extremes, we are still disposed to think that medium temperatures during fermentation, will be found to produce the best beer in every respect. Let us therefore take a range of from 52° to 78° F., thus allowing 26° to be gained during the fermentation, which is enough for the attenuation of any sort of beer when brewed in proper season. We must now keep in mind, that if the proper quantities of good yeast have been employed, (see Yeast,[deeplink needed]) for every rise of one degree in temperature, there should be a corresponding loss of gravity in the worts of 1 lb. per Long, or 2.78 by Allan’s or Bates’ instrument. For example,—if worts of 42 lbs. gravity per Long be got together in the gyle-tun at 52°, when the temperature rises to 78° they should have lost 26 lbs. of gravity, and thus be attenuated to 14 lbs., when tried by the instrument. We now proceed to describe the appearances exhibited during fermentations of different kinds, and first—
The Regular Fermentation.
We shall now proceed to describe what we consider a sound and regularly good fermentation. In such fermentation, five distinct changes occur, followed, after a certain stage, by a highly pungent aroma, which rises with the carbonic acid gas. If this aroma throughout the process be sound and vinous to the smell, we may feel assured that the
