21 Mr. J. N. Furze on Fermentation. LXXXIX. Observations on Fermentation. 1 N consequence of the practical inconveniences arising to brewers from want of control over the fermenting tuns By JOHN N. FURZE ESP. and the changes in the worts dependent upon atmospheric temperature I was led to the following experimental obser- va tions. The infusion of malt being made according to the usual practice of brewing the wort or infusion is boiled with the hops and being subsequently cooled yeast to the amount of about one pouiid by weight to the barrel of wort is added and the whole transferred to the fermenting tan The general form of a lwewer’s fermenting tun being that ofa simple open vessel 22 Mr. J. N. Furze 011 Fermentation. the worts lie exposed during their change of state without covering and with free access of air.This as is evident must expose the fermenting mass to the variations of atmo- spheric temperature which in their turn either check or hasten the operation to such an extent that the ultimate suc- cess of the brewing is endangered and not unfreqnently con- siderable loss is sustained. These disadvantages are occa- sionally avoided in some of the larger breweries by the use of fermenting tuns which are so far inclosed as to leave but sufficient space for the escape of the gaseous matters arising from the surface of the worts when the fermentation is in full vigour. Having tried the above method without finding the desired advantage to resiilt from it new measures of proceeding were taken as follows:-A circular tun was erected whose total content was 350 barrels having a door in the side capable of being made air-tight by lining its edges with coarse serge and applying screw-pressure to the centre of it.To the upper part of this tun which was fitted with windows in the top and sides to afford to the brewer an opportunity of viewing the apparent changes in the worts two India-rubber pipes were attached each of I inch internal diameter to convey away the gas generated during the process; and *in order to pre- vent external interference the ends of the pipes were immersed to the depth of about 3 inches in a vessel of water. These arrangements must not be confounded with the at- tempts of some persons both in this country and in France to condense vapours which were supposed to rise in great abundance from fermenting liquids and which are well known to have disappointed the expectations of the projectors.On two occasions when the plan of condensation was tried by me there was not any product after passing the gaseous matter through a worm three quarters of an inch diameter and 35 feet in length surrounded with water at a temperature of 54’ for R period of 36 hours on each occasion. Having arranged the improved tun as before described the gas arising from six fermentations was allowed to escape through the water in the external vessel. After the gas had thus been washed it had lost much of the pungency of smell so characteristic of the usual mode of escape and in a few days the water had so far changed that it had a strong fetid odour similar to that of waste starch liquors and certainly not that of the aroma of the hop This from the great dif- ference between the water in question and that of the same bulk which had not been so treated must have resulted from the absorption of a something passing off i n mechanical sus- Mr.J. N Furze OTJ Fermentation. 23 pension with the gas. I n order to ascertain the contents of tlie water after being charged with the gas and vapour some of it was distilled immediately after the transmission of the gas and the result was that from 36 gallons of the water so em- ployed 9 pints of alcohol were obtained of specific gravity 0.850. I t appeared on further prosecuting the matter that more could have been obtained had a larger quantity of water been used and that the action of the water on the gas de- pended for its efficacy in a great degree upon the apparatus itself.In endeavouring to realize more extended results a tub was made which contained an arrangement of three tin plates perforated with holes set one inch apart f'rorn each other through which the gas passed in small bubbles by which means the.washing of the gas was rendered more ef- fectual. In this manner 3 per cent. of rough spirit was fre- quently obtained of specific gravity 0*850 by distillation from the gas produced by one fermentation. All these distilled products were impregnated with ammonia to a considerable amount which would necessarily affect these results as is shown by tlie following.experiments. 45 gallons of water having received a charge of gas from the fernientation of 350 barrels of porter wort had a specific gravity 0*9988 and the attenuation of the worts during the period was about 1-2 Ibs. per barrel as indicated by the sac- charometer of Dring and Fage. Of this quantity 36 gallons were reduced to one-sixth part by distillation of which 16 02. by measure were again carefully rectified and reduced to 4 oz. which had a specific gravity 0965 being equal to 33 per cent. of alcohol at 0+825. I t therefore follows that the 45 gallons would have yielded 15 imperial pints at 0.965 which would equal 5 pints at 0*825 or about 1.4 per cent. of alcohol by volume. ,5 oz. of the original 45 gallons were distilled with bnryta in excess to combine with any acids that might be present and the product was redistilled with hydrochloric acid ; chlo- ride of platinum and sodium was then added and the whole carefully evaporated to dryness ; the soluble parts having been removed by alcohol left 1.9 gr.of ammonio-chloride of plati- num which indicates by calculation 0- 146 grain of ammonia. I t follows therefore that 4.672 grains of ammonia were con- tained in the original bulk per gallon or 210*24 grs. on the whole volume. The residue after the distillation with barytes was exa- mined for acetic and formic acids but without success. Respecting the volume of carbonic acid eliminated during the process of fermentation I have not yet had the opportu- 24 Mr.J. N. Furze on Fermentation. nity of using an apparatus capable of measuring the amount set free fiorn so large a quantity of wort as 180 barrels. on a small brewing of ale the quantity of gas measured by a very large metre was 7900 cubic feet. The meter having been charged with great care the relative quantities were as fol- lows :-43+ barrels of ale wort attenuated 16.5 lbs. per barrel and gave off 7900 cubic fket of carbonic acid or about 1 1 cubic feet of gas for every pound of attenuation. Again 91 barrels of ale wort attenuated 15 lbs. per barrel and gave off 11,700 cubic feet of carbonic acid or about 11.66 cubic feet of gas for every pound of attenuation. I t being manifestly inconvenient to distil so weak a spirit on a large scale f'rom the necessity of apparatus and arrange- ments totally dicerent from the usual machinery of a brewery the means of preventing the saturation of the gas by the va- pour of alcohol was the next object.This is accomplished in a most simple manner. The tun being air-tight the exit- pipes for the carbonic acid were allowed to dip into a vessel of water to the depth of three feet and by the pressure of the confined gas upon the surface of the fermenting worts the power of holding the vapour of the alcohol in the carbonic acid gas is checked and a very large proportion of spirit thus retained which would otherwise have been .lost. The effect was tested as before by distillation ancl although the retention was not complete a most extraordinary reduction was made amounting in some instances to 80 per cent.of the before- stated produce. The depth of 3 feet is of course an ar- bitrary number but in practice a greater pressure is inconve- nient from the difficulty of keeping large tuns air-tight by common means. The difference of the quantity of vapour dependent upon pressure will be confirmed by the following experiments in addition to the test of distillation. 175 barrels of' porter wort were fermented in a close tun the exit-pipes of which were immersed in water to the depth of3 inches. During the process at three different periods 100 cubic inches of the gas were passed through desiccating tubes 17 inches long ancl half an inch in diameter containing chloride of calcium and on each occasion for every 100 cu- bic inches calculated as dry carbonic acid at a temperature of 5Z0 0.425 grain increase of weight was obtained due to the absorption of watery vapour.181 barrels of porter wort fermented in the same vessel; tlie pipes being immersed 3 feet gave the following result. For every 100 cubic inches calculated as dry carbonic acid at a temperature of 52O only 0.20 grain of vapour was ab- sorbed. I t would appear therefore that the vapour of water 25 @is. Mr. Denham Smith .on Ferric Acid. given OK during the process of' fermentation bears directly on the proportion of alcohol carried away with the carbonic acid If the simplicity of the arrangement is a ground for its recommendation it must be evident that the foregoing appa- ratus would claim the attention of those conversant with the present system as furnishing to the brewer a better control over his fermenting tuns and the production of a stronger beverage from his worts.I have much pleasure in acknowledging the material as- sistance afforded me by my friend Mr. Robert Warington in these investigations. Mr. J. N. Furze on Fermentation. 21 LXXXIX. Observations on Fermentation. By JOHN N. FURZE ESP. 1 N consequence of the practical inconveniences arising to brewers from want of control over the fermenting tuns, and the changes in the worts dependent upon atmospheric temperature I was led to the following experimental obser-va tions. The infusion of malt being made according to the usual practice of brewing the wort or infusion is boiled with the hops and being subsequently cooled yeast to the amount of about one pouiid by weight to the barrel of wort is added and the whole transferred to the fermenting tan The general form of a lwewer’s fermenting tun being that ofa simple open vessel 22 Mr.J. N. Furze 011 Fermentation. the worts lie exposed during their change of state without covering and with free access of air. This as is evident, must expose the fermenting mass to the variations of atmo-spheric temperature which in their turn either check or hasten the operation to such an extent that the ultimate suc-cess of the brewing is endangered and not unfreqnently con-siderable loss is sustained. These disadvantages are occa-sionally avoided in some of the larger breweries by the use of fermenting tuns which are so far inclosed as to leave but sufficient space for the escape of the gaseous matters arising from the surface of the worts when the fermentation is in full vigour.Having tried the above method without finding the desired advantage to resiilt from it new measures of proceeding were taken as follows:-A circular tun was erected whose total content was 350 barrels having a door in the side capable of being made air-tight by lining its edges with coarse serge and applying screw-pressure to the centre of it. To the upper part of this tun which was fitted with windows in the top and sides to afford to the brewer an opportunity of viewing the apparent changes in the worts two India-rubber pipes were attached each of I inch internal diameter to convey away the gas generated during the process; and *in order to pre-vent external interference the ends of the pipes were immersed to the depth of about 3 inches in a vessel of water.These arrangements must not be confounded with the at-tempts of some persons both in this country and in France, to condense vapours which were supposed to rise in great abundance from fermenting liquids and which are well known to have disappointed the expectations of the projectors. On two occasions when the plan of condensation was tried by me there was not any product after passing the gaseous matter through a worm three quarters of an inch diameter and 35 feet in length surrounded with water at a temperature of 54’ for R period of 36 hours on each occasion.Having arranged the improved tun as before described the gas arising from six fermentations was allowed to escape through the water in the external vessel. After the gas had thus been washed it had lost much of the pungency of smell so characteristic of the usual mode of escape and in a few days the water had so far changed that it had a strong fetid odour similar to that of waste starch liquors and certainly not that of the aroma of the hop This from the great dif-ference between the water in question and that of the same bulk which had not been so treated must have resulted from the absorption of a something passing off i n mechanical sus Mr. J. N Furze OTJ Fermentation. 23 pension with the gas. I n order to ascertain the contents of tlie water after being charged with the gas and vapour some of it was distilled immediately after the transmission of the gas, and the result was that from 36 gallons of the water so em-ployed 9 pints of alcohol were obtained of specific gravity 0.850.I t appeared on further prosecuting the matter that more could have been obtained had a larger quantity of water been used and that the action of the water on the gas de-pended for its efficacy in a great degree upon the apparatus itself. In endeavouring to realize more extended results a tub was made which contained an arrangement of three tin plates perforated with holes set one inch apart f'rorn each other through which the gas passed in small bubbles by which means the.washing of the gas was rendered more ef-fectual.In this manner 3 per cent. of rough spirit was fre-quently obtained of specific gravity 0*850 by distillation from the gas produced by one fermentation. All these distilled products were impregnated with ammonia to a considerable amount which would necessarily affect these results as is shown by tlie following. experiments. 45 gallons of water having received a charge of gas from the fernientation of 350 barrels of porter wort had a specific gravity 0*9988 and the attenuation of the worts during the period was about 1-2 Ibs. per barrel as indicated by the sac-charometer of Dring and Fage. Of this quantity 36 gallons were reduced to one-sixth part by distillation of which 16 02. by measure were again carefully rectified and reduced to 4 oz., which had a specific gravity 0965 being equal to 33 per cent.of alcohol at 0+825. I t therefore follows that the 45 gallons would have yielded 15 imperial pints at 0.965 which would equal 5 pints at 0*825 or about 1.4 per cent. of alcohol by volume. ,5 oz. of the original 45 gallons were distilled with bnryta in excess to combine with any acids that might be present, and the product was redistilled with hydrochloric acid ; chlo-ride of platinum and sodium was then added and the whole carefully evaporated to dryness ; the soluble parts having been removed by alcohol left 1.9 gr. of ammonio-chloride of plati-num which indicates by calculation 0- 146 grain of ammonia. I t follows therefore that 4.672 grains of ammonia were con-tained in the original bulk per gallon or 210*24 grs.on the whole volume. The residue after the distillation with barytes was exa-mined for acetic and formic acids but without success. Respecting the volume of carbonic acid eliminated during the process of fermentation I have not yet had the opportu 24 Mr. J. N. Furze on Fermentation. nity of using an apparatus capable of measuring the amount set free fiorn so large a quantity of wort as 180 barrels. on a small brewing of ale the quantity of gas measured by a very large metre was 7900 cubic feet. The meter having been charged with great care the relative quantities were as fol-lows :-43+ barrels of ale wort attenuated 16.5 lbs. per barrel, and gave off 7900 cubic fket of carbonic acid or about 1 1 cubic feet of gas for every pound of attenuation.Again 91 barrels of ale wort attenuated 15 lbs. per barrel and gave off 11,700 cubic feet of carbonic acid or about 11.66 cubic feet of gas for every pound of attenuation. I t being manifestly inconvenient to distil so weak a spirit on a large scale f'rom the necessity of apparatus and arrange-ments totally dicerent from the usual machinery of a brewery, the means of preventing the saturation of the gas by the va-pour of alcohol was the next object. This is accomplished in a most simple manner. The tun being air-tight the exit-pipes for the carbonic acid were allowed to dip into a vessel of water to the depth of three feet and by the pressure of the confined gas upon the surface of the fermenting worts the power of holding the vapour of the alcohol in the carbonic acid gas is checked and a very large proportion of spirit thus retained which would otherwise have been .lost.The effect was tested as before by distillation ancl although the retention was not complete a most extraordinary reduction was made, amounting in some instances to 80 per cent. of the before-stated produce. The depth of 3 feet is of course an ar-bitrary number but in practice a greater pressure is inconve-nient from the difficulty of keeping large tuns air-tight by common means. The difference of the quantity of vapour dependent upon pressure will be confirmed by the following experiments in addition to the test of distillation. 175 barrels of' porter wort were fermented in a close tun, the exit-pipes of which were immersed in water to the depth of3 inches.During the process at three different periods, 100 cubic inches of the gas were passed through desiccating tubes 17 inches long ancl half an inch in diameter containing chloride of calcium and on each occasion for every 100 cu-bic inches calculated as dry carbonic acid at a temperature of 5Z0 0.425 grain increase of weight was obtained due to the absorption of watery vapour. 181 barrels of porter wort fermented in the same vessel; tlie pipes being immersed 3 feet gave the following result. For every 100 cubic inches calculated as dry carbonic acid at a temperature of 52O only 0.20 grain of vapour was ab-sorbed. I t would appear therefore that the vapour of wate Mr. Denham Smith .on Ferric Acid. 25 given OK during the process of' fermentation bears directly on the proportion of alcohol carried away with the carbonic acid @is. If the simplicity of the arrangement is a ground for its recommendation it must be evident that the foregoing appa-ratus would claim the attention of those conversant with the present system as furnishing to the brewer a better control over his fermenting tuns and the production of a stronger beverage from his worts. I have much pleasure in acknowledging the material as-sistance afforded me by my friend Mr. Robert Warington in these investigations