Author Topic: Acetaldehyde flavoring  (Read 2213 times)

Offline bullybullybrew

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Acetaldehyde flavoring
« on: September 19, 2016, 02:25:52 PM »
Hey Guys,

I'm fairly new to all grain brewing and my first two batches have had a bit of a green apple acetaldehyde taste to them which I discovered after kegging them. Is this something that will mellow with time in my keggerator? According to the attenuation, it was a good fermentation so I'm not sure whats going on. Is there anything I can do to remedy?


Offline brewfun

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Re: Acetaldehyde flavoring
« Reply #1 on: September 20, 2016, 11:56:41 AM »
Acetaldehyde can come from incomplete fermentation. Just because the yeast has finished consuming sugar doesn't mean it's finished working. Acetaldehyde is an intermediate step and the last one before ethanol is created. You can see terminal gravity and still have acetaldehyde show up in the beer.

If you primed the keg with sugar, this could just be temporary and will disappear in a short while.

On the other side of fermentation, acetobacter break down ethanol into acetic acid (vinegar). The first step here, is acetaldehyde. Acetobacter is aerobic, so any air mixed in while racking could let it flourish. However, if good sanitation was followed, acetobacter isn't usually a problem. It's usually very slow growing or can't thrive at all, with good techniques and refrigeration.

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