'Green Beer' (Acetaldehyde)

So I went to my first local home brewer meeting last night and got notes on my first all grain IPA. Most members mentioned it had the green apple flavor and immediately I recognized it too. So here's the question: Since I have it kegged and in a the keezer, will that mellow over time? Should I detach it from the lines, degass it and let it sit for a few weeks to clear the flavor up? Otherwise I will just have to suffer through the taste and see if my friends will drink it.

 

The flavor should fade with time, hence the association with green or young beer. The chemical is eventually converted to ethanol. You could pull the beer out of the keezer and let it warm up a bit to speed up this process, but you can keep it carbed.

Particular yeasts produce more than others. This can impact the rate that the flavor fades. What yeast did you use?

 

Just used a packet of 05.

 

I've had a lot of strange flavor in my young beers like what's described here. Sometimes it takes 5 or so weeks to go away in the bottle.

 

Bear in mind acetaldehyde production increases dramatically with warmer fermentation temps. Chris White (White Labs) did a test with two identical ale worts for his Yeast book, one at 66F and one at 75F.

With a flavor threshold of about 10ppm, the beer fermented at 66F only contained 7.98ppm of acetaldehyde, the batch at 75F had 152.19ppm.

Best way to eliminate it is not to produce it! Get those temps down!

 

The flavor should fade over time... But from what I understand, it's the yeast cleaning up after itself which converts it back to ethanol, so longer in the primary is probably the fastest way. Obviously your past that now though, but maybe warming the keg back up could speed up the process?


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So does that mean that we shouldn't bottle age at 75?

 

shouldn't you bottle age beers at cellar temps.....

 

I thought I've read on here many times to age at 75 in the bottle.

 

I have always subscribed to carbonate at 70-75F, age at 50-60F.

 

Once the beer is fermented, you can bottle condition or cellar at whatever temp makes you comfortable. The process of bottle conditioning/carbonating won't significantly impact the acetaldehyde level. It's de minimus at that point.

 

The temperature you use has nothing to do with how you feel about your beer. Temperature matters, and selecting the proper range influences your beer pretty dramatically.

Fortunately for OP, his beer is in a keg, so bottle conditioning is de minimus.

 

My post wasn't a model of clarity. Temp control during fermentation is absolutely critical. Once the beer is done and you're conditioning, temp still has a direct impact on the quality of your beer, but it's less critical to maintain the +/- 0.5C consistency.

I recently signed up for a company out of Vancouver that offers craft beer from all over the world on a beer-of-the-day basis. Each day is a different brew from a different brewery. You can choose to order or not each day, and your card is charged at the end of the month when everything ships. I ordered 7-8 beers, and will not be ordering again because they don't keep the beers chilled. I assume they sit in a warehouse for a month, un-temp controlled, before shipping. None of the IPAs I ordered had any nose/flavor whatsoever, and I *know* its a quality control issue. It's a fascinating business model, but they need to change their shipping/handling policies.

 

Bottle condition (carbonate) that temp is fine but to age its preferred to do it at cellar temps.