Just did final (hopefully) rack of grape wine made from home grown grapes. SG is .994,, wine clear with no off odors. Hope to bottle this week. When we finished siphoning the 5 gal carboy to a clean one we found the bottom was covered with a whitish/pink crust. I flushed it out in the sink to check it. It was crunchy and about 1/8th inch thick on the bottom of the carboy. No crust was present on previous rackings. Any ideas ?? Do I have a problem ??
How long did you have it in that carboy? What was the temp that you held it at? Did you cold stabilize? I am thinking that it is tartrate crystals.
You don't have a problem. You have potassium bitartrate (cream of tartar) crystals.
It's perfectly normal for excess bitartrate to drop out of wine when it gets cold(er).
Tom S
The wine (with crust) was in the carboy for 6 weeks. The temp was 65F + or - 5 degrees for this period. I began with a juice only must containing 5 gal fresh pure juice + 1 gal water mixed with 4 pounds of cane sugar. Water was from my deep well (untreated and has high mineral content. I have to soften the house supply) Wine was first racked at SG 1.030 on Aug 24,05 again on Sep 21 and again on Oct 15. SG 0.994 achieved on Sept 03. I added Campden tabs (1 per gallon) on the Sep and Oct racking. For this last racking I added 1/2 tsp per gal sorbate plus 1/4 tsp per 5 gal Campden tab. I plan on adjusting flavor/sweetness with frozen pure Welch's grape concentrate before bottling this week. The Welch's ingredient list shows citric and asorbic acids were added. Advice welcome and appreciated.
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