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stability problems

Over the past three vintages, I have produced Cab and Shiraz reds from the cool climate region of the Yarra Valley Australia. Last years Cab was treated with Calcium Carbonate to reduce an accidental over addition of tartaric with some success. The wine was bottled after 12 months in barrel with total SO2 of 100ppm and Ph of 3.36. The bottles are now stained internally and the wine is extremely dark There is still some activity as some minor CO2 is evident. Taste is reasonable though. This year's Cab will also require some acid reduction but by comparison only a small amount of about 0.4 grams tartaric per litre. As tests reveal Malo is complete, I am about to rack the wine for the first time. Can anybody assist in methods of acid reduction apart from Calcium, and methods of fining. Thanks Leon

Reply to
Jason
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My first question is, why are you picking underripe fruit? If you let the fruit mature more fully on the vine the pH will come up to a reasonable level, e.g. 3.4-3.5.

Secondly, why the rush to bottle? Cabernet generally needs at least two years aging before it's ready to bottle. During that time it should be racked off the lees a couple of times.

At the end of barrel aging, when you're approaching bottling, you should do some fining trials to "polish" the wine. That will remove some of the excess tannin and floating debris that is now staining the inside of your bottles, as well as improve the mouth feel of the wine. Try a combination of 1 lb/1000 gallons of Kieselsohl followed by 1 lb/1000 gallons gelatin on a sample (750 ml) for openers. Let it settle out and taste it alongside the unfined wine. Still too tannic? Increase the gelatin. Too "stripped"? Reduce the amount of gelatin. Also, consider using a different fining agent instead of gelatin. Try isinglass (~3 oz/1000 gallons). After you've treated the entire lot to a fining regimen that you're happy with you'll need to allow the finings to settle thoroughly and rack the wine at least once to get it away from the fining lees. Don't try bottling straight off the lees or you'll end up with cloudy wine in at least some of the bottles.

Fining is a big subject. I suggest you do some reading. Peynaud's book is very good, and there are others. Good luck, mate!

Tom S

Reply to
Tom S

Leon - Did you cold stabilize the wine? If not that will drop some acid. Try a sample in the frig. at near freezing temperatures for a week and retest. Also freeze a sample, thaw and retest.

Ion exchange can be used to totally remove acid from a portion of wine. Remix the treated wine with the bulk and arrive at the acid content you want. I make wine as a hobby in 5 to 20 gallon batches. I have an interest in things like ion exchange and have a small system that I use. Depending on the size of your winemaking and your interest you could do the same.

But as Tom said...next year let the grapes hang longer.

Bill Frazier Olathe, Kansas USA

Reply to
William Frazier

Reply to
Jason

I don't understand why you added _any_ tartaric! Those are near *perfect* numbers.

Could be, but I find eggwhites (a) not very aggressive and (b) a PIA to prepare and use. Gelatin (with Kieselsohl) is my tannin fining material of choice.

Tom S

Reply to
Tom S

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