Comments on: Bubbles & Ice

By: Swerv

Swerv — Thu, 19 Nov 2009 05:48:02 +0000

cold stabilization may not work for us since the initial pH (before cold stabilization) is above 3.65. We can talk about this tomorrow. Maybe we just leave it alone and be sure to sulfite it properly after the MLF is done

Have a good evening.
Swerv

By: Swerv

Swerv — Thu, 19 Nov 2009 05:34:10 +0000

I’ve been thinking more on our final pH numbers. A rule of thumb is that for 1g/l of tartaric acid added, you should see a 0.1 drop in pH. This is a rule of thumb but keep in mind that different grapes have different buffering capacities. We added 2.42g/l (for 36 gallons) or 2.13g/l (for 30 gallons) of tartaric acid, so we should have expected a drop in pH in the range of somewhere between 3.63 – 3.59. We probably did see that drop (your measurement of 3.41) which may have been ~0.1 low compared to if Vinquiry did a reading. But then we pressed the heck out of must and perhaps got a fair amount of potassium leeching from the grapes, thus bumping up the pH back up. Now the MLF will result in rise in pH to between 0.1 – 0.3 … if it’s still a concern at that point we can adjust with tartaric acid again and then do cold stabilization to get a drop in the TA. Thoughts?

By: Swerv

Swerv — Thu, 19 Nov 2009 05:03:37 +0000

Hi Niels:
Here’s a decent read on pH and TA
http://www.brsquared.org/wine/Articles/pH.htm

Maybe the amount of pressing we did resulted in an increase in the pH … but man we needed the juice.

Swerv