Chambourcin wine, next steps, sour taste

[kartracer088]

I still have 8 gallons that has not been cold stabilized, maybe I should rack off a gallon and try adding tarteric acid to lower the pH and then do the cold stabilization.

The part I don't understand, is I thought CS was for removing tartaric acid, and it seems counter to adding it right before.

 

[Tnuscan]

I still have 8 gallons that has not been cold stabilized, maybe I should rack off a gallon and try adding tarteric acid to lower the pH and then do the cold stabilization.

The part I don't understand, is I thought CS was for removing tartaric acid, and it seems counter to adding it right before.

Yes, it sounds strange for sure. Even after adding the tartaric acid (and chilling) you have to be careful, because as it(potassium tartrate ) starts to settle out, it might raise the pH (less acidic). This is why you will need to keep an eye on it during this process. There is a certain area around 3.65 that this heads toward the opposite of what your wanting. Around this 3.65 area, the change is less dramatic, as it gets a few hundreths past this in either direction, the change is more noticeable.

I would just use the gallon that you have been using, you should still be fine by doing so. It will just take more tartaric to lower the pH now. This is why I suggested using a liter, by using a liter the measures will be easier to understand/calculate, and the loss, if a mistake is made, will be less.

 

[kartracer088]

Thank you for the article on pH, it was very enlightening. Time to get some tartaric acid and do some trials.

The article indicated I could also adjust after CS.

"As a guideline, you can assume a 0.1 pH unit increase or decrease for every 1 g/L decrease in TA. The precise amount of potassium bitartrate to be precipitated is hard to control because of temperature and duration factors. Therefore, cold stabilize the wine, measure the TA and pH, and adjust accordingly."

I can see the point of getting the pH as close to 3.65 so it doesn't move drastically during CS.

 

[Tnuscan]

Thank you for the article on pH, it was very enlightening. Time to get some tartaric acid and do some trials.

The article indicated I could also adjust after CS.

"As a guideline, you can assume a 0.1 pH unit increase or decrease for every 1 g/L decrease in TA. The precise amount of potassium bitartrate to be precipitated is hard to control because of temperature and duration factors. Therefore, cold stabilize the wine, measure the TA and pH, and adjust accordingly."

I can see the point of getting the pH as close to 3.65 so it doesn't move drastically during CS.

Cold Stabilization: This procedure is usually performed after fermentation, when the weather is slightly below freezing. Putting the wine into a refrigerator is an alternative. In either case, it also helps to "seed" the wine with cream of tartar crystals in the amount of 2 - 6 g/l. Do bench trials to determine the optimum amount to be used. Cold stabilization will not work if the pH is too low, less than 3.2, because the malic acid content will be higher than the tartaric acid content; and malic acid does not precipitate its salts as does tartaric acid. As well as reducing acidity, cold stabilization reduces the probability of tartrate precipitation when the wine is chilled before serving. Prior to cold stabilization, the pH should be below 3.65, otherwise any precipitation of potassium bitartrate will lead to a decrease in both the pH and the TA, possibly necessitating the addition of acid prior to bottling. Conversely, if the pH is much above 3.65, the pH will increase.


Might want to make a more acidic Chambourcin this fall and blend the two, will probably get better results.

 

[Tnuscan]

Thank you for the article on pH, it was very enlightening. Time to get some tartaric acid and do some trials.

The article indicated I could also adjust after CS.

"As a guideline, you can assume a 0.1 pH unit increase or decrease for every 1 g/L decrease in TA. The precise amount of potassium bitartrate to be precipitated is hard to control because of temperature and duration factors. Therefore, cold stabilize the wine, measure the TA and pH, and adjust accordingly."

I can see the point of getting the pH as close to 3.65 so it doesn't move drastically during CS.

"As a guideline, you can assume a 0.1 pH unit increase or decrease for every 1 g/L decrease in TA".

Maybe,??, I've read that some pH units/measures don't move as expected. I really don't know if it will or not.

And, I think you would want to be a little under 3.65 to be safe.(??)