Acetone smell?

[Airborneguy]

I made a DIY lacto starter with some grains, grew a great pelicle, then pitched it into a no-boil Berliner, adding Wyeast Kolsch 72 hours after pitching the lacto.

A monster pellicle formed quickly, covering the entire top of the wort. I'm slightly worried though as it smells like acetone (nail polish), to a T. I actually compared the smell to my wife's nail polish remover and it's dead on.

I hate to utter the dreaded, cliched, total newby words, but:

IS THIS NORMAL?!?!

 

[Glossolalia]

Might be ethyl acetate, the esterification product of ethanol and acetic acid and a common byproduct of Acetobacter and other aerobic bacteria. Sometimes, you get lucky at it reverts to acetic acid. Not sure you can do much. I once made a peach wit that was loaded with it. I let it sit in the cellar for one year. One year later, it was still loaded with it and ended up getting dumped.

Lacto is facultative anaerobic so if you grow it up under anaerobic conditions, theoretically you should minimize growth of aerobic bacteria and thus ethyl acetate formation. That being said, my peach wit WAS fermented in anaerobic conditions...

 

[smokinghole]

I was about to say only time I smelled a hardcore acetone smell is when I made vinegar in my parents basement. I still have to bottle it but it smelled like acetone at the end of summer. Now it smells like vinegar.

 

[Airborneguy]

Thanks. Based on what Glossolalia said, I'm guessing this may have happened because I transported the beer from Manhattan, where I brewed it, to home in my Jeep, which isn't exactly the smoothest ride. It probably oxygenated fairly well on the way home.

I tasted it last night and it actually wasn't bad, but not what I was looking for exactly. I'm going to cold crash it tonight to see if I can stop it before it gets too strong.

 

[smokinghole]

I also had an IPA ferment WAY too hot that gave me a crazy nail polish smell. It was a 90min IPA clone recipe and even that amount of hops couldn't cover it up. So maybe you got too hot?

 

[Airborneguy]

Heat shouldn't have been the problem. I didn't go crazy trying to control the temp like I normally do since the lacto likes heat anyway, but where it fermented it shouldn't have went above 75.

 

[Pogopunx82]

There's hope. My Berliner Weisse smelled intense with acetone and in fear we dumped it. We have a Sour Brown with bugs from the grains and it had the smell a week ago. It was almost 2 months old. Just read this post today and went to see if it still reeked and its entirely gone. I hear brett sometimes produces that smell. Just hold on to it for a couple weeks and it may go away.