TA Calculation

[back2it]

(75 x NaOH-concentration x ml-NaOH)/ml-Wine = TA

75 is the weight of tartaric acid but most of the wines I make are fruit wines which contain mostly malic and citric acids. Should I be calculating with 64 for malic rather than 75 for tartaric?

Does it make THAT much difference?

Thanks
Ray...

 

[BarrelMonkey]

(75 x NaOH-concentration x ml-NaOH)/ml-Wine = TA

75 is the weight of tartaric acid but most of the wines I make are fruit wines which contain mostly malic and citric acids. Should I be calculating with 64 for malic rather than 75 for tartaric?

Does it make THAT much difference?

Thanks
Ray...

TA is defined in terms of grams of tartaric acid per L (at least in the US), so no I wouldn't change the calculation. (Actually I think some European jurisdictions define it in terms of sulfuric acid?) And for that matter, in the US the TA titration endpoint is defined as pH 8.2 whereas others define it as 7 - though as you'll know if you've done it, the difference between these is usually no more than a few drops of your NaOH titrant.

You may, of course, have to add slightly different amounts of malic or citric acids compared to tartaric in order to make your desired change in acidity (eg raise TA from 4g/L to 5g/L). I'd have to look it up, though I know there are resources to say how much, eg malic acid is equivalent to 1g/L tartaric.

 

[back2it]

Thank you. I wasn't sure if the calculation would change depending on the type of wine and acid type that I was dealing with.

I'm not so much looking at data so I can match my wine to a number, but to ensure a consistent way of recording so that I can see where my wine falls against it. Each attempt is slightly different and adjustments are slightly different for each, but it is getting better (thank goodness).

You may, of course, have to add slightly different amounts of malic or citric acids compared to tartaric in order to make your desired change in acidity (eg raise TA from 4g/L to 5g/L). I'd have to look it up, though I know there are resources to say how much, eg malic acid is equivalent to 1g/L tartaric.

I'm fine with making alterations, I take it in baby steps and I use the following to help my calculations.

1.0 g/L addition of Tartaric acid will increase the TA by about 1.0 g/L and will decrease the pH by 0.1 pH units.​

1.0 g/L addition of Malic acid will increase the TA by about 1.12 g/L and will decrease the pH by 0.08 pH units.​

1.0 g/L addition of Citric acid will increase the TA by about 1.17 g/L and will decrease the pH by 0.08 pH units.​

It's working for me so far but I need to learn to recognise when enough is enough. I think I will have to make my adjustments over several days and let the wine and my pallet rest before I finalise to get a better result.

Thank you
Ray...

 

[Rice_Guy]

The purpose of TA is to be a reference point for how many H+ ions are in your mouth, ie what your taste buds are reacting to. The conversion to tartaric really doesn’t matter. What matters is that you speak the same language as others. ,,, Consistency of what the flavor impact is.

Yes sulfuric acid is the calculated acid in Europe. If you are talking to someone there it would be worth converting all numbers to sulfuric.

 

[back2it]

@Rice_Guy It is mainly your explanations and particularly your graphs that guided me on this path. I am trying to build my processes to help me understand the particularities of my creations in the hope that it will allow me to create something that I am truly proud of. My creations have already improved leaps and bounds by reading and asking questions on this forum and some of them are actuallay drinkable now.

Thank you

I also believe that this improvement will allow me to extend my life significantly, after all there are samples in the British Museum that are over 200 years old because they have been preserved in alcohol.

Ray…