Benefits of Red Wine Cold Stabilization

As far as I've ever heard, the point is mostly to avoid having tartaric acid precipitate out after the wine has been bottled. This is generally considered more of a cosmetic issue, as the tartaric acid crystals are really not harmful, and don't have any bad effects on the wine. Less often, it can be used to reduce the amount of acidity, although I believe this only works with grape wines, since their acids are predominantly tartaric. Fruit wines tend to have mostly malic and citric acids, and those are more soluble (as I recall).

If you have low acidity, cold stabilizing may not precipitate any tartaric. If you feel pretty sure you are going to add some afterwards, I can't think of any reason to bother with cold stabilization.

Doug

That's exactly what I was thinking Doug. Thanks so much for your comments...

It should help with clearing the wine. I typically add a fining agent before cold stabilization. The cold temperatures supposedly help precipitate fine sediment along with acid crystals. The fining agent just helps things along.

Bryan

You might have that slightly backwards. The cold can presumably help the fining agent precipitate. Not the other way around. The fining agent is a positive or negatively charged particle, attracting an opposite charged particle (such as a protein causing haziness, or suspended solids). The cold stabilization is a tactic for precipitating tartrates.

If the OP writer has a cloudy red wine, he might want to consider egg white fining. If he added tartaric, then cold stabilization might be appropriate. IMHO, time is the best agent for clarifying red wines. Aging in bulk. If you have added tartaric acid back at the beginning of fermentation, there is a greater likelihood of tartrate crystals - and cold stabilizing will help get those out before bottling. otherwise, seems pointless to me. I almost always use bentonite and cold stabilization with white wines. Never used anyhting other than time for reds - except once when I used egg whites just cause I wanted to try it!

Good info Bryan. I'm more worried about precipitating out much needed acid than aesthetic issues associated with tartrate crystals. I'm dealing with low acid wines that were acid-adjusted prior to fermentation. If I cold stabilize and then end up having to add more tartaric afterwards to get the acid back up, I suppose I've defeated the purpose of cold stabilization.

I'm I right??

. I'm more worried about precipitating out much needed

Not exactly; those tartrate crystals will still form over time at cellar temperatures in my experience so you are going to lose the acidity no matter what. If you have low acid and low pH it sound like you have more tartaric than malic so it certainly won't hurt to cold stabilize from the pH perspective (depending on what you mean by low acid). If the TA were 5.0 on a red, I would do nothing but let it sit if it tasted balanced. If it were less than that and my pH was not above 3.6 I might use citric acid over tartaric. That might be another option open to you. Use a different acid.

Joe

I think citric acid might cause problems in wines that went through ML

- or is it only when they are going through ML? In any case, if the pH is low, there is not much potassium in the wine, so there might not be any tartrate precipitation to speak of. It's really not a big deal on reds anyway, I wouldn't do the second cold stabilization if the acid needed correction after the first one.

The one good reason for cold stabilization on reds I can think of is when the acid was adjusted to high levels to lower down the pH. In that case the acid reduction is usually quite significant, so cold stabilization is often needed to make the wine balanced. Again, that's not the case here, just answering the more general question on potential benefits of CS.

Pp

My understanding is that cold stabilization precipitates out excess acid. It's that same excess acid that results in crystals. If your wine is low in acid I don't expect anything will precipitate.

My cold stabilization experience comes from making white wines from Finger Lakes, NY grapes, which are typically high in acid. Cold stabilization reduced acid to acceptable levels. In no case did it reduce the levels below anything desired.

Please note that this is anecdotal evidence; it's hardly scientific. Hopefully someone who's done (or read) the reseach can chime in.

Bryan

How do you know if a low pH and/or low acid wine is low in malic instead of tartaric without conducting a paper chromatography test?

My pre-fermentation, post-adjusted pH was nearly ideal at .65 with a pH of about 3.3. It was .50 with pH of 3.7 before adjustment with tartaric acid. I expect acid to be between .55-.60 after ML which is right where I want it. I fear cold stabilization could take me out of the desired range.

Charles E "How do you know if a low pH and/or low acid wine is low in malic

Paper chromatography won't tell you how much malic or tartaric is in your wine...it will just tell you if either acid is in the wine. I guess you could make a guess by the size of the spots compared to each other but it's really a yes or no type test.

" My pre-fermentation, post-adjusted pH was nearly ideal at .65 with a

That 0.55 to 0.60%TA is a nice target for a red wine. Why don't you wait until ML is finished, test (be sure to get the CO2 out of your sample) and then decide. There's no hurry. If you're still concerned put a bottle of the wine in the frig (I like to cold condition at 32F) for a week and test. Then you will know what to expect with the bulk wine. I've done reds with and without cold conditioning...at worst you will get some tartrate crystals in your bottles but they don't affect taste.

Bill Frzaier Olathe, Kansas USA

It's a rule of thumb - as grapes ripen, the TA goes down and pH goes up. The change in TA is due to a loss of malic acid while the tartaric acid stays stable. So riper grapes will have a lower ratio of malic:tartaric acid. In your case of starting values of 5g/L TA (low acid) and 3.7pH (relatively high pH), my guess is there should not be much malic acid - I would definitely not expect the pH to go up by 0.25 as was the avg rise reported by Bill.

It's really a guesswork no matter how you look at it. Personally, I prefer to err on the lower side of additions rather that add too much and then having to correct the other way later. Bill's advice is good - do a cold stabilization test on a sample and that will telly you what if any adjustments need to be made.

Pp

Hi Charles,

AccuVin produces some really easy-to-use testers for specific acid levels in your wine. It's not scientifically accurate to a specific mg/L amount, but they work great to tell you if you've attained a "safe level" (e.g. no Malic) remaining.

Cheers,

David

This is good practical advice Bill. Sometimes the obvious eludes me. I'll try a single bottle to see benefits (if any) before commiting the entire lot. Thanks!