Extract from the Naval Chronicle for Thursday, Feb. 18, 2010

And again, on the same page, another entry from 1803, on a topic of much interest to sailors of the day.

ARTIFICIAL YEAST.
THE following is a method adopted in Germany and Sweden, for making artificial yeast : To 100 pounds of the best malt, consisting of one part of malted wheat, and two parts of malted barley, dried in the open air, and well ground or bruised, add 10 pounds of good hops, and brew the mixture with 350 pounds of water to form wort. After a short boiling, separate the grains and hops from the wort; which last, by continued boiling, may be reduced to 175 pounds. Cool it down, as soon as possible, to seventy degrees Fahrenheit, and then mix it with thirty-two pounds of yeast, which, the first time, may he of common brewer's yeast, but in every subsequent operation, or the artificial. The wort will soon ferment, and in a few hours it will be covered with a thick yeasty froth; the whole mass must then be strongly agitated, and, at the same time, well mixed with from fifty to seventy-five pounds of fine ground meal of wheat or barley, either malted or unmalted. In a cool place this yeast will keep ten or fifteen days in summer, and four or five weeks in winter.

X, 193