous pipes and the course of the liquids or vapours passing through it, must greatly enhance the efficiency of those who are engaged in the responsible business of securing the duty on home-made spirits.

SUMMARY OF CHEMICAL AND TECHNICAL FACTS RELATING TO THE

FABRICATION OF SPIRITS. In common language, the term Alcohol is applied exclusively to one kind of spiritthat obtained by the distillation of a fermented saccharine liquid, and which forms the characteristic ingredient of whiskey, rum, brandy, and other spirituous beverages. For the purposes of every-day life it is perhaps convenient to limit the designation in this way, but it is useful and instructive to know that chemists give the general name, alcohol, to a class of bodies belonging to the same type or constituted on the same principle, and possessing certain properties and qualities similar to those of ordinary alcohol.

Wood naphtha, for instance, is, chemically considered, a species of alcohol. Fusel or Fousel oil—that which collects on the surface of distillers' feints-- is also classed as an alcohol. There are several other members of the family of alcohols, each bearing å title suggestive of its origin or its composition, but none of these has as yet found any application in the arts, or presented itself out of the domain of scientific research. The three well-known varieties above mentioned are named and distinguished as follows :

Ethylic or Vinous Alcohol, the basis of spirits of wine, whiskey, rum, &c.; the intoxicating element in wine, beer, and other fermented liquors ; is a colourless, limpid, and exceedingly volatile liquid, having a pungent bat agreeable taste and odour ; has the density of •79385 at 60° Fah.; boils at 173° Fah.; is highly inflammable, and burns without smoke unless the supply of air be deficient; mixes with water in all proportions ;, dissolves a great number of resins, oils, and other substances,

Methylic or Pyroxylic Alcohol, the basis of wood spirit or wood naphtha, obtained by the destructive distillation of hard woods ; is a thin, colourless, volatile liquid, of peculiar and unpleasant odour, and of a burning, nauseous taste ; has the density of .798 at 60° Fah.; boils at 150° Fah.; is very inflammable, even more 80 than vinous alcohol, and burns with a palo flame free from smoke; mixes with water in all proportions ; has solvent powers almost equal to those of vinous alcohol, &c.

Amylic Alcohol, the basis of the so-called fusel oil, or oil of grain spirit, contained in distiller's feints ; is a thin, transparent fluid, exhaling a powerful persistent, and suffocating odour; has a hot, acrid flavour, and acts most injuriously on the system; density at 60o=8184 ; boiling point=270° ; does not readily ignite, but when warmed and set fire to, burns steadily with a bluish white flame. Is not miscible, except in a very slight degree with water ; is to some extent useful as a solvent, but is not comparable in this respect to either ethylic or methylic alcohol.

All the distinctive qualities mentioned in the preceding description have reference to the alcohols only when the latter are in a state of purity and concentration. If these be in any degree diluted or impure, each of their characteristics will be modified to a greater or loss extent, according to the nature and quantity of the foreign substances present.

Without entering formally into a statement of the elementary constituents of the different alcohols, or of their atomic relation to one another, it will convey to the general reader a sufficiently precise idea of the theory of the subject, to be told that these bodies have been accurately analysed, and that they have all been found to agree in two leading particulars, viz.,-1st, that they consist of the same elements, carbon, hydrogen, and oxygen, the proportions of the first two differing by a very simple ratio in each body, whüe the amount of oxygen is the same in all ; and 2nd, that they give rise, on being appropriately treated, to a series of ethers and acids which exhibit a relation similar to that of the bodies themselves ; thus, on an abstraction of the elements of water-1 equivalent of hydrogen and 1 of oxygen--from each of them successively, which can be effected by the contact of acids at a high temperature, ethylic alcohol is converted into common ether (sulphuric ether); and methylic and amylic alcohol into methylic or wood spirit ether, and amylic ether respectively. Also, by the substitution of two atoms of oxygen for two of hydrogen, ethylic alcohol is converted into acetic acid, the basis of vinegar; methylic alcohol into formic acid,

« PreviousContinue »