Acetaldehyde

Noticed a strong cider smell when bottling a recent 1 gallon batch. Upon tasting last night, it was still there after a week of bottling. What are the most common reasons and will it go away?

-May have pitched too warm
-Haven’t bottled for 2 weeks

http://www.beerjudgeschool.com/uploads/Beer_Characteristics_Flash_Cards.pdf

This is a great reference for issues pertaining to beer to help you diagnose what may have occurred.

Can this be caused by fruit flies? I thought I read that online.

Acetic acid can be caused by fruit flies.

Acetaldehyde is caused by stressed yeast in my experience. Under pitching and too warm of a ferment. Leaving the beer on the cake can help clean it up.

Could be wrong, but once it is racked off of the cake, it won’t go away.

What style beer was it?

Pale Ale

If it is acetylaldehyde (green apples) it might decrease a little, but not likely. Acetylaldehyde is normally produced by yeast, even more by stressed yeast. But it can also be reabsorbed by yeast after fermentation. Once it’s bottled though, no luck. The yeast in the bottle might absorb a little, but they’ll only help a little.

How long did it ferment?

Before I got good temp control and stir plates I fought with acetaldehyde frequently. Its a precursor to ethanol which the yeast will clean up IF they don’t go dormant first. So, healthy yeast, in proper amounts, with stable temps is the key.

…and don’t try to bottle too soon.

Right!

You should taste your gravity tests. Done equals stable final gravity + no off flavors.

Be aware that there is also a difference between acetaldehyde (green apple) and apple ester (regular non-green apple).  Some yeasts such as WLP400 throw a ton of apple and pear flavors, which has nothing to do with acetaldehyde.  If you severely underpitched or used really old yeast, you could have acetaldehyde.  If you used a Belgian yeast or even American yeast, in some instances you could get the non-green apple ester even with a good pitch.

Dave you are correct. There is the beer myth that Bud has high acetaldehyde levels, but it is due to that yeast producing apple esters.

Reference is Mitch Steele, who worked at AB.
http://hoptripper.com/what-is-quality/

this is true, interesting though that having attended a tasting seminar put on by Siebel, Bud was used as the control beer and was used as the sole descriptor for this off flavor with no spiking of the beer

He does point out that beer educators get this wrong.

true, the microbiologist that led the tasting pointed this out as well at the time, just threw it out there as an interesting tidbit

Just an update…noticed this morning that the suspect bottles had a rim of something at the neck (ala a mini fermentor). Opened them up in the sink and they GUSHED. Guess I bottled too soon? I wonder if the 3 TBS of honey for the gallon batch was too much priming sugar?

You might have bottled before fermentation was 100% complete.  Did you check gravity several times over the course of 3-4 days?  You really need to do that and wait until the gravity stops decreasing before bottling.

3 Tbsp honey seems like the right amount for a gallon.  But if you lost a lot of volume due to yeast sediment and trub, and only had like 3 quarts of beer left to bottle, then 3 Tbsp might be too much.  How many bottles did you get?  And were they regular 12-oz bottles, or 16 or 22-oz?  That will give us a better picture so we can help more.

A ring around the neck of the bottle is often a sign of some form of infection in the bottle.  That along with gushing.  Could be the bottles weren’t as clean as you had thought.

That was my thought.

+1.  Yeah.  What they said is also very possible.