Given a recent experience with kegging an ale too soon and learning what that green apple rubber glove came from, how do you know when Acetaldehyde is gone?
My current brews are lagers OG 1.050, that hit 1.020 in a week. I raised the temp from 50 to 60. After a week at 60 they are at 1.010. I want to start my drop to 35 but I’m leery of Acetaldehyde.
Any knowledge on this would be awesome.
“Freedom is temporary unless you are also Brave!” - Patriot
I usually taste my hydrometer samples.
I’ll try that.
“Freedom is temporary unless you are also Brave!” - Patriot
You get used to how yeast strains work. But until that happens, you have to rely on taste/smell like amanda sugested.
This. Acetylaldehyde is something yeast clean up after fermentation. If fermentation is done and you don’t taste it, you’re good to go.
How fast are you raising the temp for your diacetyl rest? You may actually create acetaldehyde if you stress the yeast by raising/lowering the temp to quickly.
About 1-2 deg F per day is a safe bet.
Any yeast stress can yield acetalaldehyde - underpitching, under-aerating, temp. fluctuations, etc. Check all that out as well.
I’ve had this issue with my kolsch and found that I need about 1.5x the amount of yeast recommended by Mr. Malty. O2 and temp. control really helped, too.
If you find some acetaldehyde you can sometimes mitigate it with an even warmer rest than your diacetyl rest. Acetaldehyde has a boiling temp of around 72f IIRC. so it will gas out if you keep the finished beer there for a couple days.
^^^ This ^^^
My d rest temp increase was done in one chunk. I didn’t know about stepping up to that. Will next time.
I’m going to go take another reading and taste. Maybe I’m there and can start my stepped drop to 35.
Thanks for all the great info.
“Freedom is temporary unless you are also Brave!” - Patriot
The bohemian is 1.008nd tastes clean. The American is 1.010-09 and tastes clean. I’ve started my crash drop. Will keg them in a week.
“Freedom is temporary unless you are also Brave!” - Patriot
For reals? I think this just blew my mind.
Or maybe it’s the wine I’m drinking. ;D
I’d agree with this. It seems like most of the time I’ve experienced acetalaldehyde it has been from extreme underpitching
I’ve never gotten it from crash cooling though. For what it’s worth.
I guess I always associated “crash cooling” with post-fermentation and “diacetyl rest” with active fermentation.
Temp swings AFTER fermentation = ok.
Temp swings DURING fermentation not ok.
Oh, i see what you’re saying. Yeah, I’ll agree with that.
I agree with of much of what was said. In addition, having a healthy/viable pitch into a properly aerated wort is helpful toward minimizing this off-flavor. Allowing the yeast ample time to clean-up after fermentation is the key to mitigating acetaldehyde. This then must be checked by tasting before racking/lagering into the keg or bottling. Time is on your side.