Cold Stabilization....

I needed a bit of TA and pH reduction on my St Croix so I needed to "seed" it and cold stabilize it to drop out some tartrates.

My other 66 gallons of wine was okay but I like to cold stabilize them anyway. I think it helps them to clear but more importantly it drops out tartrates now rather than later in the bottles.

My wine cellar is not able to maintain a stable 55 degrees all year. In the summer it "slowly" gets a bit higher to about 65 and then in the winter is "slowly" gets a bit colder to about 45 degrees. With these cold temps in the winter I was getting tartrates dropping out of my whites and a bit on the reds. So, now I do a cold stabilization before bottling to avoid the drops later in the cellar.

I bought a brand new refrigerator last year just for my wine making activities. It gives me the opportunity to freeze fruits until I get around to making wine with them (no room in our two chest freezers ... fruits, veggies, meat, etc. for meals). I still have a 4 gallon pail of Concord "Must" (crushed, destemmed, and with skins) in the freezer that I haven't done anything with. And, of course, it gives me the ability to cold stabilize my wines at low and constant temps.


I can fit 4 carboys in the refrigerator at a time. I can get temps down to as low 24 degrees (without an external regulator) so it does a real good job. The rest of the carboys get cold (but usually not as cold nor stable temp) by "waiting" in our "Arizona Sunroom". I attach a remote temperature probe to one of the carboys to monitor the temps but keep the carboys in plastic tubs just in case. We now have a heated garage so I don't keep them there anymore.

Malolactic Fermentation (mlf) going well

Well, my carboys are doing well in a "cocoon" of warmth. I folded a couple of electric blankets in half and then wrapped the carboys in the folded over blankets. Then I covered them with a couple of regular blankets to keep the heat in.

I set the blanket temp on "medium" and the temps of the carboys were able to maintain 75 degrees with no problems.

The heated garage was already at 60 degrees so it was not much of an increase.

This setup also allowed me to easily access the carboys to stir up the lees and mlf bugs every couple of days. I then purged the oxygen out of the carboy necks with Nitrogen to prevent any potential oxygenation. Looks like I need to upgrade to a larger size nitrogen tank next time. This is using a lot more that I thought... in addition to purging wine bottles and carboys.

Well, here's the Chromatography results. The utmost right column is a test of lactic acid as a reference point. Looks like the St Croix is done (the 2nd from the right column).

The first 7 columns are the Italian juice. Looks like it did not have much malic acid to start with but it still needs a bit more time.

Okay, I guess I'll adjust acid and pH and do a cold stabilization of the St Croix in my new refrigerator ... at about 28 to 30 degrees. I'll "seed" it with a bit of cream of tartar to get things going. So far this wine is looking a lot better than I expected for a hybrid. I'm hoping I will be able to get a TA of about 6+g/l and a pH of about 3.4 after cold stabilization. Not bad for a cold weather hybrid grape wine!