Natural High TA levels?

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Sep 8, 2009
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How's it going?

I went to my local brew supply store last week and bought an Acid testing kit. Came with 0.1N of NaOH and the phenolphthalein color indicator. I honestly can say... I'm having so much fun with it! (I'm serious, wine making is a lot of fun.)

I have a nice golden plum wine on the go, it just finished fermentation and is now racked, sulfite and sitting in two carboys for bulk aging. During my racking process, I did the Acid test and it measured 0.94% TA. That's high for any kind of wine:
Dry White Grape Wines..........0.65-0.75%
Sweet White Grape Wines.......0.70-0.85%
Dry Red Grape Wines.............0.60-0.70%
Sweet Red Grape Wines..........0.65-0.80%
Sherry Grape Wines.................0.50-0.60%
Non-Grape White Wines..........0.55-0.65%
Non-Grape Red Wines.............0.50-0.60%
Source: Jack Keller's website, sorry the forum wouldn't let me post the link with this thread as I'm a "newbie." (I understand, forum is trying to prevent ignorant people who register simply to spam)

I did the same test on an apple wine that I am fermenting. The TA came out to be to be about 0.84%. Finally I tested my white grape wine. This is a white grape that we got permission and happly picked from my friend's landlord fence. It's a fantastic jelly testing white grape. However, I'm not sure what kind it is. Anyways, it's in 1st fermentation and it was at 1.2%. I was wondering why are all my wines so high? All my musts are from fruits that were grown locally here in Vancouver, BC.

I became very curious if my NaOH solution was faulty, possibly an old batch and perhaps it lost strength? So following the procedures outlined from BCAWA website (again sorry I can't post the link, for reference please google BCAWA Acid Control in Winemaking and see "Shelf-life of Sodium Hydroxide Solution".) Anyways, the procedure is to make a sample that you know contains 0.5% TA and then see if your NaOH will measure it correctly. I percisely weight 1 gram of tartaric acid and placed it in 200mL of distilled water to get the 0.5% known sample and I tested it with the NaOH testing solution. (How ironic, I'm testing my testing solution.) I performed the acid TA test and measured my known 0.5% solution at 0.48% the first time and again 0.48% the second time. Now I am convinced that my NaOH solution is fine and my tests are within an acceptable accuracy range.

Thus, now I'm stuck wondering why are my musts so high? So I'm wondering, have you guys encountered such natural high TA levels in your must? AsI mentioned, the fruits in my wines are all grown locally here in Vancouver, BC and I did not add anything to them, except yeast, and pectic enzyme during pressing. Could that be it? The pectic enzyme in contact with the skins of the fruit too long?

Finally I did taste all my musts. They taste too young and yeasty for me to really tell.

Thanks for the help,
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Well actually I am not surprised on the plum wine.
I made plum wine myself this year and the acidity tested at 10.

Look here for the story:

My wild grapes even tested at 11:

The apple wine worries me a bit but that depends on the kind of apples you used.

There is an easy way to test your testing kit.

Take 1 liter of water.
Now add 7 gram tartaric acid. Dissolve it well !!!
And that is strict: no citric or malic !!!
Now the test should give 7 !!!

Off course you could use 6 gram or 8 gram or whatever. But the measurement should indicate what you added.

If you want to see how I did this test myself read this story:

If the measurement is off there is SOMETHING wrong.

Ah yes... I remember reading your plum wine story a while ago and saying to my Girlfriend, "HOLLY COW 30kg of plums! I want to go hang out with Luc in the Netherlands because I like his style."

Anyways, thanks for letting me know about the TA. So I'm not off track. As for the apples, yeah they were high, but that's the value they are.

I did the samething as you, I dissolved a known quantity of tartaric acid in distilled water to test my NaOH solution . But I used 200mL of solvent and 1gram of solute to yield the 0.5%. (I just wanted a small 0.5% batch because what would I do with 1L qty of dissolved Tartaric Acid?)

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