Nail polish flavor

Hi all.

My first batch in years has come out with a decent scent ond taste of nail polish. It also has no head at all, despite being carbonated. Pretty standard grain bill that has produced normal head before.  As I did a few things differently to the past I wanted to check a couple of items.

Infection.  I think this is the most likely cause, so if that is the case I have missed something from a housekeeping perspective.  Easy fix

Yeast stressed during fermentation has been highlighted as a possible cause.  I did a stir plate for the first time.  The beer fermented out fine in a timely fashion, so no issue with pitch rate I don't think.  Temperature was governed well inside the yeast parameters.  With the stir plate though should I be aerating the wort?  The stir plate keeps in suspension, but I'm not sure it is introducing oxygen.  I had no air lock, but just loose foil over the yeast flask.

Inline oxygenation.  Could an over supply of oxygen cause this?  I read on wyeast website that excess O2 will come out of solution so no real issue, but other searches suggest otherwise.

That's about it...As mentioned I blame an infection, but can't hurt to put it out there before I go again.

Thanks in advance.

Hi Derek,

Nail polish aroma/taste is caused by ethyl acetate.
This is usually a sign of an issue during fermentation such as yeast stress or high fermentation temperatures.

Using foil to cover the top of your flask tightly when making a starter is fine, as long as your sanitary, the starter needs some oxygen exchange.

Cheers, Kev.

Thanks Kev.  Had a beer on the weekend...been 2 months in the bottle and the nail polish has diminished greatly.  Near gone in fact but is a bit yeasty.  (1007 German Ale typical)

Still think my process can improve still.

kevino said:

...or high fermentation temperatures.

Click to expand...

Agreed - watching your fermentation temperatures, especially during the first couple of days, is crucial to avoiding such issues. When the yeast takes off, it can produce surprisingly high temperatures for the first several hours, and it is during this time that such undesirable byproducts can be made. I actually like the smell of nail polish, just not in my beers. ;D