Adjusting PH AFTER fermentation, refresh my memory

[geek]

My friend recently bought a Lodi Gold juice bucket and the LHBS person stated they come pre-balanced but no yeast added.
PH was high in the ~3.9x
Muscat Canelli juice bucket from Lodi Gold.

Juice was fermented as is.

After fermentation the PH is in the ~4.0x range or so.

Would you use tartaric acid to lower the PH a bit or acid blend?
How much?

I hope this adjustment AFTER fermentation will not throw off the balance completely...

 

[acorn]

Yes, I would say you could add tartaric acid post fermentation, but don't overdo it either. Usually 0.15%, and at most 0.3%, TA adjustment could help your wine. Also note, the later you add it in the process, the more unpredictable results you may get, so if you missed the adjustment prior to primary fermentation, try to do it ASAP.

As for the amount, a lot depends on the style of wine you want to end with, and with the volume you have. Try using this tool to figure it out.

http://www.winebusiness.com/tools/?go=winemaking.calc&sid=5

And lastly, let your taste be the guide. You may not even like to add all of the calculated amount, rather add it in stages and taste, just to make sure you don't overdo it.

 

[geek]

Thanks.

How about acid blend instead of tartaric acid?

This are is a bit gray for me still...learning daily...

 

[acorn]

While not the best option in grape wine making, at this point after fermentation in particular acid blends may do more harm than good. Specifically, citric acid that is included in the blend can often metabolize to other compounds like acetic acid (vinegar) and contribute to volatile acidity, which is probably not what you would want. Malic acid, too, can pose problems if/when maloactic fermentation is involved (that is when you expect to taste no bitterness due to malic acid, but you will because the one they put in the blends will not convert into lactic acid).

So, the bottom line, it gets tricky with blends. Using pure tartaric acid will be more advantageous not only because it is the main acid in grape wines, but also because you have some room for experimentation (e.g. you can either add it, or partially remove it by precipitation as potassium bititrate during cold stabilization).

As a last resort one can use the blend, but be prepared for potential surprises, although since fermentation is already complete, you can just get tartaric acid, even if you order online, since 2-3 days in shipping will not make much difference at this point.

 

[geek]

Thanks. I have tartaric acid as well and will use that.

 

[Turock]

I agree with using tartaric acid to adjust. Be sure to set up several bench trials at different PH's and taste them. Go with the best tasting one instead of shooting for any target.

 

[geek]

Ok, racked into plastic bucket to degas, measured PH ~4.21

Added like 1/4 tsp of tartaric acid and then 1/4 tsp again, it is now ~4.02

Measuring TA now to be sure and calibrating my PH55 ....

UPDATE: calibrated PH55, and re-measured PH=4.02

TA around .67 or so.

For TA I used 15ml of wine in a glass container, then added increments of 1ml of 0.2N solution, I went up to a bit over 6.5ml of .02N and PH wasn't in the 8 range yet, so over shoot up to 7ml and PH went past 8.2 at 8.45

So TA has to be around .67

Should I leave as is and NOT any more tartaric acid, leave PH at 4.02?

..

 

[Boatboy24]

Definitely use the tartaric. And read these. Adjust halfway to your target first. Then test and taste. If further adjustment is required, go half again.

http://morewinemaking.com/articles/Acidifying_must

http://morewinemaking.com/articles/complete_must_adjustment_pH_TA_Brix

 

[acorn]

Should I leave as is and NOT any more tartaric acid, leave PH at 4.02?
.

What is the volume of your wine? Do you know how many gramms or ounces are in the total of 1/2 tsp that you added?

You could probably add a bit more, but honestly, I think you should go with the TA measurement, which seems to be fine. You will only have to pack your wine with more SO2 in the end, otherwise you may throw it off balance by trying to get your pH down to 3.6 or less.

 

[geek]

It was a 6gal juice bucket but now I have a 5 1/4 gal.

Well, I ended up adding about maybe 23gr of tartaric acid (like over 4 tsp?) and the PH finally came down to 3.80 exactly.

I looked at a table I have which indicates a white wine can have a TA of 0.7~0.75

So, I didn't check the TA again but left it with a PH=3.80

Stirred really well and added 1/4 tsp k-meta, racked back into 5gal carboy and placed air lock.

Wish me luck....

 

[acorn]

Okay, that's sounds reasonable. You adjusted your acid about 0.115 (if I am not miscalculating something), which is less than maximum recommended rate of 0.15. I hope it tastes alright too. And yes, definitely, good luck with it.

 

[deRicardo]

Okay, that's sounds reasonable. You adjusted your acid about 0.115 (if I am not miscalculating something), which is less than maximum recommended rate of 0.15. I hope it tastes alright too. And yes, definitely, good luck with it.

Yes, that's most important question, "How does it taste?"

 

[geek]

The wine is dry at 0.996 and I like whites semi sweet but took a sip and I think it did balance and tastes not as flabby as before, so all in all it is better.

I'm going to leave alone for a couple weeks and then will add sorbate again, back sweeten and then super kleer.



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