Understanding PH

Newbie question here. I know absolutely nothing about PH levels in wine. In my reading the last couple of weeks here it has been mentioned how important it is to get the PH right "before" fermentation. So,

What should the starting PH level be?
What is the best way to test that level?
How do you correct it (up or down)?
Do post fermentation PH levels need to be adjusted?

I have run a search here and having difficulty coming up with anything.

Educate me, please.

drainsurgeon said:

Newbie question here. I know absolutely nothing about PH levels in wine. In my reading the last couple of weeks here it has been mentioned how important it is to get the PH right "before" fermentation. So,

What should the starting PH level be?
What is the best way to test that level?
How do you correct it (up or down)?
Do post fermentation PH levels need to be adjusted?

I have run a search here and having difficulty coming up with anything.

Educate me, please.

Click to expand...

Shoot for a Ph in the 3.35 - 3.7 for reds, I tend to the lower end, especially with white wines.

Test with a good quality Ph meter for best results.

Up with Potassium Bicarbonate, down with Tartaric acid.

If they are in the range of a good, stable wine, no, but taste your wine and do some bench trials to see how acidity affects your taste perception of the wine.

Johnd said:

Shoot for a Ph in the 3.35 - 3.7 for reds, I tend to the lower end, especially with white wines.

Test with a good quality Ph meter for best results.

Up with Potassium Bicarbonate, down with Tartaric acid.

If they are in the range of a good, stable wine, no, but taste your wine and do some bench trials to see how acidity affects your taste perception of the wine.

Click to expand...

Thanks for the quick response John. Just looked at a meter at Midwest Supplys and it runs about $50 compared to $7 for test strips. Is the meter as accurate as the strips? (maybe more so??) I just started a batch last night so can I test/adjust after pitching as long as active fermentation has not started yet?

In general, do fruit wines need much adjusting?

I'll give this one a go...

Usually wine pH is 3.2 to 3.6 with whites on the lower end and reds on the higher end. There are exceptions - for yucks I've tested some commercial NZ sauv blancs which come in around 3.0.

Best way to test is pH meter, there are many threads that will help you find one.

You correct it down with acid (tartaric, citric, malic, or an acid blend). I have quit using acid blend in fruit wines, I don't like the malic component. I pretty much only use either straight tartaric, straight citric, or a mix of the two.

You correct it up with calcium carbonate preferment, or with potassium carbonate postferment. Better to do it preferment. Postferment K2CO3 doesn't change the pH as much and requires cold stabilization. A wine like blackberry will generally need an upward adjustment to bring the pH into an acceptable range.

At the risk of confusing things, you can also change the pH with cold stabilization by precipitating tartaric acid (this assumes that you have any amount of tartaric acid in the must to begin with). The pH can actually go either way depending on your starting pH so be careful here and research or ask first.

Postfermentation pH and acid levels may need to be adjusted. For my fruit wines, my approach is to move the pH down around 3.5 preferment then "fine tune" with further acid additions postferment. It is way easier to increase the acid/decrease the pH than it is to do the opposite.

The meter is WAY more accurate than test strips.

Second the meter being more precise than the strips! the strips might give you the general number (example: pH of 2) but it isn't good for much more than that, and it is often off. they more or less just tell you if something is basic or acid, and roughly how basic of acid, but not very precise on that.
I still don't use a pH meter, I know I maybe should, but I don't. I test TA with a titration and adjust accordingly.

I test TA with a titration and adjust accordingly.

You might as well have been a Concord Jet flying over at 50,000'

Anyone care to translate? (snails pace please, and barely above sea level)

Sorry! TA=Total Acidy or Total Acid.
Here is an article that will explain it much more eloquently than I will: http://www.eckraus.com/blog/difference-between-ph-and-titratable-acidity-in-wine

TLDR: pH represents how much acid is in a wine regardless of how strong it tastes, whereas a titration measures how strong that acid tastes. However pH is important for the preservation of the wine.

pH is tricky; the lower the number the more acidic it is. It is also logarithmic; a 3.2 pH wine is much more acidic than a 3.9 pH wine.

Besides taste, another important reason to control pH is that the effectiveness of the SO2 is very dependent upon the pH. A 3.2 pH wine requires 26 ppm free SO2, while a 3.9 pH wine takes nearly 4X that amount. I shoot for and adjust to between 3.4-3.6.

TA=Titrateable Acid, which measures the actual amount of acid present per litre.

Step 1. The correct term is "small"" p ,"BIG" H

Ok, I'm starting to understand. I'll go get a ph meter tomorrow. I pitched the yeast just a bit ago as I'm at 23 hours post nutrients. I still have not had a reply to the question: can I still adjust PH even though the batch is started? Let's say I get home tomorrow night (with ph meter in hand) and not much is going on yet as far as an active ferment. Can I still make adjustments a day or two into ferment? There is about 100 oz of Pineapple juice and 2 cans of Welches white grape concentrate in the 7 gallon batch. (and 13# of fruit) Anyone familiar with the tropical blend Dragons Blood recipe? I was surprised that there was no lemon or lime juice in this version. The other unanswered question is, do fruit wines generally need adjusting? Thanks again for all the help.

You can adjust at any time, including post fermentation. If it is a big adjustment during an active fermentation, I would step feed it in, versus doing it all at once.

NorCal is right. I've adjusted after mlf when necessary. However, be careful of big changes during fermentation. Small doses are safest.

Norcal and Johny99, Thanks for the advice. Much appreciated!

Stressbaby said:

The meter is WAY more accurate than test strips.

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And well worth the money. You need accuracy of .02. Used ones are easy to find, just make sure you get a good probe. Automatic temperature compensation is convenient, otherwise be sure to do it.

OK, just received my pH meter from ebay and ran downstairs to test the two I've got going right now. The Tropical Blend (Dragon Blood) is at 3.4 and the Skeeter Pee is at 2.7. Both are done with ferment and both have NOT been back sweetened yet. (and taste like crap I might add, but the DB did too at this stage) I think the Tropical Blend is ok, but the Skeeter Pee needs to be raised according to what I've been told on this thread. To at least 3.3 correct? 3.4-3.6 sounds optimum but 3.3-3.7 is the range?? I'll pick up some Potassium Bicarbonate tomorrow and see what I can do with it.

NorCal said:

pH is tricky; the lower the number the more acidic it is. It is also logarithmic; a 3.2 pH wine is much more acidic than a 3.9 pH wine.

Besides taste, another important reason to control pH is that the effectiveness of the SO2 is very dependent upon the pH. A 3.2 pH wine requires 26 ppm free SO2, while a 3.9 pH wine takes nearly 4X that amount. I shoot for and adjust to between 3.4-3.6.

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OK, this is still a little confusing. Understanding that a lower pH # means it is more acidic. So when "raising" with Potassium Carbonate is to actually "lower" the acidity, correct? Then to "lower" with Acid Blend is to actually "raise" the acidity. Or do I have them backwards.

To clarify, I have two wines going right now that read 2.7 (postferment) and one at 3.1 (preferment) that I just started last night (no yeast pitched yet). They both need to be "raised" with Potassium Carbonate?

The pH number needs to become bigger and the TA number needs to become smaller. Less acid usually gives a higher pH.

Masbustelo said:

The pH number needs to become bigger and the TA number needs to become smaller. Less acid usually gives a higher pH.

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I understand that. I have a wine with a pH of 3.1 that I want to raise to 3.5 (or lower the acidity). Which product do I use? Acid blend or Potassium Carbonate?