Kolsch WLP029/White Wine

[yard_bird]

Greetings all,
Does anyone know or hypothesize what compound is responsible for the white wine flavor described by these BJCP guidelines for Kolsch? The last Kolsch I packaged (WLP029 fermented at 61-63 for a week, then 66 until finished) had a surprising amount of apple/pear, but of course my nose is telling me this is acetaldehyde. I don't remember having this style with the "pleasant, subtle white wine character" described by BJCP. To me a lot of white wine has an apple/pear/apricot flavor.

I guess I'm curious as to what makes the white wine flavor distinct from what I think tastes like acetaldehyde. Is this an ester? Would something like this age out with cold conditioning? For what it's worth, none of the past five or so beers before this have had acetaldehyde, and same goes for the last two or three so I think I can rule out an infection that could cause acetaldehyde. White Labs says this yeast doesn't do well below 62, so my guess is I stressed this yeast.

My latest Kolsch has this flavor but far more subtle. Same yeast, but fermented a little warmer. Still a few days before it gets packaged.

 

[BrewSomeMore]

There may be some ester that gives a subtle white wine flavor but I think it has more to do with the malt you use and interaction between the two. A good German pilsner malt usually gives me a hay/grapey kind of flavor.

 

[yard_bird]

Good to know. I remember using German pils for my base, I'll see if I can taste it in my cream ale that was 50/50 pils/2-row.

 

[yard_bird]

Record keeping: after 2-3 weeks at fridge temp the white wine character dies down substantially. This is also about 2 months after brew day. Still present, but pleasant.

For what it’s worth, new Kolsch with same yeast and the same pilz has way less of this flavor/aroma. That being said it’s domestic pilz so that may be the difference.