661 



DISTILLERY. 



DISTILLERY. 



602 



greater part of it falls to the bottom on account of its density relatively 

 to the subjacent fluid. In from forty-eight to sixty hours the liquor 

 begins to grow clear, and becomes comparatively tranquil. It has 

 been deemed advantageous towards the perfection of the fermentation 

 to rouse up the wash occasionally with a proper stirrer, and in some 

 cases to increase its temperature a few degrees by the transmission ol 

 steam through a serpentine pipe coiled round the sides of the vat 

 Some have imagined that a considerable portion of spirit is carried of 

 by the great volume of carbonic acid evolved, and have proposed to 

 save it by covering the vats air-tight, and conducting the gas through 

 a pipe in the lids into a vessel containing water. The economy of this 

 apparatus is not worth the expense and trouble which it occasions. 

 The distillers content themselves with enclosing their vats after the 

 first violence of the action under tolerably tight covers. It is found 

 that the acetous fermentation is always proceeding simultaneously 

 with the vinous fermentation : for judging by the usual tests there is 

 always a slight degree of acidity in fermenting wash ; that vinegar is 

 in fact forming along with alcohol, or that while the attenuation is 

 increasing, acetic acid is being formed. This important fact serves to 

 show how very fallacious a test the attenuation or diminution of 

 density is of the amount of alcohol generated and existing in 

 fermented wash. The acetic acid along with the undecomposed 

 mucilaginous starch may, in fact, so far counteract the attenuating 

 effect of the spirits as to produce a specific gravity which shall indicate 

 10 or 15 per cent, less spirit than is actually present in the wash. 



It is computed that every 5 degrees of attenuation, as it is called, 

 that is every diminution of the number 5 upon the specific gravity in 

 the third place of decimals, ought to produce 1 per cent, of proof 

 spirit, or 1 gallon out of 100 ; so that if the wort be set at V055, and 

 come down to 1*000, 11 gallons of proof spirits are chargeable upon 

 each 100 of such wash. In the fermentation of sugar worts, 1 gallon 

 of proof spirits was calculated for every four degrees of attenuation ; 

 but distillation from sugar or molasses-wash is now illegal. With 

 oorn-waah there is never more than four-fiftha of the saccharine 

 matter decomposed into alcohol and carbonic acid, in the best-managed 

 fermentation, and frequently indeed much less. In fact, each pound 

 of real sugar may be resolved by a successful process into half a pound 

 of alcohol, or into about one pound of proof spirit ; and hence as a 

 solution of sugar at the density of 1'060 contains 15 per cent, by 

 weight, or 16 per cent, by measure, which is nearly 1'7 pounds per 

 gallon, it should yield nearly 170 pounds from 100 gallons, or 180 

 pounds measure equal to 18. gallons of proof spirit ; whereas 100 gallons 

 of corn-wash, fermented at the above density, are computed by the 

 excise law to yield only 12 gallons, and seldom produce more than 13 

 and a small fraction. 



In the huge fermenting vats used by the corn distillers of this 

 country, the fermentation goes on far more slowly than when con- 

 ducted upon the moderate scale referred to in the account of this 

 process given above. About 1 gallon of yeast is added at first for 

 every 100 gallons of wort, and a half gallon additional upon each of 

 the succeeding four days, making in the whole 3 per cent, ; when less 

 can be made to suffice, the spirits will be better flavoured. The fer- 

 mentation goes on during from six to twelve days, according to the 

 modifying influence of the circumstances above enumerated. After 

 the fifth or sixth day, the tuns are covered in, so as to obstruct, in a 

 certain degree, the discharge of the carbonic acid : since it is supposed 

 that this gas in excess favours fermentation. The temjieraUire is 

 usually greatest on the fourth or fifth day, when it sometimes rises to 

 85 Fahr., from the starting pitch of 60 or 50. Whenever the 

 attenuation has reached the lowest point by the hydrometer, the wash 

 ought to be distilled, since immediately afterwards the alcohol begins 

 to be converted into acetic acid. This acidification may be partially 

 repressed by the exclusion of atmospheric oxygen. 



III. DittiUatim. There are few kinds of chemical apparatus which 

 have undergone so many metamorphoses as the still and condenser. 

 In its simplest form it has been already represented and described. 

 [ALEMBIC.] It may be considered to have reached its highest point of 

 perfection, as to power and rapidity of work in Scotland, at the time 

 when the distillers paid a stipulated sum per annum to the revenue 

 for the privilege of using a still of a certain size, and when therefore 

 they derived a profit proportionable to the quantity of spirits they 

 could run off' In a given time. Since the year 1 815, the whiskey duties 

 have been levied on the quantity distilled, independent of the capacity 

 of the still. This change has introduced a modification in the distilling 

 ap|>aratus, with the view of combining purity of product with economy 

 of time. The body of the still is still comparatively flat, so as to 

 expose a large surface to the fire ; but the tapering upper part, cor- 

 responding to the capital of an alembic, is made very loug, rising 

 sometimes 15 or 20 feet before it terminates in the worm pipe or 

 refrigeratory for condensation. 



Great distilleries are usually mounted with two stills, a larger and a 

 smaller. The former is the icaih still, and serves to distil from the 

 fermented worts a weak crude spirit called low winei ; the latter is the 

 low-iyne still, and rectifies by a second process the product of the first 

 distillation. The annexed cut represents a copper wash-still, having a 

 capacity of about 20,000 gallons. In these successive distillations a 

 ciuantity of fetid oil, derived from the corn, comes over along with the 

 fit stand last portions received, and constitutes by its combination what 



AHTS \yu SCI. DIV. VOL. III. 



is styled, in the language of the distilleries, the strong and weak fai n ts. 

 These milky faints are carefully separated from the limpid spirit by 

 turning them as they begin to flow from the worm-end into distinct 



Wash Still. 



channels, which lead to separate receivers. From these receivers the 

 various qualities of spirit, low wines, and faints, are, for the purpose 

 of redistillation, pumped up into charging backs, from which they are 

 run in gauged quantities into the low-wine and spirit stills. 



One of the greatest improvements in modern distillation is the 

 accomplishment of this essential analysis of the impure spirit at one 

 operation. Chemistry had been long familiar with the pneumatic 

 apparatus of Woulfe, without thinking of its adaptation to distillery 

 apparatus ; when Edouard Adam, an illiterate operative, after attending 

 by accident a chemical lecture at Montpellier, where he saw that appa- 

 ratus, immediately employed it for obtaining fine brandy, of any 

 desired strength, at one and the same heat. He obtained a patent 

 for this invention in July, 1801, and soon afterwards was enabled by 

 his success to set up in that city a magnificent distillery, which attracted 

 the admiration of all the practical chemists of the day. In November, 

 1805, he obtained a certificate of improvements whereby he could 

 extract from wine at one process the whole of its alcohol. Adam waj 

 so overjoyed after making his first experiments, that, like another 

 Archimedes, he ran about the streets telling everybody of the sur- 

 prising results of his new invention. About the same time, Solimani, 

 professor of chemistry at Montpellier, and Isaac Berard, distiller in the 

 department of Gard, having contrived two distinct systems of appa- 

 ratus, each most ingenious, and obtaining results little inferior to 

 those of Adam, became in consequence formidable rivals of his fame 

 and fortune. 



The late Dr. Ure devised a form of distilling apparatus which to him 

 appeared to combine the delicacy of the French with the solidity of 

 the English forms. The lower the temperature of the spirituous 

 vapour which enters into the refrigerator, the stronger and finer will 

 the condensed spirit be ; because the noxious oils are less volatile than 

 alcohol, and come over chiefly with the aqueous vapour. A perfect 

 still should therefore, he believed, consist of three parts : first, the 

 cucurbit or boiler ; second, the rectifier, for intercepting the greater 

 part of the watery particles, and the whole of the corn oil ; and third, 

 the refrigerator. Three principal objects are obtained by this aixange- 

 ment : first, the extraction from fermented wort or wine, at one 

 operation, of a spirit of any desired cleanness and strength ; second, a 

 jreat economy of time, labour, and fuel ; third, freedom from all 

 danger of blowing up or boiling over by mismanaged firing. When a 

 mixture of the alcohol, water, and essential oil, in the state of vapour, 

 is passed upwards through a series of winding passages, maintained at 

 a regulated degree of heat, from 1 70 to 180, the alcohol aloun, in 

 notable proportion, retains the elastic form, and proceeds onward into 

 the refrigeratory tube, in which these passages terminate; while the 

 water and the oU are, in a great measure, condensed and retained in 

 the passages, so as to drop back into the body of the still, and be 

 discharged with the effete residuum. 



The system of channels shown in fy. 2 is so contrived as to bring 

 the compound vapours which rise from the alembic A into intimate 

 md extensive contact with metallic surfaces, immersed in a water-bath, 

 md maintained at any desired temperature by a self-regulating ther- 

 mostat or heat-governor. The neck of the alembic tapers upwards as 

 hown at B, fy. 1 ; and at c, fy. 1, it enters the bottom or ingress 



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