When I read about tartaric crystals forming in wine bottles that haven't been cold stabilized it's usually about the visual impact and not about lowering the acid level. Yet discussions about chilling wine for an extended period for the purpose of precipitating tartaric clearly indicate that acids can drop a meaningful level.
Why is there no discussion of changes in a wine's acidity post bottling or is the typical post bottling chilling too minor to cause a meaningful impact to acid levels?
I'm hoping that I get a substantial drop in acidity with cold stabilization of a zin. My pH is around 3.06, due to unripe grapes, and a MLF is difficult to start. Hopefully, if I can get the pH up to about 3.2 by chilling it down, then the MLF might proceed. Is this too much to expect?
Lee
I seem to remember unripe fruit has a high level of Malic Acid. Cold stablization will only percipitate Tartaric Acid.
Fred
stabilization of
You're right, but if I can precipitate enough tartaric, then the pH might (??) rise enough to be more conducin=ve to an MLF. I'm just not sure how much change in pH one can expect with cold precip.
Lee
Unfortunately not. If your pH is below pH 3.6 when you cold stabilize, your pH will DROP rather than rise with cold stabilizaiton.
How does the wine taste? Is it acidic enough that you could remove some acid chemically?
Dave
**************************************************************************** Dave Breeden snipped-for-privacy@lightlink.com
Lee,
I agree with Dave - it is among the first things taught in wine chemistry at university, and is related to the different dissocation curves of H2T, KHT, and T=. Below 3.56 for wines, removing KHT actually encourages more dissociation of H+ from the H2T, resulting in a lower pH. So cold stabilisation will make things worse.
3.06 is not great, but you could try acclimatising your bacteria by starting them at 3.3 or so, and gradually drop the pH before pitching. It works when preparing yeast for sparkling tirage!Cheers,
Andrew
Andrew/David,
Is the decrease in PH temporary? With the lower TA and aging you would think the acids will reach some equilibrium over time?
Thanks
Joe
Hi Joe,
No, it's permanent.
The acids will indeed reach some equilibrium, but it may not be the equilibrium that you want!
:-)
How does the wine taste? TA has a much greater influence on flavor than pH.
Dave
**************************************************************************** Dave Breeden snipped-for-privacy@lightlink.comLee:
The Wyeast liquid ML culture works from pH 2.9, it's based on some Oregon strains. I've used it with good results on wines just under
3.0. The only problem is that the ML will take a long time at this pH.Pp
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