A couple of "newbie" questions.

Kentucky - Q1. Yes. Q2. Tartrate crystals often form in grape wines. The usual procedure is called "cold stabilization", and involves cooling the wine close to freezing for a few weeks, to cause some of the tartaric acid to precipitate out. Those of us in the North generally do this over the winter, by putting the carboy outside for a few weeks. There are other things you can do, but none as simple or effective. If this isn't practical for you, just decant or strain the wine. The crystals do not harm the wine - it's really a cosmetic issue.

Doug

Agreed on both; I have always wondered if the reason a Bordeaux bottle has shoulders is to make it easier to decant and leave things like cream of tartar behind. Not to mention they stack a heck of a lot easier than anything else.

You have to get the wine close to 25F for it to pull cream of tartar fast but long exposure (weeks to months) at higher temps arouind 40F works too, just slowly.

Joe

Thanks all. I will add the Campden tabs (1 per gallon I am told ??) during the next racking. I will put the wine out on the back deck this winter before I bottle it. Temps here bounce around from minus 20's for low to plus 50's for highs in January. Should I shoot for 2 - 3 days in the mid twenties ? Is it OK for the airlock water to freeze ? Thanks again. I really appreciate all the good info I get from this group and its old posts.

A few days in the mid 20's is great, if you get it out there earlier it will help too. You have a big mass to cool. As a point of reference a 6 gallon carboy at somewhere in the 60's took most of the day to get to the mid 20's. Wraps something around them like an old towel to keep the sun off of them, it isn't good to expose reds to sunlight but more than that it will heat them. Shade is better if possible.

Just put the cheapest alcohol (drinking, not rubbing) you have in the airlock and it won't freeze. The mass will shrink a bit more than the container so you don't want it to freeze. You can top it or ignore it if it's only a few days.

Joe

Adding SO2 (campden tablets) before fermentation results in extra acetaldehyde in the product. This means that unless you add even more when fermentation finishes your wine will be susceptible to bacterial attack.

Your SG seems rather high for a finished fermentation. It is possible that the combination of alcohol plus residual sugar has reached the tolerance level of your yeast. During fermentation one molecule of sugar produces two molecules of alcohol. This means that the water activity of your wine decreases (osmotic pressure increases) as fermentation proceeds. With a suficiently high initial sugar content the limiting water activity of your particular yeast can be reached before all the sugar has been fermented and fermentation then dies. I have seen this happen on ferments of over 20,000 litres. A bit embarrasing but addition of 10% water would usually restart the ferment. I did include this in my book on beverage chemistry a couple of years ago.

Bob Molony

I appreciate the info Bob. I am confused though (a normal state for me). If the yeast has "belly'd up" and I now add one half gallon of water to the batch, do I also need to add live yeast ? Or,, if I do nothing, will the remaining sugar just give me a sweeter finished wine ? Best as I can fgure the percent alcohol by volume is around 14 -15%. Thanks again.