Help with crush numbers

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Blazedup

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Hey all,
I just crushed 285 pounds of Petit Verdot from a vineyard here in AZ. The numbers I got using my Vinmetrica sc-300 and refractometer are:
Brix 25
PH 3.87
TA 2.2

I recalibrted the Vinmetrica and double checked the numbers with the same result. A tartaric addition that would raise TA to the 5.5-6 range would be a very large addition. This is my second batch from grapes and I would appreciate some advice on how to proceed from here.
 

Ajmassa

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Similar situation in May with Cab grapes. Good Brix. Good ph. Low TA at around 3.25. (Multiple tests) Added tartaric to try to bring it up to 5-6 range pre fermentation.
TA only went up to 4.5 at first and inadvertently lowered ph way too much.
After fermentation all my levels kinda mellowed to be a bit more balanced and then after MLF a very comfortable 3.5 ph and 8.2 TA.
I honestly think my readings were not true. And some variable I was unaware of was causing false TA levels.

I'm no expert, but I would take that tartaric addition, and cut it in less than half and then roll the dice. And then check levels again after your fermention and MLF if your doing it.
This is advice I was given that held very true. That Tartaric can be a bear. And to always figure out the addition and cut it in half ---for some reason suggested dosages tend to be more than needed. And a little goes a long way. And you can always just add more later if needed
But (not sure how true this is but just deducing from my own experiences) my numbers like to play tricks on me. And I don't fully trust them until the wine is through AF and MLF and stable. So I would just get it to a more "workable" level until then.

Keep us posted on this 2.2 and what you decide. I'm very curious to see if the same thing happens to your numbers after the wine is stable.
 

Boatboy24

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I'd get pH into the 3.6-3.7 range (maybe not even that much), and ignore TA for now. Got to be something wrong with that TA number.
 

salcoco

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I agree, get your ph in line then worry about acid levels based on taste test once wine is completely clear
 

Ajmassa

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If your NaOH is old it usually results in a low TA number.

That would connect some dots. I remember seeing a convo about this in the past. And you also discussed a way to check the NaOH using pH to verify correct? (Just read only 3 month shelf life once opened! Even my "newer" bottle was too old).

I hated my TA testing anyway with the .2 and recently picked up some .1 for this season.
 

ibglowin

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Blazedup

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Thanks for all of the help here. After reading the Vinmetrica instructions again this morning, I realized that I did not multiply my volume of titrant used by 2 per the instructions. Doing the math correctly my numbers are.
Brix 25
PH 3.87
TA 4.4
This would be a much smaller Tartaric addition to get to a reasonable TA and makes more sense with the PH numbers.
My plan going forward is to raise the acid level 2g/L to 6.4 and ferment.
Here's the math I'm using: my 285 lbs of grapes should give me 28.5 gallons of must containing 19.95 gallons of juice (70%).
19.95 gallons = 75.5L. 75.5L X 2g/L=151 grams tartaric.
Does this look correct? I'll wait to hear back before making the addition.
Thanks
 

ibglowin

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Remember to go slooooow. Add 50% of what you think you need. Many times that gets you real close. Not all grapes behave the same.

Thanks for all of the help here. After reading the Vinmetrica instructions again this morning, I realized that I did not multiply my volume of titrant used by 2 per the instructions. Doing the math correctly my numbers are.
Brix 25
PH 3.87
TA 4.4
This would be a much smaller Tartaric addition to get to a reasonable TA and makes more sense with the PH numbers.
My plan going forward is to raise the acid level 2g/L to 6.4 and ferment.
Here's the math I'm using: my 285 lbs of grapes should give me 28.5 gallons of must containing 19.95 gallons of juice (70%).
19.95 gallons = 75.5L. 75.5L X 2g/L=151 grams tartaric.
Does this look correct? I'll wait to hear back before making the addition.
Thanks
 
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