Kolsch Gone Cider or Fruity

[blackstrat5]

I produced a Kolsch back in the end of May. Pilsner and Wheat Malt.

It lagered at 40 degrees for 5 weeks. I racked it to a keg, where it sat at room temp until there was room in the kegerator for it about two weeks later.

When I racked it, the beer was spot on for a Kolsch. It was great. Now that it's carbed I gave it a try and somethings amiss. The nose is straight up peaches or cider. The kolsch smells like im sticking my nose into a glass of woodchuck pear cider. It's in the taste at the beginning, and does resemble a fruity flavor I can't put my finger on.

It wasn't like this when I racked it. What happened?

 

[Reno_eNVy]

That sounds like acetaldehyde. It's a precursor for ethanol in the metabolic-pathway of yeast fermentation. Did you ferment at 40*F? If you did this may be the case since Kolsch yeast is an ale yeast and, while it works at cooler temps, it will have a hard time "cleaning up" the rest of the acetaldehyde if it's cold.

EDIT: And what yeast did you use?

 

[blackstrat5]

I did the primary fermentation around 62 degrees for two weeks with the Wyeast Kolsch yeast 2565.

Like I said it really tasted awesome when I racked it to a keg. After it sat in the keg warm (68-74 Room Temp) and was put back in the kegerator for carbonating and serving it got that weird fruit taste.

I thought acetyldehyde would be a product of the primary fermentation which I didn't taste it then. Also, long lagering/conditioning times would help reduce it. It smells like peaches or apples...

 

[14thstreet]

Looks as if you got some yeast-derived esters there, even if a good dose of it. Probably typical, especially now that it is carbonated. That will help release some aromatics. What's funny is that my kolsch started out like that when it was young but now with some age in the keg it has mellowed. I fermented a bit warmer than you but all the rest is the same.

 

[blackstrat5]

So you think that this is a primary derived flavor that wasn't detectable at racking. But with carbonation it's perceivable?

 

[14thstreet]

It's possible, though I can't say for sure...every fermentation is different, you just try to control the variables that you can. I do remember being somewhat underwhelmed with my kolsch upon racking. Rather nondescript as far as what I expected from the yeast (some fruitiness, not a fruit bomb). I only detected such slight character when the beer was carbonated. Did you use a starter or just pitch from a vial/smack pack?

 

[tagz]

I have had several beers where flaws show up after carbonation.

 

[blackstrat5]

I used a starter calculated from Mr Maltys site. I was expecting fruitiness, but not in your face peaches. I guess the only solution is brew this again