Tartrite Crystals in my wine

[Chillywack]

I switched from kits to all juice making my wines. My first batch was a Chardonnay from Chile, not tartrites, filtered before bottling. My next 2, a Pinot Noir from Chile, and a gewurztraminer from California, I did the same thing filtered before bottling(Pinot Noir bulk aged for 1 year, gewurztraminer bulk aged for about 8 months before bottling). They both look and taste great. However, I rec'd a wine rack for christmas to store my wines and the other week when I took one out to drink, I noticed the crystals. Now I am thinking since it got colder out my storage area where I keep them probably is around 55 degrees F and since I used to store them on their side in boxes is wasn't an issue but on a rack where the bottles probably cooled a little is what caused. I know cold stabalization would have helped prior to bottling but is there a way to cold stabalize an entire carboy with out using a fridge? Does any cold stabalize before bottling? How do the commercial wineries prevent the crystals from showing up? BTW, the wine still tastes great to me. Thanks.

 

[cmason1957]

How do Commercial wineries keep it from happening? They cold crash giant vats of wine. M any of them have glycol jackets and chill the wine down to nearly freezing for a couple of weeks.

 

[Chillywack]

Thanks

 

[user 36973]

How do Commercial wineries keep it from happening? They cold crash giant vats of wine. M any of them have glycol jackets and chill the wine down to nearly freezing for a couple of weeks.

Be sure you add the majority of your potassium (Sulfites, sorbate, bicarb) to the wine prior to cold stabilizing.

I chill the wine to 26-28F and pitch in potassium bitartrate crystals (aka cream of tartar) to seed the crystal formation. I measure the wine conductivity for the next several days and end stabilization after it the reading is constant for a day. Overall, I can get the wine cold stabilized in 5-7 days.

 

[keverman]

Question: is the cream of tartar just the regular grocery store stuff, or is there something different about it? I've never done the seeding thing before. Any tricks to adding it?

 

[user 36973]

Yes, you can use the stuff from the grocery store. It doesn't take much, only about 0.1g/L or about 1 tsp per 5 gallons.The only tricks are that you must first chill the wine to a temp where it will produce tartrates (as close to freezing as you can get). Then sprinkle the dry cream of tartar onto the top of the wine and lightly stir around the top. Don't dissolve it first in water because the whole point is that you want it to remain as small crystals in the wine to act as seed crystals for the large crystal formation. Then leave the wine at cold temps for another few days to a week or so to let it do its thing. You should see crystals dropped to the bottom of the carboy, if you are using glass.

 

[keverman]

Thank you!!

 

[Ajmassa]

Be sure you add the majority of your potassium (Sulfites, sorbate, bicarb) to the wine prior to cold stabilizing.

I chill the wine to 26-28F and pitch in potassium bitartrate crystals (aka cream of tartar) to seed the crystal formation. I measure the wine conductivity for the next several days and end stabilization after it the reading is constant for a day. Overall, I can get the wine cold stabilized in 5-7 days.

I just finished cold stabilizing for about 3 weeks. Wish i read this beforehand. Very informative - as always @jgmillr1

So why is it crucial to add your K products sulphites/sorbate/bicarb to the wine prior to CS? is that because if adding afterwards then it could result in more tartrate fallout?

Also what ‘conductivity’ are you measuring to determine when to end the CS? Not sure what you mean by this. my only determining factor is visually monitoring the tartrate fallout. And I decided to end the CS after it seemed like there was no more crystals forming. Is there an actual accepted method to determine the endpoint?

 

[user 36973]

So why is it crucial to add your K products sulphites/sorbate/bicarb to the wine prior to CS? is that because if adding afterwards then it could result in more tartrate fallout?

Yes, changing the pH will change the concentration of bitartrate ions so any pH adjustments need to be made before CS. Same goes for any potassium additions. Cold stability is only achieved at a given pH, potassium concentration and for a minimum temperature. If you significantly alter the balance of potassium or bitartrate in the wine, it will become unstable again and may form crystals.

Also what ‘conductivity’ are you measuring to determine when to end the CS?

The conductivity measures the electrical conduction of the wine. As crystals form, there are fewer ions (potassium in particular) and the electrical conductivity drops. You can buy a meter on amazon. This is the typical way to monitor the progress of CS. Be aware that conductivity is strongly sensitive to temperature, so allow the wine sample to reach room temp before trying to measure it.

 

[user 36973]

Is there an actual accepted method to determine the endpoint?

I looked through a few books I had on making wine and the home winemaking books (e.g. Cox and Pambianchi) don't discuss monitoring cold stabilization and deciding on the endpoint. However, a more technical book that does cover the topic is Roger Boulton's "Principles and Practices of Winemaking". Here are are couple pages where they discuss monitoring the conductivity as the "Davis Conductivity Test".

 

[David Violante]

Thank you @jgmillr1 for your explanation... as I was searching for the Davis Conductivity Test, I came across this super article on cold stabilization from Penn State Extension that discusses some of the theory, methods, and detection techniques.

 

[winemaker81]

@David Violante, that's an interesting article, thanks for sharing. @jgmillr1, I had not heard of seeding before.

It's not always possible for home winemakers to get a wine down to 26 - 28 F and keep it there for a week. When I lived in Upstate NY, my porch was typically 32 to 36 F in the winter, so I put carboys on the porch for 7 to 10 days, and never had crystals form in the bottle. While this temperature range is not going to produce as much result as 26 to 28 F, it worked sufficiently well. Note: I made white wines using Finger Lakes grapes, which were typically high in acid -- I cold stabilized to reduce overall acid, not specifically to prevent crystal formation, which was a beneficial side effect.

Rack the wine while cold -- don't let it warm up first or some of the crystals will dissolve again.

 

[user 36973]

It's not always possible for home winemakers to get a wine down to 26 - 28 F and keep it there for a week.

I've also done the hard freeze method in the past for 5-gal batches that could fit in a chest freezer. It's handy to keep a couple of the 5-gal plastic containers some juice is shipped in around for that. Freeze the wine solid and you will guarantee it's cold stabilized! There are also chest freezer temperature controllers you can buy on amazon.

 

[winemaker81]

Freeze wine? A friend left a case in his car overnight and it froze -- not enough to burst the bottles, but the insides were slush. The wine developed a nasty taste.

An acquaintance had an old refrigerator that he removed all shelves from -- it was wide enough to hold 2 carboys. IIRC, he set the temperature just above freezing (33 F). This needs to be an over-n-under fridge, not a side-by-side.

 

[user 36973]

Freeze wine? A friend left a case in his car overnight and it froze -- not enough to burst the bottles, but the insides were slush. The wine developed a nasty taste.

Interesting, I wonder if the corks had pushed on the bottles? I don't recall any unusual flavors with the 2 types of wine (traminette and concord) that I'd frozen but it was a long time ago. I now use glycol chilling on jacketed VC tanks though there is a minimum wine volume needed to reach the jacket.

Oxidation seems to be the biggest risk when the wine gets cold and may be exposed to headspace or air. I'm somewhat paranoid about oxidation and let the wine fully warm to room temp before racking off the crystals. It is possible some crystals may redissolve in the warmed wine, but seeing how rinsing with hot water doesn't readily dissolve the crystals I'll take that over oxidation.

 

[winemaker81]

I searched on it, and several sources state that freezing wine may result in a slight change in taste. My experience was not "slight", although I'm wondering if the variety made any difference -- I can't recall for sure what the wine was (maybe Niagara), but knowing the friend, it was a somewhat sweet French-American hybrid made in the NY Finger Lakes.

 

[user 36973]

Maybe it's best not to freeze it then. LOL, if the wine was Niagara I personally would find it hard to tell if it had gone off! I've never liked Niagara and mixing in OJ makes it just barely drinkable.

 

[keverman]

Yes, you can use the stuff from the grocery store. It doesn't take much, only about 0.1g/L or about 1 tsp per 5 gallons.The only tricks are that you must first chill the wine to a temp where it will produce tartrates (as close to freezing as you can get). Then sprinkle the dry cream of tartar onto the top of the wine and lightly stir around the top. Don't dissolve it first in water because the whole point is that you want it to remain as small crystals in the wine to act as seed crystals for the large crystal formation. Then leave the wine at cold temps for another few days to a week or so to let it do its thing. You should see crystals dropped to the bottom of the carboy, if you are using glass.

So I seeded with cream of tartar (Marquette wine, pH 3.54) and used 2 teaspoons for 6.5 gallon carboy. Temperature was at 23 degrees and still is. That was 6 days ago now. What should I expect to see? I see some small white flecks sticking to the side near the bottom. I pulled a sample, with a thief, warmed it up to room temperature and the pH has not moved. I did once put a different carboy out in the winter for a month, and it did not develop crystals, but I also had not contact seeded that one. Is this wine just stubborn? I can expect the pH to shift a little, correct?

 

[user 36973]

That should be plenty of bitartrate and the temp is plenty low too. You should end up with crystals dropping to the bottom of the carboy or forming on the sides of the carboy. The amount of crystals you get depends on your potassium in solution. If you're not in a rush, I'd give it another week or so at low temp. The pH may decrease a little as the crystals fall out but it is the TA drop that will be more easily noticed. I've not had trouble with Marquette before. Last fall it left crystals in my tank at room temperature after fermentation.

Are you trying to cold stabilize to lower the TA or because the wine will be served cold after it's bottled? For my dry reds, I'll do a quick cold stabilization just to drop the TA but I'm not actually concerned with it being fully cold stable. However, if it is for a rose wine that I'll fridge and serve cold, then I'm much more careful to ensure it is cold stable.

 

[winemaker81]

@keverman, we got so focused on the basic question "how do I prevent crystals from forming?" that we forgot other important considerations.

First -- cold stabilization may not precipitate tartrate crystals. Crystals form if the reduction in temperature causes tartaric acid to be over saturated. If it doesn't, crystals will not form.

Wines include tartaric, malic, citric acid, plus other acids, and pH is affected by all. A low pH may not indicate tartaric is high, although to the best of my knowledge, it typically is.

Two -- not all wines need cold stabilization. If the wine tastes balanced, e.g., the acid is not sharp, the wine probably doesn't need cold stabilization.

The wines I cold stabilized were Finger Lakes NY white wines, which were very high in acid, often producing an unpleasantly sharp taste. My wines dropped crystals 100% of the time, and the reduction balanced the wine and provided clearing as a beneficial side effect.

I purchased California Sauvignon Blanc in October -- I won't cold stabilize as the wine does not need it -- it tastes fine as-is.

If the wine tastes fine and the point is preventing crystals? Bulk age at 55 F. If the tartaric becomes oversaturated, it will form crystals. The wine should not form crystals after bottling, and chilling the wine prior to consumption shouldn't be long enough to form crystals.