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…

 

[Rice_Guy]

My creations have improved leaps and bounds by reading and asking questions on this forum and some of them are actuallay drinkable now.…

Oxidation is the number one reason for loss of fruity aromatics. Using old technology tannins are antioxidants. ,,,, I really like astringent apple tannin and put a few percent crabapple in many non-tannic juices. England has many historical tannic apple varieties.
Some folks I know who retain flavor exclude air with CO2 or nitrogen and also run high on the ppm metabisulphite.

 

[back2it]

I have yet to progress to measuring sulphites, it is on my list of things to learn. I just dont want to get into too much at once, it creates confusion and detracts from my focus.

 

[BarrelMonkey]

I have yet to progress to measuring sulphites, it is on my list of things to learn. I just dont want to get into too much at once, it creates confusion and detracts from my focus.

Understood, it's like learning to drive - at first there are so many things to pay attention to!

I know many people manage SO2 without measurement (and it is a complicated subject - I certainly don't claim to understand all the nuances). But I think it's worth learning, and if you can measure SO2 (and adjust based on the data) it will improve your winemaking.

As an example - Today I measured SO2 levels in my 2024 white pinot noir. I have 3x7gal carboys which came from 2 separate fermenters using 2 different yeasts. So one carboy is from QA23, one from BA11 and the third a blend of the two. My first dose of SO2 was added to the fermenters prior to racking off gross lees. Curiously, the two 'single yeast' carboys have a decidedly pinkish hue whereas the blend is clearly white wine. The SO2 results: 11-12ppm for the single yeast vessels, >40ppm for the blend! It seems that when I added SO2 to the fermenters it didn't mix evenly, so I most likely had a gradient of SO2 concentration and of color pigments in each fermenter. I adjusted SO2 in the two single yeast carboys and I am sure they will drop some of that pigment as they age over the next few months.

BTW was it you who mentioned a company selling a 'SO2 hydrometer'? If so did you ever get any useful information from them - it sounded pretty fishy to me...

 

[back2it]

@BarrelMonkey Yes, it was me. To be honest the cost isn't too much but the reason I didn't get it is because I was unable to find any information other than on thier website, and I didn't get any information from my request other than the answer "it tests SO2". I mean, unlike hydrometers, there isn't 100 you tube videos tell me how to use one.

I will probably buy one when I am able to test SO2 levels and verify that it works (or not), but without being able to it's pointless for me. On the other hand if it does work, then it's well worth the money, just no way for me to know at this time.

Ray...

 

[BarrelMonkey]

@BarrelMonkey Yes, it was me. To be honest the cost isn't too much but the reason I didn't get it is because I was unable to find any information other than on thier website, and I didn't get any information from my request other than the answer "it tests SO2". I mean, unlike hydrometers, there isn't 100 you tube videos tell me how to use one.

I will probably buy one when I am able to test SO2 levels and verify that it works (or not), but without being able to it's pointless for me. On the other hand if it does work, then it's well worth the money, just no way for me to know at this time.

Ray...

Honestly, it sounds like a scam to me. I think your money would be better spent on a burette and flask so that you can run titrations yourself, like most wineries do.

 

[back2it]

I think your money would be better spent on a burette and flask so that you can run titrations yourself, like most wineries do.

Ordered.
I received the burette yesterday, the rest of the kit should arrive this week sometime. I ordered this for my TA calculations as I always press too hard on the syringes and add too much NaOH, but I can also use it for SO2 when I am ready.

I have to say they were super paranoid about packaging; the inner box was about 5cm and the outer box was 30cm (2" and 12") filled with air cushioned gubbins. It got here in one piece, and for such a fragile piece of equipment to get through a parcel distribution system was good work.

I do have a further question about TA though. Maybe this is for @Rice_Guy because it's his data I was looking at. My question is that when I test for TA, I get a reading of, lets say 6, but rice_guy's charts that I have seen show TA at 0.3~2.2, why?

Thanks
Ray...

 

[BarrelMonkey]

There are two ways to report TA, as g/L or as a percentage (w/v), which is 1/10 of the g/L number (eg 6g/L would be 0.6%). I prefer g/L as it seems more intuitive (literally, equivalent grams of tartaric acid per litre), but both are used.

 

[back2it]

Clear

Thank you

 

[Rice_Guy]

As barrelMonkey noted it is “what language are you talking?” Percentage / or per 1000 ml.
In the world of flavor there are lots of combinations that work, for example a soda might be formulated to pH 2.0 which balances out at about 0.2% TA. Or I live where northern hybrids grow so I am stuck with high starting TA and balance to a higher back sweetening level like 1.015. Tannin magnifies acid response so might also balance at what seems to be a higher gravity. ,,, this is cooking, an art.

 

[back2it]

I'm not really worried what "language" just as long as it’s consistent. I will probably use the percentage as it seems that most here use that scale, but it’s not a problem to translate.

I do get your cooking analogy it’s just that I can’t cook for toffee, and I failed art at school (Math Major), so I have been using a recipe/method and brute forceing my way through hoping to “get the feel”.

My creations ARE getting better and it isn't all based on numbers. I have been making small 1 gallon batches as I didn’t feel confident enough to risk wasting money on a 5/6 gallon batch, but now I do. I am just about to bottle 70 ½-bottles which should hopefully take me out of the gallon-to-gallon existence.

Upwards and onwards.....

Thanks
Ray...

 

[TurkeyHollow]

@BarrelMonkey Yes, it was me. To be honest the cost isn't too much but the reason I didn't get it is because I was unable to find any information other than on thier website, and I didn't get any information from my request other than the answer "it tests SO2". I mean, unlike hydrometers, there isn't 100 you tube videos tell me how to use one.

I will probably buy one when I am able to test SO2 levels and verify that it works (or not), but without being able to it's pointless for me. On the other hand if it does work, then it's well worth the money, just no way for me to know at this time.

Ray...

I had inquired about this to Vigo Ltd. and they replied with a link to a site explaining how to read a hydrometer. I don't think it's a scam, but I believe it measures the amount of SO2 in distilled water (in case you make your own custom ratio of solution). I didn't purchase for the same reason. https://www.vigoltd.com/Catalogue/test-equipment/so2-hydrometer

 

[BarrelMonkey]

Thanks @TurkeyHollow, that makes a lot more sense. There is a chart here showing SG values for different strength SO2 solutions. Note that this chart assumes you prepare your SO2 solution by bubbling gas through water; I assume you'd need to account for additional mass if adding SO2 in the form of KMBS/K-meta.

From that chart, a 1% change in SO2 concentration produces a ~0.005 change in SG. That's about the smallest interval that you can measure on a high resolution (+/- 5 brix) hydrometer. 1% (w/v) SO2 is 10,000ppm - so I don't think this instrument will be helpful in measuring the levels in wine...

 

[TurkeyHollow]

Thanks @TurkeyHollow, that makes a lot more sense. There is a chart here showing SG values for different strength SO2 solutions. Note that this chart assumes you prepare your SO2 solution by bubbling gas through water; I assume you'd need to account for additional mass if adding SO2 in the form of KMBS/K-meta.

From that chart, a 1% change in SO2 concentration produces a ~0.005 change in SG. That's about the smallest interval that you can measure on a high resolution (+/- 5 brix) hydrometer. 1% (w/v) SO2 is 10,000ppm - so I don't think this instrument will be helpful in measuring the levels in wine...

I wonder what the difference between bubbling and gas through distilled water and making the solution with KMBS... I always make my solutions up fresh, but I can see where this tool would be handy to see how much SO2 "gassed-off" if stored for an extended period with head space.