How to test for TA

[gfmonk]

This is the first time making a wine from grapes. The grapes are from my yard and I have a question on how to test for TA. I just got home from crushing/desteming my grapes. Also I have a Vinmetrica SC-300 to do the test with. The question I have is the instructions state to take 100ml of the must and blend it. Does that mean the skins, seeds, stems, etc? Or is it just taking about the liquid juice?

Thanks for the help!!

 

[ibglowin]

I would pick out any (large) stems from the sample but yes they mean get a pretty complete sample of the must with juice and berries. Don't worry about the seeds as they are too small to get pulverized in the blender.

 

[Thig]

This is the first time making a wine from grapes. The grapes are from my yard and I have a question on how to test for TA. I just got home from crushing/desteming my grapes. Also I have a Vinmetrica SC-300 to do the test with. The question I have is the instructions state to take 100ml of the must and blend it. Does that mean the skins, seeds, stems, etc? Or is it just taking about the liquid juice?

Thanks for the help!!

I am thinking of getting the same test meter. Isn't that a rather large sample? Testing 3 or 4 times and that is half a bottle of wine, not very practical if you are just making a 1 gallon recipe. I know most people make more than one gallon batches but if you just wanted to try out a fruit wine to see if you like it that would be a lot to use just for testing.

 

[ibglowin]

The sample size is 5ml. Just toss the rest back into the primary and let it ferment.

 

[gfmonk]

I decided I would test ph until I had the right procedure for the ta. The ph for one batch is 4.04 and for the zin grapes it is 3.92. Is the ph too high? If so what do I use to lower it?

 

[ibglowin]

First what type of grapes are these?

Tartaric acid is what you need to lower the pH but this will also effect the TA so you need to test for both and get a number for both before you do any adjustments at all.

 

[gfmonk]

Thanks Mike. One batch is zin grapes, the other batch are grapes from Cornell which are hybrids. How exact does the measurement for the must need to be? The problem I'm having is that the pipette doesn't have a large enough opening to allow for the must to be drawn up into it. Something like a grape skin or seed keeps blocking the opening.

 

[ibglowin]

Let the solids settle out or filter the sample through a coffee filter. You need to get as accurate amount of sample as possible into the syringe. (no air bubbles etc)

What are your Cornell hybrids?

 

[gfmonk]

It's too thick to go through a coffee filter. I waited 30 minutes for the last sample to clear and it never really did. I'm wondering if I'm doing something wrong.

 

[gfmonk]

I found another filter (actually it was to remove the egg yolk from an egg) I could use and it worked. The Zin is ph 3.92, ta 6. The Cornell is ph 4.04 and ta 7.6.

 

[grapeman]

If you just take about 100 grapes picked off the stems and put them in a ziplock bag, you seal the bag up keeping excess air out. Then just squash them up good and you get a well mixed juice without a seedy mess. Unzip a corner of the bag and carefully pour out just the juice. You can easily get enough juice for a full sample test of brix, pH and TA. If you wish, you can put the rest of the contents of the bag and extra juice back into the must. Just be sure you throw out any part of the sample you added chemicals to.

 

[gfmonk]

I have high ph in both batches but the ta seems to be inline with what I would want. Do I add tartaric acid and if so how much per gal?

 

[Runningwolf]

If you just take about 100 grapes picked off the stems and put them in a ziplock bag, you seal the bag up keeping excess air out. Then just squash them up good and you get a well mixed juice without a seedy mess. Unzip a corner of the bag and carefully pour out just the juice. You can easily get enough juice for a full sample test of brix, pH and TA. If you wish, you can put the rest of the contents of the bag and extra juice back into the must. Just be sure you throw out any part of the sample you added chemicals to.

I also test exactly as Rich stated. Ensure when you're picking your grapes, pick them from about 4 different locations. On top of the canopy, under the canopy and the beginning, mid way and end of the row. Also when picking from the ends I start at least 2 posts in, especially if it's near a road.

 

[gfmonk]

Thanks for the tip!! I'll have to remember that next year.

 

[ibglowin]

Try running the pH and TA again using Grapeman's method and report back the numbers.

 

[gfmonk]

I don't have any uncrushed grapes.

 

[ibglowin]

Just take a sample and do as suggested. Get some juice in the bag as well and SQUEEZE it out!

 

[Rock]

gfmonk there are some good books on wine making that you should invest in as well.It will help you along and you can use them as reference.

 

[gfmonk]

Thanks for the help everyone. Rocky I have a couple of books that I have purchased but unforchantly they don't always give you the details. In this case if you go back to my original question, the answer seems to be you test just the juice and not everything, but if that's true then why would you have to blend it? I will call Vinmerica and see what they say.

For the question about how much TA to add to the must, what I have read talks about TA crystals and I have a powder. Again the devil is in the details.

 

[gfmonk]

I just talked to Vinmetrica and what they said was what Mike was suggesting. Take a representive sample of the must, skins, seeds and all. Blend it and filter it through a course filter, like cheesecloth and use that as your sample.