BEER 



317 



strong worts are prepared, and the malt is exhausted either for table beer, or for 

 a return, as pointed out above. The last sparges are made 5 or 6 cooler than tho 

 first. 



Tho quantity of hops seldom exceeds four pounds to the quarter of malt. The 

 manner of boiling the worts is the same as that above described ; but the conduct of 

 the fermentation is peculiar. The heat is pitched at 50, and the fermentation con- 

 tinues from a fortnight to three weeks. Were three brewings made in the week, 

 seven or eight working tuns would thus be in constant action ; and, as they are usually 

 in one room, and some of them at an elevation of temperature of 15, the apartment 

 must be propitious to fermentation, however low its heat may be at the commence- 

 ment. No more yeast is used than is indispensable : if a little more be needed, it is 

 made effective by rousing up the tuns twice a day from tho bottom. 



When the progress of the attenuation becomes so slack as not to exceed half a 

 pound in the day, it is prudent to cleanse, otherwise the top barm might re-enter the 

 body of the beer, and it would become yeast-bitten. When tho ale is cleansed, tho 

 head, which has not been disturbed for some days, is allowed to float on the surface 

 till the whole of the then pure ale is drawn off into the casks. This top is regarded 

 as a sufficient preservative against the contact of the atmosphere. Tho Scotch do not 

 skim their tuns, as the London ale brewers commonly do. The Scotch ale, when so 

 cleansed, does not require to be set upon close stillions. It throws off little or no 

 yeast, because the fermentation was nearly finished in the tun. The strength of tho 

 best Scotch ale ranges between 32 and 44 pounds to the barrel ; or it has a specific 

 gravity of from 1/088 to 1'122, according to the price at which it is sold. In a good 

 fermentation, seldom more than a fourth of the original gravity of tho wort remains 

 at the period of the cleansing. Between one-third and one-fourth is the usual degree 

 of attenuation. Scotch ale soon becomes fine, and is seldom racked for the home 

 market. The following Table will show the progress of fermentation in a brewing 

 of good Scotch ale : 



20 barrels of mash-worts of 42 pounds gravity 



20 



returns 



860-6 

 122 



12)982-6 



pounds weight of extract per quarter of malt = 81 



Fermentation : 



March 24, pitched the tun at 51 : yeast 4 gallons. 



April 



25. 

 28. 

 30. 



1. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 



Temp. 

 52 degrees. 

 56 

 60 

 62 

 65 

 66 

 67 

 67 

 66 

 66 

 64 



Gravity. 

 41 pounds 

 39 

 34 

 32 



29 added 1 Ib. of yeast. 

 25 pounds. 

 23 

 20 

 18 

 15 

 14*5 cleansed. 1 



Dr. Uro was employed to make experiments on the density of worts, and tho 

 fermentative changes which they undergo, for the information of a Committee of the 

 House of Commons, which sat in July and August, 1830 : the following is a short 

 abstract of that part of his evidence which bears upon the present subject : 



' My first object was to clear up the difficulties which, to common apprehension, hung 

 over the matter, from the difference in the scales of the saccharometers in use among 

 tho brewers and distillers of England and Scotland. I found that one quarter of good 

 malt would yield to the porter brewer a barrel imperial measure of wort, at tho 

 concentrated specific gravity of T234. Now, if tho decimal part of this number be 

 multiplied by 360, being the number of pounds weight of water in the barrel, the 

 product will denote the excess, in pounds, of the weight of a barrel of such concentrated 

 wort over that of a barrel of water, and that product is, in the present case, 84'24 

 pounds. 



'Mr. Martineau, jun., of the house of Messrs. Whitbread and Company, and a 



1 Brewing,' Society for Diffusing Useful Knowledge, p. 166. 



