Timing cold stabilization.

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distancerunner

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I would love to know more about the kinetics of crystallization/crystal dissolution, but can't find any useful references. I will probably move my wines outside in a month or so (though they are getting pretty well chilled in my basement already - and the outside temps got down into the upper 20s last night). My still (white) wines could do with losing some acidity; the sparkling base wine needs to be as cold stable as possible, though I also plan to use some non-cold treatment (eg CMC) to inhibit crystal growth. I was thinking of getting some insulated reflective bubble wrap to put around (and on top of) my kegs each morning in an effort to slow down any daytime heating.

Carboys and barrels aren't glasses of soda pop. Doesn't take long for that to come to room temp, even when filled with ice. The liquid in a carboy is a lot of mass. It tends to maintain (more or less) stable temps. Daily fluctuations will budge them a couple of degrees up and down. Not a big deal.

There are some winemakers who believe that daily temperature fluctuation is a good thing. Maybe they've got something. Maybe they're just lazy. If it's lazy, count me in.

If the carboys are in direct sunlight, maybe it's a good idea. That would tend to heat reds a bit quicker. Otherwise it's probably a waste of time, effort, and materials.
 

BarrelMonkey

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Carboys and barrels aren't glasses of soda pop. Doesn't take long for that to come to room temp, even when filled with ice. The liquid in a carboy is a lot of mass. It tends to maintain (more or less) stable temps. Daily fluctuations will budge them a couple of degrees up and down. Not a big deal.
For sure. Way back in my dim and distant past I have a physics degree so at least at one time I knew about things like specific heat capacity...

But if I leave my kegs outside for, say, 2 months, the best I can expect is to cold stab to the average temperature over that timeframe. It can get down to upper 20s at night, but frequently up into the 50s in the daytime. So even if (wine) temperature is only moving up and down by one or two degrees every day, I want to get my average as low as possible. Maybe I will do the scientist thing and keep a log of internal/external temperatures, though that would entail opening up the kegs more than I would like...

(And they will be out of the direct sun - there is a corner on the NW side of my house that gets no direct sun in the winter months)
 

wineview

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I was taught to rack the wine before it warmed up. However, I've read that the crystals won't dissolve easily upon warming. I don't know which to believe, so unless someone provides evidence that it's not necessary, I'd go low risk and rack the wine while cold.
And what time frame do you leave them outside? I’m in upstate NY and we are in the low 30’s to mid 40’s. A week? Month? Several months?
 

BarrelMonkey

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Probably. Near freezing gets the best results, but anything below 50 will produce at least partial results.
So I was about to say that you need to rack off the tartrates before warming up the wine, but then read several articles saying that tartrate crystals persist, ie do not redissolve easily. I'm leaning more towards what @distancerunner said above, ie that there is limited value in trying too hard to prevent the daily cold stab temperature fluctuations...
 
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