Tart Wine

Hi Joe,

You should be fine treating with potassium (bi)carbonate. I do it when the wine is toward the end of the aging process, after cold stabilization. If cold stabilization hasn't reduced the TA to where I want it (judging by taste) I add potassium carbonate to the cold wine (that way there's no foaming) and let it react slowly for a few days or a week. There's no discernable impact on taste if you're only dropping 2-3gm/liter. Any more than that and there might be a taste impact. You have to chill the wine to get the full benefit of the acid reduction. If you're sure that the wine is too tart there should be no harm in doing it now, but there's no harm in waiting either.

Regards,

John

Hi John

How cold should the wine be when you add the potassium carbonate? I have the wine in a cold garage now. Can I perform this at cold stabilization temps or should I bring it in first? How do you stop the process after it reacts for a few days-a week? Do you cold stabilize again afterwards?

thanks

Joe

Hi Joe,

You can add potassium carbonate at any temperature. If you do it when the wine is warm, it will foam like baking soda added to vinegar. If you do it at cold stabilization temperatures it won't foam, but it will take a few days to complete the acid reduction. In either case you have to cold stabilize for about a week or so after adding to get the full acid reduction. You can't stop the reaction- .66 grams per liter of potassium bicarbonate will reduce the TA of the wine by one gram/liter and then the reaction is done. So, you need to add just the right amount by doing trials, or do it in small 1g/l steps. Double check the amount to add because it's different for potassium carbonate and potassium BIcarbonate.

Good luck,

John

You will also need to degas the wine again to get rid of the dissolved CO2. That's best done when the wine is at room temperature.

Tom S