When to adjust pH?

[klemsontigers7]

I have a 50 gallon batch of peach wine going. I haven't checked the pH yet and I'm on about day 5 in the secondary. Do I check it prior to and after backsweetening and then adjust from there? I usually make my peach pretty sweet (not sure of SG, I adjust to taste but will figure out what I prefer this time).

I started my winemaking career last summer with about 3 or 4 five gallon batches of peach and 2 five gallon batches of persimmon. My practices were rudimentary and I backsweetened to taste and had no clue what starting SG and final SG were. This year I plan on making it more of a science.

 

[Stressbaby]

klemsontigers7,

Please feel free to contribute to our thread on persimmon wine variations.

As to when to adjust the pH, many here will tell you to do it preferment. However, you can certainly do it afterwards as well. In any event, I would think you would do it prior to backsweetening, because the amount of sugar you add to balance the wine will depend in part on the acidity.

 

[Turock]

At this point, you should just let the ferment finish and adjust post ferment.

However, this can be dangerous with some fruit wines and some grapes like Mustang because the beginning PH is so low. Very low PH wines can't be adjusted in the post ferment. So it is always best practice to adjust acid pre-ferment.

 

[hector]

Very low PH wines can't be adjusted in the post ferment. So it is always best practice to adjust acid pre-ferment.

That's exactly my Problem .

The pH of my Musts are always very low and I have to add relatively large amounts of Carbonates each time before fermentation and I think that can lead to contamination , because I lost my two previous batches . Although , I had cleaned and sanitized everything very carefully .

How would you deal with such Musts ?

Hector

 

[Turock]

We deal with acidic musts all the time because our soil here is very acidic.

We adjust all our musts before beginning the ferment. Use calcium carbonate to raise the PH to your target. There are no contamination problems associated with carbonate. Very large amounts can lend a chalky flavor, but we have beginning PH's on some fruit of 2.8 or 2.9 and use calcium carbonate to bring the PH to 3.4 with no chalky taste. We do this year after year and I assure you it works fine.

If you have contamination problems, other things are going on--like not enough meta on the fruit, thawing large amounts of fruit without good meta doses---improper nutrient use causing stuck ferments----improper SO2 management post ferment.

 

[GreginND]

Turock,

When you do calcium carbonate adjustments of 0.5 pH units or more, do you treat a portion of the batch and mix it back in, or just add it to the entire batch?

Also, do you have a predictable way to estimate how much CaCO3 you will need to raise the pH properly, or do you just do small additions until you get there?

 

[Turock]

We're not very scientific with this. We add it to the entire batch--stir very well---walk away from it so it integrates--then retest. Because most of the time we're dealing with frozen fruit, it takes 3 days or so to get it to room temp. So the second day of testing, we try to approach the target PH----then on the 3rd day the must is warm enough for the yeast, and before we pitch it we retest the PH and finish it off. The time frame between the second and third day really allows the carbonate to fully integrate so you get a good reading.

Use only 1/4 tsp at a time----it can be easy to overshoot the target PH if you're adding larger amounts.

 

[BeeWine]

The package of calcium carbonate I have calls for 1/2 TSP per gallon before fermentation to lower acidity .01%.

John

 

[Norske]

When using calcium carbonate, is it necessary or required to do a cold treatment?

 

[GreginND]

The calcium tartrates will precipitate over time without cold stabilizing. But it can take a long time for it all to come out - several months. It will drop out in the lees.

 

[hector]

We deal with acidic musts all the time because our soil here is very acidic.
If you have contamination problems, other things are going on--like not enough meta on the fruit, thawing large amounts of fruit without good meta doses---improper nutrient use causing stuck ferments----improper SO2 management post ferment.

Dear Turock ,

Your conditions are very similar to mine and I think that I can learn much from your experience .

Thanks God that I read this thread .

I purchase red grapes every year and after washing with soda ash and water , they are destemed and freezed .

When I'm going to make a batch , I let them thaw and crush them .
Then I adjust the S.G. and the pH ( which was 2.9 after the crush ) and then SO2 is added and I leave it for 12 Hours .

Then Pectinase is added and after 8-12 Hours the pH is once more adjusted because it drops again to 3.0-3.2 and then I re-hydrate the yeast and pitch .

As the Cap forms , I add half of the nutrient ( DAP and 1/8 of a Brewers Yeast tablet which probably is 30-35 mg ) .

What would you say about my Process ?

Hector

 

[hector]

The calcium tartrates will precipitate over time without cold stabilizing.

The salt which precipitates after adding Calcium Carbonate is "Calcium Malate" , not Tartrate .

Hector

 

[Turock]

What kind of grapes are these? There are some grapes you can't really use pectic enzyme on because it makes them slimy. Grapes like concord, Niagara, Catawba need it.

You should get the pectic enzyme on the grapes as you thaw them, along with a proper dose of meta. It makes your PH reading more accurate because the fruit is broken down some and this affects your reading. You'll notice how the PH usually goes up later on as buffers in the grapes are released--potassium and such.

Why are you using brewers yeast???

 

[Turock]

No--Greg was correct. Calcium carb combines with the tartaric to form calcium tartrate. On non-tartaric fruit, it works by dropping out and neutralizing the hydrogen ions.

Bee Wine---It depends on how acidic your must is and what target you're shooting for. 1/2 tsp may be fine to start with, but as you approach your target, you want to cut down on the dose or you can over shoot.

Calcium carb does not need cold stabilization but potassium carb does.

 

[GreginND]

Thanks Turock. Yes, calcium carbonate will react with tartaric acid first before it reacts with malic acid. The double salt (calcium tartrate malate) seems to be a myth. The only way to reduce malic is to take a small portion of the must and treat with calcium carbonate to remove ALL of the tartaric and then some of the malic. Then add that back to the bulk. That means bringing the pH up to 5-6 for that portion. Not something I relish doing to a wine.

 

[hector]

What kind of grapes are these?
You should get the pectic enzyme on the grapes as you thaw them, along with a proper dose of meta.

Why are you using brewers yeast???

I use red table grapes , purchased from a grocery store and it is the only sort available to me for making dark red wine .

As far as I know , the functioning of Pectinase is negatively affected by the presence of an excess amount of SO2 . That's why we add the Enzyme 12 Hours after adding SO2 .

You probably misunderstood what I said about the nutrient . I'm not using any Beer yeast . I use a food supplement Tablet called "Brewers Yeast" which is a natural source of B Group vitamines and contains a range of amino acids , minerals and trace elements .

Hector

 

[hector]

calcium carbonate will react with tartaric acid first before it reacts with malic acid. The double salt (calcium tartrate malate) seems to be a myth.

I've read about "Calcium Malate" in Jack Keller's "The Winemaking Home Page" --> section : ( Advanced Winemaking Basics ) --> acidity in Wines .

Hector