I’ve heard mix opinions about green beer. I know it’s acetaldehyde that gives it’s green apple / tart flavor. But where I have a misunderstanding is when yeast starts transforming acetaldehyde back to ethanol.
I’ve heard you should keep the beer in the primary for a week (or more) longer than usual to give the yeast some time to metabolize the acetaldehyde because once you take it off the trub there is nothing you can do about it. But also, I’ve heard that you can just condition it in the bottle for a few weeks and the same thing will occur.
So, what is the best way to go about the acetaldehyde? I brewed some extract batches that had that green apple taste but because I was young and inexperienced, I’d drink it thinking it was just how extract homebrew tastes. But, now I’m not convinced.
That’s part of the “clean up” post attenuative phase. It can last longer depending on yeast health, beer strength and how cool the overall fermentation temp was. One way to combat this is to raise the temp of the beer several degrees towards the end of this stage. Another is to wait more days if you have less control over ferm temps.
To me it really doesn’t taste like apple but like raw pumpkin- which I think is absolutely disgusting in beer.
I’ve never had a problem with it in bottles, but those have been primed with sugar so I think the yeast actively do a good job of cleaning up any acetaldehyde.
I put some bottles of my two green beers in the fridge for about 24 hrs or so… and they are definitely getting better. They are much more drinkable now! I was getting scared there for a second.
Live yeast cleans up the beer. So whether it’s secondary, primary, or in the bottles, as long as live yeast is still working it will clean up the off-tasting by-products. Time may be an issue depending on the exact procedure you used, but live yeast will still do their work.
There are situations where one can rush their beer but one has to stick with certain criteria in order to accomplish it successfully. We can help you with that.
Otherwise, homebrewing to a certain degree is an exercise in patience. Give yourself a couple weeks in primary and use healthy yeast. Next year you’ll be procrastinating, which can present other problems…