TA vs pH

[GeoS]

pH measures hydrogen ions while TA measures total acid. I find that if I adjust based on TA the pH goes off the charts.

Which is more accurate and why? I'm trying to understand how TA vs pH adjustments affect taste.

 

[Turock]

TA is not total acid. It's the acid available to react with sodium hydroxide. Titratable acid.

It's not really possible to say exactly WHERE the PH and TA need to be, especially since TA varies according to ripeness, growing conditions,etc. And because of this, you can't really say there is a lineal relationship between PH and TA.

It's best not to get hung up on numbers here. Adjust until it tastes good to you---then stop, regardless of numbers. As long as your PH is not real high, which would call for inordinate amounts of SO2 for preservation, then I would not worry about where the PH is as long as the flavor profile of the acid is where you like it.

 

[GreginND]

TA adjustments are linear. The amount of titratable protons you add change the number of titratable protons.

pH is not a linear scale. It is a measure of acid strength. And that can be all over the place because every different wine has different components to buffer the acid strength. Adjustments of acid may not be predictable depending on the buffering capacity of the solution.

 

[GeoS]

I understand Titratable Acid is the acid available to react with hydrogen ions. Some use it as an indication of total acid. My question is what does that mean for taste? Some people say to check TA and use the charts and others say to just use pH. I'm trying to establish some coordination between the two. To check TA you can add a base to a solution and measure the volume added until a reaction occurs or it reaches a desired pH, titration method. You can use pH to determine TA so I am looking to see how these are related.

If they are not related then both cannot be used to determine acid levels and one should not be used. But which one?

 

[GeoS]

And yes, pH is logarithmic thus my belief they are not really related.

 

[sour_grapes]

I'm trying to establish some coordination between the two. To check TA you can add a base to a solution and measure the volume added until a reaction occurs or it reaches a desired pH, titration method. You can use pH to determine TA so I am looking to see how these are related.

If they are not related then both cannot be used to determine acid levels and one should not be used. But which one?

For a given wine, they are related (albeit, not simply). But the relationship varies from wine to wine.

 

[GeoS]

I guess I'm just trying to understand if you check TA and make adjustments based on that why even look at the pH and vice versa. And which method is best if either one is better than the other.

 

[Deezil]

If one method was better than the other, than only one method would exist/be commonplace. They both serve purposes.

I find in most instances, that pH relates more to SO2 additions, where TA usually relates more to peoples perception/taste of the wine.

You dont want either one to be too high or too low, but getting them both picture perfect isn't as important as the taste is. That said, I don't find it too hard to get the pH between 3.2-3.4 and the TA between 0.55-0.70 %; that's the 'sweet spot' for me, depending on the particular batch.

 

[GreginND]

pH is the important parameter for controlling spoilage bacteria and maintaining proper SO2 levels.

 

[wineforfun]

I know this has been discussed before, but which piece of equipment will measure TA and PH or do you need two?

 

[GeoS]

Well, at least I know I'm not the only one then. I use pH mainly and go for taste. I do look at TA but if it seems off I just go with the pH. Perhaps some more reading into these two is warranted.

wineforfun, you can get a pH meter from many brewing stores or online. I use a Hanna. It's about $35. For TA you can get a kit. It comes with a base and a reagent. You start with a specified amount of wine, add the reagent, then start adding the base until a reaction occurs. The reaction is a change in color caused by the reagent when the pH hits a specific level. Personally, I do not use the reagent, instead I use my pH meter. I suggest researching titration test or titratable acid. There are many good posts and articles on this site. If you still have questions start a thread or post them here and we'll be glad to help as best we can.

One never stops learning. A good teacher is first and for most a great student.

 

[wineforfun]

GeoS,
Thanks for the info. I know I have asked this before and just never followed up as the wines I was making were fine without the tests. Would like to branch out a little so really need to be able to track some things, ie: PH, TA, etc.

I was thinking there was a Vintemeria sp? machine or something like that that did both. It was around $200. I could be mistaken.

 

[Enologo]

Vinmetrica SC-300 tests PH,TA,S02.

 

[wineforfun]

Vinmetrica SC-300 tests PH,TA,S02.

Thank you.

 

[Deezil]

You can also use a pH meter in the TA determination process, by starting with the same amount of wine, adding the base and then use the pH meter while adding the reagent until your pH meter reads 8.2. Makes it easier to perform on wines that are harder to see the color change correctly

 

[GeoS]

The vinmetrica is nice. Unfortunately the price tag kept me away from it. I just use the pH and the TA kit. The kit is less than $10. Perhaps I would get better results with the vinmetrica. Maybe time to ease my wife into the pricetag...☺

 

[GeoS]

Here's what I have been able to discern. Although TA and pH are related to acid their use is different.
pH is checked and adjusted according to taste.
TA 8s checked and adjusted to ensure the proper amount of SO2 (potassium metabisulfite) in the wine. We add SO2 based on the directions on the can, however using TA brings a science to it. The amount of SO2 needed to prevent spoilage is dependant on the pH. If you want to add the proper amount of SO2 you should check the TA to be sure it is in the appropriate range, see charts.

In short pH is adjusted for taste and TA gives a value which corresponds to a range of SO2 required to prevent spoilage.

 

[GeoS]

https://winemakermag.com/547-phiguring-out-ph

 

[REDRUM]

Here's a noob question: do you need to measure acid (whether TA or pH) before fermentation begins, or is it OK to measure later on in the piece and make your adjustments then?

 

[sour_grapes]

Here's what I have been able to discern.
TA [is] checked and adjusted to ensure the proper amount of SO2 (potassium metabisulfite) in the wine. We add SO2 based on the directions on the can, however using TA brings a science to it. The amount of SO2 needed to prevent spoilage is dependant on the pH. If you want to add the proper amount of SO2 you should check the TA to be sure it is in the appropriate range, see charts.

.... TA gives a value which corresponds to a range of SO2 required to prevent spoilage.

I believe that all the references you make to having the correct TA levels for SO2 should really refer to having the right pH value. The web citation you gave, for example, has a whole section on "The relationship between pH and SO2," and never mentions TA and SO2.