Hello from Spain:

I've just finished malolactic fermentation and the wine is too acid.
However it only contains 0.5g acetic acid/L. The TA is correct (6.0). I've
made CaCO3 proofs and I can get through TA=5 with out pH problem, but it
still tastes too hard. I'm thinking that it could be a problem of
acetaldehyde or ethyl acetate, but I'm not sure. What can I do? Any
suggestion?


Thank you for your help

David

David,
Is this a red and are you expressing the acid as tartaric? Were the
grapes very moldy? (I'm wondering if the source of the acetic is moldy
grapes or a film yeast and oxygen exposure.) That does not sound like
an exceptionally high acid level.

You are doing a double salt with that chalk, right? It acts
preferentially with tartaric, so most people pull off 25 to 35% of the
wine to be treated and add all of the chalk to tha. Once it eats all
the tartaric, it goes after the malic. Then just blend it back in
with the whole batch.

If you are sure you have 0.5 g/l acetic you are getting pretty close
to the detectable range and that could be why it tastes sharp to you.
Have you considered blending to reduce that? I would be very careful
if I did not know the source of the acetic acid; (this is not an area
I have a lot of experience in). Pastuerization is one way to stop
acetic acid formation, but that is pretty drastic. Hopefully some
others will have better ideas for you.

Regards,
Joe



wrote in message ...
Hello from Spain:

I've just finished malolactic fermentation and the wine is too acid.
However it only contains 0.5g acetic acid/L. The TA is correct (6.0). I've
made CaCO3 proofs and I can get through TA=5 with out pH problem, but it
still tastes too hard. I'm thinking that it could be a problem of
acetaldehyde or ethyl acetate, but I'm not sure. What can I do? Any
suggestion?


Thank you for your help

David