Cold crash?

[zadvocate]

I just checked my cab that's been in a car boy for almost 3 months right after primary. The pH came in at 3.18 and the TA at 7.5. I had planned to rack off the sediment this weekend and continue to Oak it, should I cold crash it for a week or two first to get the pH up? Or rack this weekend and then go crash it?

 

[Julie]

I would rack first

 

[Johny99]

I'm with Julie, rack it. Has it been through Malo? Is it complete? I'd do that first to adjust acid, then CS, then think about adjusting as a last resort.

 

[zadvocate]

Yes it has been through MLF

 

[zadvocate]

I added 9 grams of pot BiCarb to 6 gallons and put it in the refrigerator. I'll check it out in a couple of days

 

[Johnd]

I added 9 grams of pot BiCarb to 6 gallons and put it in the refrigerator. I'll check it out in a couple of days

Remember that cold stabilizing a wine with a pH below 3.6 will increase acidity, i.e.: lower the pH, not raise it. What was the effect of the K bicarbonate? If it didn't raise your pH above 3.6, the fridge time could have the opposite effect that you are trying to achieve.

 

[zadvocate]

Thanks, I just pulled it out of the fridge was only in there for maybe 20 minutes the pH is now at 3.3 and the TA 8. so it did go up a little. I will just leave it sit in the closet and see what happens. I thought the cold would help bring it down. Do you think I will see a reduction in the acid? Or is there something else I need to do?

 

[zadvocate]

Correction the pH is like 3.25. I think I'm just going to leave it all alone for a while

 

[zadvocate]

I;m really confused. i added pot Bicarb to raise PH and lower TA. I have been reading all over the net that you must cold stabilize after adding Pot bicarb. I have also read the wines with ph under 3.65 that are cold stabilized may have the ph go down. I don't understand how you use pot bicarb to raise ph and it say that you need to cold stabilize which would lower pH?

 

[Stressbaby]

This is my understanding:

The cold stabilization is needed after KHCO3 additions due to the fact that it is a POTASSIUM salt. Wine diamonds are POTASSIUM bitartrate, KHT. With the extra K+ additions, the wine is no longer temperature stable from the point of view of the K+. You need to drop some KHT out with cold stabilization.

Again, the pH effect of that varies. If you are able to raise the pH to 3.65 (with the KHCO3), the subsequent cold stabilization theoretically would have little to no effect on the final pH of the wine.

Also, by my calculations you are well under the KHCO3 limit of 1g/L. Link

 

[zadvocate]

Yes I noticed that after using fercalc and added another 10 g. I was reading the winemakers answer book and it just says to add it and let it sit for 6 to 8 weeks. It doesn't mention cold stabilization.

 

[Johnd]

Yes I noticed that after using fercalc and added another 10 g. I was reading the winemakers answer book and it just says to add it and let it sit for 6 to 8 weeks. It doesn't mention cold stabilization.

NEVER add as much as you calculate!! Use half your calculation, stir well, and let it sit for a while, recalculate based upon where your new pH is, and again, use half, and so on until you get where you want to be.

There are limitations with K bicarbonate, as it only removes tartaric acid (I think I'm recalling correctly). So, it will only lower pH until all of your tartaric is gone. I've read that it not be used if you are trying to move your pH up more than .2 or .3 units, and I've always used it within those limitations.

 

[Stressbaby]

I've read that KHCO3 reacts with malic, but the problem is KHM is soluble in wine and doesn't really precipitate.
Moot point in this case because he has no malic, the wine has been through MLF.