What's Your Opinion of ........ ?

the common methods for lowering tartrates in low pH high TA white wines? Is it okay to have tartrates precipitate out in your bottle of wine? Would your prefer the winery precipitate them out and remove prior to your purchase of that wine? How do you feel about adding stabilizers like carboxymethylcellulose derivatives(e.g CelStab) to the wine before you purchase? Adding stabilizers has become pretty common place in light of the energy costs to cold stabilize with refrigeration. What do you think?

If there has ever been a clickbait title of a thread, this has to be it!

This.

My opinion of … is --------.

Tartrate precipitation is fine.

Dan Kravitz

I think you may have too much thinking time on your hands, Gary.

How do you feel about this - and why?

Cheers

Tartrates in the bottle don’t bother me one bit. But I don’t think that the general public agrees. Way back when I worked the tasting room of a small winery, I addressed this repeatedly from customers that thought there was something wrong with the wine and wanted to return it.

A related question on tartrate. Is there a perceptible difference in taste of a wine where tartrates have precipitated? As I understand it, as the tartrates precipitate out of solution, the resulting solution has less tartrates. Does that result in any significant change in the taste of the wine? Has any one ever done a side by side with the same wine on this matter?

No. That’s not quite right, RB. My understanding:

At low T the equilibrium concentration of largely potassium ions (in human-undetectable form) and tartaric acid that exists at higher T becomes unstable and a certain percentage of K+ will react with tartaric acid to form the potassium tartrate salt that precipitates, restoring the equilibrium at the new concentrations (and I believe a very slight increase in pH). The perceived change in acid and aromatics of the solution due to small decrease in Tartaric acid is again human-undetectable. Chemists? Close?

I feel like I’ve been had

Hot take - my opinion of puppies is that they’re adorable.

I don’t mind them one bit. White wine diamonds are cool, actually.

Don’t mind them either, but if I had a biz pouring wine by the glass I’d avoid pouring by-the-glass wines with them. Can’t count how many times at former jobs customers returned full pours that had tartrates settled in the glass, regardless of how well me or another server or manager explained it to them.

There was a thread on pH vs. TA a while back. And while it sounds like the pH might lower as tartrate crystals form, wouldn’t the precipitation of tartrates itself lower the measurable TA in the resulting wine? Curious to know if that impacts the perception of the wine.

This also brings up another question on the reasons why some producers chose to cold stabilise wines or not. One of the reasons often cited is that cold stabilisation strips out some flavours and aromas. Is there a difference in the chemistry of cold stabilised wines at the winery and ones where tartrates have naturally formed in bottle as a result of being exposed to colder temperatures longer?

Not really but I had just gotten back from the hospital where they tried to stuff me into an MRI machine that was clearly made for elves. Did the magnets have an effect on me I’m not really sure. But back to the topic at hand…it seems to me that a chardonnay that I’ve liked for many years has changed in recent years and does not have the same freshness in the mouth. I’ve come to learn that tartrates that had been precipitated out in previous years is now kept in solution with stabilizers. I myself am okay with “white diamonds” in my wine but I understand for some the negative visual effect it has is a show stopper. My first reaction to adding anything into a wine being made is a negative one so the increase use of stabilizing additives concerns me. Not sure if the taste or mouthfeel of these things is significantly perceptible but I do have my suspicions. A nice experiment would be to have 3 wines made in the same vintage with low pH and high TA where they are 1. no cold stabilization, 2. cold stabilization & tartrate crystals removed, and 3. addition of a tartrate stabilizer. There’s that initial wine impression formed but you also need to see how these differ down the road.

With regards to tartrates the act of precipitation lowers the TA and the “tartrate” solution continually resets equilibrium during precipitation. To my palate there is a noticeable difference in the acid attack of the wine if the grapes were picked at some level of ripeness and went through tartrate precipitation. The only caveat is when the grapes are not sufficiently ripe the malic acid component in wine can be dominating .

One of the reasons that wine producers have moved away from cold stabilizing their wines is that the energy costs to do so are high. Some in colder climates will put their wines outside for part of the winter…in ss barrel or tank of course. That lets mother nature take care of the precipitation. One note is that if you are leaving a wine on lees for a period of time that might put you into a warm period where using mother nature is not feasible. If the winery cold stabilizes and then racks the wine away from the tartrates I would expect the loss of flavors or aromas to be negligible . If in the winery chooses to filter the wine to separate the crystals from the wine then it comes down to what type of filter they used and the affect that might have on the flavors/aroma components.

Thanks you for the explanation. So it seems the critique of cold stabilisation is more about the filtering process to remove the tartrate crystals rather than the cold stabilisation process itself altering the wine.

Rodrigo - Filtering is a common practice and is used for many reasons. Because it is so commonplace it comes down to type of material used for the filter material to have it be as selective as possible. It’s a nice tool to have in the toolbox but you need to be aware of what you’re trying to achieve. To me rack when possible and limit the filtering.

Tartrates precipitating should indicate a minor rise pH. My recollection of CMC is that it can broaden the palate/give the impression of a broader wine.

I’ve seen a few references in the pH shift in this thread so I thought I would clarify. The fulcrum actually swings at 3.65 pH. So, if a wine is cold stabilized above or below this value (or if tartaric acid is added) the pH will actually increase above 3.65 and decrease below it.

AWRI has a nice (short) article on it here: https://www.awri.com.au/wp-content/uploads/2018/11/s2036.pdf#:~:text=When%20tartaric%20acid%20is%20added%20to%20wines%20at%20pH%20above,and%20decreases%20the%20titratable%20acidity.

IIRC CMC doesn’t actually adjust the TA of the wine, it simply prevents the precipitate from forming.