Hot answers tagged

6

Given that it happens a long time after your beer has reached FG, I doubt it's due to insufficient oxygen in the wort at pitching time. If it were insufficient oxygen, that would lead to a poor ferment, with the CH3CHO being created as the penultimate step in fermentation (conversion of pyruvate into acetaldehyde and carbon dioxide) but the poor fermentation ...


6

Upvote on the question, and someone will undoubtedly come by with a better answer, but here goes off the top of my head: Acetaldehyde (a-cee-tal-de-hide....nobody says it right!) is a precursor to alcohol. It is an intermediate compound that is formed prior to the formation of EtOH/ethanol during fermentation. So the weird thing is that acetaldehyde is ...


2

I've never tried heating beer, although given that commercial beer is pasteurized at around 165F/74C - far above your 20.2C/68F it may work. I'm not a chemist, but my understanding is that the 68F boiling point is for the pure substance - once dissolved in water the boiling point will change, the same as when salt is added to water changes the freezing and ...


2

The smell of apples is totally normal in beer fermentation. The chemical compound acetaldehyde gives the characteristic green-apple flavor and aroma. It's an intermediate in the synthesis of ethanol from glucose by yeast. Usually warm conditioning is enough to reduce levels to below flavor threshold. Factors like not pitching enough yeast or not ...


1

Several causes and solutions, in this case I would say a combination of premature flocculation, lack of oxygen pre pitch, under pitched and possibly post fermintation o2 exposure. Solution so you don't get a 4th batch like this. 1)Areate wort before pitching yeast, consider direct o2 gas. 2) Use a yeast starter to solve the underpitch and premature ...


1

Acetaldehyde after bottling is a classic sign of oxygen exposure, and is the main reason we wait a week or more before drinking bottled homebrew. Noticeable CO2 shows up in just a few days, but the acetaldehyde (normal byproduct of glycolysis) only gets converted to alcohol later, when there is no more oxygen around. From your procedure, I think you are ...



Only top voted, non community-wiki answers of a minimum length are eligible