Question

You are starting to brew beer as a hobby. In the first batch you let the fermentation go for two weeks and produced 4% alcohol. You decided to let the fermentation go longer in the second batch, and left the wort to ferment for three week, resulting in 4% alcohol production.   The third batch was left for four weeks, and still only produced 4% alcohol. You tested, and showed that it was active (that it could ferment). The particular strain of Saccharomyces cerevisiaeyou are using has an alcohol tolerance of 15%. Hypothesize what is causing this low level of alcohol in reference to the brewer's recipe and recommend how a higher alcohol yield could be achieved.

Answer 1

The low level of alcohol in the differently aged beer may be due to the lower level of sugar content in the Brew. To increase the alcohol yield , the amount of malt extract or grain bill may be increased. Alternatively , adding more sugar will also increase the alcohol content.

But , the amount of sugar to be added must be carefully monitored as the excess unfermented sugar will add sweetness to the beer. So periodic addition and monitoring of alcohol content is recommended for an optimim yield of alcohol.