Green Acetaldehyde @ Two Weeks - Bottle or Wait ??

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FruityHops

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This is my first brew ever. OG was 1.065, it was a pale ale extract kit and I hit the target 5 gal volume, but gravity was 10 points high for some reason.

It fermented for a week at 64F-65F ambient temp. Then I moved it to 66F-68F ambient temp.

Gravity the day I changed the temp (after 7 days) was 1.017 and color was lite and golden. After three days of warmer temps (10 days total) gravity was 1.013 and color had changed darker amber, almost red.

I was planning on bottling today. Today (13 days total) the gravity is 1.012 and there is a pronounced green apple smell and taste, presumably acetaldehyde.

Should I bottle today and hope the off flavor clears, or let it sit in the fermenter another week in an attempt to clear the off flavor and then bottle?
 
Very good, I'll let it sit a while longer and check on it in a week.

Should I keep it at 68F-70F or move it to where it will be about 66F?
 
Very good, I'll let it sit a while longer and check on it in a week.

Should I keep it at 68F-70F or move it to where it will be about 66F?


It depends on the yeast you're using. Look it up online or double check your notes for the appropriate temperature range for it. Keep it in the correct range for at least another week. Then if you want bring the temp down or cold crash it.

I'm not expert but this is what I would do if I was in your shoes. Good luck and brew on!! [emoji482]
 
Acetaldehyde is a byproduct of yeast fermentation. It's a sign you need to leave the beer on the yeast longer to allow the yeast to finish up the process. It can also be caused by oxidation by allowing to much head space in your fermentor. I'd leave it alone for a while longer and keep your airlock full to prevent air entering the process. There are a few other causes but those are the most common.

Most of the esters created are done so in the beginning stages of fermentation and at this point temp is not a major concern. You may want to warm it up a bit to keep the yeast active but that's more for a D rest. Just don't cold crash.
 
Keep it warm. Acetaldehyde boils at about 70 F. So it would make sense that if you warmed it up you would be smelling it. If you leave it for a couple 2-3 extra days then I bet it will mostly be gone.

Acetaldehyde is caused primarily by stress on the yeast. Use more yeast in the future and/or make a starter. Also make sure it is fresh and healthy and hasn't been sitting around for a year not refrigerated or whatever. Use the freshest yeast for the best fermentations.
 
Very good, I'll let it sit a while longer and check on it in a week.

Should I keep it at 68F-70F or move it to where it will be about 66F?


At this point the temperature isn't going to make much difference. The first 3-5 days is where the temperature is the most critical, after that you can let it rise to let the yeast finish up.
 
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