Infection Insight

[italarican]

I brewed a beginner's berliner weisse-type knockoff (recipe below). Everything was going fine until about Day 17. The airlock suddenly had a nail polish aroma coming from it. It was only then I realized the window in my fermenting room (aka guest room) had been shut (presumably by a friend that stayed the night) for about 3-4 days. I believe I most likely got an acetone infection due to warm temps; the fermenter was at about 76 degrees after staying at around 66 the first 2 weeks.

I decided to bottle half immediately and add blueberries to the rest of the batch, let it sit for a week, and hope for the best (expecting the worst). At this point, the bucket smelled strongly of nail polish, but it wasn't noticeable in the flavor.

A week later, the blueberry batch was disgusting: nail polish and almost meaty in quality. I've bottled a bit of it but think this will be a drain pour.

I opened a bottle of the original (no blueberries) batch two weeks after bottling: decent beer with no nail polish in the aroma or flavor (at least not noticeable to me).

I would presume once I smelled nail polish the infection was in the beer, so I guess I'm hoping people could offer insight into why bottling seemed to stunt the infection's progression (or is it probably going to come out eventually)? Is it something about the sugar added during bottling? I'm just pleasantly surprised the first half of this batch isn't a complete waste at the moment.


RECIPE (5 gallons) OG 1.037/ FG 1.009
3.3 lbs Bavarian Wheat LME
1 lb Pilsner DME
1 lb acidulated malt

Boil 15 min 0.75 oz Hellertau

Wyeast Bavarian Wheat

Steep acidulated malt at 155 for 45 minutes
Add malt extract
Boil for 15 minutes w/ Hellertau
Pitch yeast at 68 degrees

Added 1 tbsp lactic acid/gallon at bottling

BLUEBERRIES (to remaining 2.5 gallons)
3.0 lbs frozen blueberries
On stove w/ bit of water (forget how much), heat to 150 for 5 minutes
Mash with sanitized potato masher

 

[JoeBronco]

Chances are its just normal fermentation smells. Wheat beers, depending on the yeast strain give off some weird smells, esters and fossles. If you bottled the beer to soon the yeast did not have enough time to clean it self up and get rid of the waste product.

Its unlikely that its really Ethyl acetate. Common levels in beer: 8-70ppm. Its formed by the condensation of acetyl CoA and ethanol. Smells of nail polish and solvent at high concentrations, but can have a slightly fruity aroma at low levels. But again, this normally goes away when you let the beer ferment out.

 

[veritas524]

Nothing about that makes me think infection... fusels can develop at higher temps which can have a hot alcohol smell and taste. Bottling sooner rather than later will hurt you more than help you. Always let fermentation run its course and don't freak out about anything until the beer is properly conditioned.

 

[italarican]

Now I'm even more curious.

I hit the OG by day 14 (same on Day 17). When the bucket reeked of nail polish on day 17 and I bottled, the beer itself didn't seem to have the nail polish taste (or even aroma once in the bottle). 2 weeks later, that beer tastes fine (bavarian wheat qualities). The beer the remained in the bucket, however, smells/tastes of nail polish and funky meat.

The blueberries I added certainly could have contributed, but the nail polish smell started before that.

 

[passedpawn]

I ferment BW warm. No problem. I don't think temps were the problem.

 

[bluenadas]

Acetyl CoA is not produced during fermentation. Acetylaldehyde is as the yeast convert the pyruvate to CO2 and ethanol.

Acetyl CoA is produced in mitochondria after the oxidation of pyruvate, and then enters the citric acid cycle for production of NADH, FADH, and ATP during aerobic respiration.