Wine diamonds and carboy aging.

[Sipper]

Years ago I would follow the guidelines for bottling and aging, adding all the chemicals as prescribed. Now that I’m back at winemaking again, and have decided to age my wines in the carboy, without the additional fining agents/chemicals,,, my question is: Approximately when,, during the aging process can I expect wine diamonds to drop? My past experience when aging in the bottles always produced diamonds which didn’t really bother me. But if I can avoid them with carboy aging I’d be happier since I give bottles of wine as gifts occasionslly.

 

[Johnd]

Years ago I would follow the guidelines for bottling and aging, adding all the chemicals as prescribed. Now that I’m back at winemaking again, and have decided to age my wines in the carboy, without the additional fining agents/chemicals,,, my question is: Approximately when,, during the aging process can I expect wine diamonds to drop? My past experience when aging in the bottles always produced diamonds which didn’t really bother me. But if I can avoid them with carboy aging I’d be happier since I give bottles of wine as gifts occasionslly.

At room temps, you may never see them, but as you lower storage temps, the incidence will increase. Store your carboy wine at, or slightly below, the temps your bottles will be kept at. You’ll drop all of your diamonds in the carboy, not in the bottles.

 

[photoguy]

I agree with the above. When I leave the carboys on the concrete floor instead on the counter above the wine will most often drop out the crystals.

 

[CDrew]

I have a question about the potassium bitartrate crystals-do they redissolve in the wine when it warms back to "normal" cellar temps? Or is the precipitation a one way street? I'm asking because if they re-dissolve, you'd have to get the wine cold, and then rack off the precipitate. Am I thinking about this correctly?

Planning to mid-winter garage chill my Rose and Sauvignon Blanc. We'll likely have a week in the 40s in early January so that's going to have to do it!

 

[Ike64]

If possible, move the carboys to a location where the temperature will be around 45 degrees for a week or two. This will precipitate the wine diamonds pretty well. I think it's most important for whites because your can see them in the bottle. Lots of wine diamonds also means that there's a lot of excess tartaric acid in the wine.

 

[Juniper Hill]

Generally been an issue for me with more acidic whites. Disappeared now that I cold stabilize these wines in the carboy.

 

[Ike64]

I have a question about the potassium bitartrate crystals-do they redissolve in the wine when it warms back to "normal" cellar temps? Or is the precipitation a one way street? I'm asking because if they re-dissolve, you'd have to get the wine cold, and then rack off the precipitate. Am I thinking about this correctly?

Planning to mid-winter garage chill my Rose and Sauvignon Blanc. We'll likely have a week in the 40s in early January so that's going to have to do it!

I try to move everything to the garage when it gets cold too. I rack afterwards. Although lugging full carboys around the hours is "flirtin' with disaster".

 

[Ike64]

I have an egress window next to my winery. This year, I'm thinking about getting a number of 4x8 insulating foam sheets and building a "box" around the carboys. Then opening the window for a week or two to lower the temp inside the box without freezing the whole basement. (Probably the first step down the rabbit hole in building a temperature controlled room.) Wish me luck.

 

[cmason1957]

@CDrew The precipitation of tartrate is a one-way street the bitartrates are very stable.

@Juniper Hill It isn't that the "problem" has disappeared, it's more that you are causing the fallout to happen and then racking off the results.

 

[Juniper Hill]

@Juniper Hill It isn't that the "problem" has disappeared, it's more that you are causing the fallout to happen and then racking off the results.
[/QUOTE]
I meant that I no longer have wine diamonds forming in bottles when I chill them. You are correct, I've gotten the tartrates to fall out of suspension before bottling.

 

[Juniper Hill]

I try to move everything to the garage when it gets cold too. I rack afterwards. Although lugging full carboys around the hours is "flirtin' with disaster".

Agreed - there is danger in moving around glass carboys. I've had a few mishaps, but no serious injuries. I'm using more plastic these days. I also converted a basement fridge to lager beer and cold stabilize wine which is very close to where I do my bulk aging.

 

[CDrew]

I try to move everything to the garage when it gets cold too. I rack afterwards. Although lugging full carboys around the hours is "flirtin' with disaster".

I have most of my wine in 15.5 gallon kegs or 15 gallon Intellitanks. So I move everything on a hand truck. It takes the anxiety out of the transfer. No way I'm carrying carboys through the house unless absolutely necessary!

And nice Molly Hatchet reference!

 

[distancerunner]

Probably stupid questions.

Does cold stabilization lower the pH or TA?

Will it affect the tartness in the wine?

 

[Jay A]

Fairly certain you can expect a drop in TA post cold stabilization.

 

[sour_grapes]

Probably stupid questions.

Does cold stabilization lower the pH or TA?

Will it affect the tartness in the wine?

@Jay A is correct. Surprisingly, whether it lowers or raises pH depends on what pH you are starting at. IIRC, 3.65 and higher, the pH will go up. 3.65 and lower, the pH will surprisingly go down.

 

[distancerunner]

Does that mean that MLF becomes a necessity when the pH is under 3.65?

 

[Juniper Hill]

Does that mean that MLF becomes a necessity when the pH is under 3.65?

MLF would reduce Malic acid levels, converting to lactic acid instead - can increase pH somewhat. MLF is really a matter of style - great for most reds and some chardonnays. Not generally used with other whites and roses, but there are many that will do MLF on these styles. MLF really smooths out my hybrid reds, as they are pretty acidic. I generally don't do MLF with my hybrid whites, as I'm concerned it would change the fruit character.