Acetaldehyde in wine?

[casebrew]

Health issues lately. I left 11 gallons of LoQuat wine on the must for 4 months. In a keggle with a Farberware lid. It occurred to me the other day that it probably settled well enough that I could syphon off a gallon. I took a bottle to a housewarming.

Flavor is not right, a harshness masks the fruityness I usually get. Seems to be a headache in every glass. Acetaldehyde perhaps?

Today I pressed it, into a couple open-topped containers. Fluid temp is 72. Will any acet- evaporate? I know they do it for Lagers.

 

[RPh_Guy]

I'm not a wine expert but I'll reply since you haven't got a bite yet.

Acetaldehyde tastes like green apples, and has a bit of harsh tartness. It certainly won't cause a headache.

There are lots of potential other off-flavors or other things that may be out of balance, so unless you can better describe the flavor and/or your process, I'd be shooting in the dark trying to guess what might be wrong.

Headache is generally associated with higher alcohols (fusel), typically from fermenting too hot.

Will any acet- evaporate? I know they do it for Lagers.

No, it doesn't "evaporate". I think you're thinking of diacetyl, which also doesn't "evaporate". Contact with yeast generally removes both of these fermentation byproducts.
It sounds like you left it in primary for 4 months, yes? You shouldn't have either of those flavors in the wine, unless maybe if you had a very unhealthy generation and something went horribly wrong during conditioning, or maybe a contamination.

Hope this helps.

 

[casebrew]

Yes to the green apple/harshness. But LoQuats are members of the apple/pear family, so I didn't recognize it as a problem.

So far as the rest, then what is it that traditional Lager brewers do when they raise the temp to 'cook off' something.

Meantime, I'll Wiki Fusel...

 

[RPh_Guy]

what is it that traditional Lager brewers do when they raise the temp to 'cook off' something.

Raising the temp into the upper 60s increases the rate at which yeast reabsorb and degrade the diacetyl.
It is not being "cooked off" or evaporated.

Again, my educated guess is that it's not acetaldehyde, likely something else. So many things can cause harshness.
Sorry your wine didn't turn out great.

 

[casebrew]

28 hours in the open did do something. Last evening just walking into the kitchen gave me a headache. I even sealed the bottom of the door between kitchen and bedroom, I didn't need the overnight headache.

So this afternoon the kitchen smelled better. Even with my face right in the 'vat' it smelled better. A taste test showed the usual harshness if un-aged brew, much better. All as compared to a sample of the not-yet-open-aired stuff.

I'll sample again tomorrow morning, I expect to put the lids on then. Darnit, I'll have to let it settle again- I could have syphoned off some clear stuff into a bucket, but I mixed it all up when I pressed it.

 

[casebrew]

So I think I'm sticking with the acetaldehyde hypothesis. It boils at only 68f, ought to air right out of there. Diacetyl is similar, 72f?

My reading on the net said for sure it causes headaches. Frinstance, with hangovers, caused by the body making acetaldehyde as part of the break down process of alcohol.

Fusel alcohols boil in the 350f range, less likely to air off.