Reducing Acid mid fermentation.

[Applewineguy]

My acid test kit arrived today and figured it would be good to test my batch. I removed all the CO2 from the sample taken and then performed my acid test. I came to 0.8% or 8g/L and I'm aiming for a 0.6%. I'm mid way through fermentation in my raspberry apple honey wine and would like to adjust while it's in this stage if possible. What would be the best way that won't negatively impact my wine? Any insight would be greatly appreciated.

Starting S.G was 1.113 and it is currently at 1.070 and going down 0.010 every 12 hours.

 

[Rice_Guy]

In the fermentation the pH is critical. Is your pH under 3.5?

If you have to lower it, ,,, an apple product has malic acid and many ciders undergo MLF. ,, Chemically one can add calcium carbonate or potassium bicarbonate. For a major shift potassium can make bitter flavors, however it is faster/ reacts basically instantly. I would try a small bench trial before dosing the whole batch.

It is interesting that you identified the flavor as too acidic while there still is sugar in the system. Folks drink wine/ flavor, not a set of numbers.

 

[Applewineguy]

In the fermentation the pH is critical. Is your pH under 3.5?

If you have to lower it, ,,, an apple product has malic acid and many ciders undergo MLF. ,, Chemically one can add calcium carbonate or potassium bicarbonate. For a major shift potassium can make bitter flavors, however it is faster/ reacts basically instantly. I would try a small bench trial before dosing the whole batch.

It is interesting that you identified the flavor as too acidic while there still is sugar in the system. Folks drink wine/ flavor, not a set of numbers.

I'm still waiting for my PH tester. Should be here next week.

I didn't detect the acid by taste. I normally always test before fermentation but just got back into making wine again and didn't have a test kit yet before making this batch.

I'm not sure how significant 0.8% is as I've never dealt with a high acid and always had to add acid in the past to previous wines to reach my target 0.6% that is that standard for fruit wines.

It's not just about taste, also about storage which acid can play a factor in for longevity. I of course don't chase just numbers and value taste and mouth feel but like to have certain things within proper parameters.

I appreciate your comment thank you

 

[winemaker81]

Messing with acid in mid-ferment may stunt the yeast as you may be radically changing their environment. Generally speaking, adjust acid before or after ferment, not in the middle.

Check pH before inoculation. If the pH is between 2.9 and 3.9, the must will ferment fine, although some yeast may not like the lowest numbers.

I adjust acid by taste, after aging. pH and TA can vary a lot, depending on the other constituents in the wine, so a particular number (for either) has no real value.

 

[Rice_Guy]

not sure how significant 0.8% is as I've never dealt with a high acid and always had to add acid in the past to previous wines to reach my target 0.6% that is that standard for fruit wines. . . also about storage which acid can play a factor in for longevity

There is quite a bit of variation in what level of TA will win a first place in a contest, , , 0.6% is not a magic number.

A guideline for where to balance TA on wine;
after club contest this year I collected eight first place wines which are the red triangles
View attachment 81200
The sample set "cloud" is primarily commercial wines, with some collected in the vinters club and here on WineMakingTalk
NOTE: TA is one of several quality traits which a first place wine has as absence of flavor defect, appropriate aroma for the variety and clarity , , , etc.
NOTE 2: this is an easy test, if ya'll are interested in your wine ,,, PM me

The first judgement is how does it look. Next is how does it smell. Then we we finally get to taste and estimate the pH or TA. Many old recipes would dilute the smell / total solids / cost of product with water.
As an industry person, the patents tell me for safety and shelf life low pH is better until the yeast stop ,,, below pH 2.8. Sometimes the better wine/ beverage also Carrie’s a TA of 1%

 

[Hazelemere]

71b yeast

 

[BarrelMonkey]

I second @winemaker81 's recommendation to let things ferment out before testing and potentially adjusting.

I removed all the CO2 from the sample taken and then performed my acid test.

The devil is in the details... How did you remove CO2 and what acid test did you use?

For removing CO2 I just shake my sample tube vigorously and 'burp' it several times until there is no more hiss of gas when I open it. More rigorously, I have sometimes put it under vacuum for 5 minutes. But I've never tested samples that were still fermenting... in this case I think you'd have to centrifuge out the yeast and degas the decanted supernatant.

 

[Applewineguy]

I second @winemaker81 's recommendation to let things ferment out before testing and potentially adjusting.


The devil is in the details... How did you remove CO2 and what acid test did you use?

For removing CO2 I just shake my sample tube vigorously and 'burp' it several times until there is no more hiss of gas when I open it. More rigorously, I have sometimes put it under vacuum for 5 minutes. But I've never tested samples that were still fermenting... in this case I think you'd have to centrifuge out the yeast and degas the decanted supernatant.

Sample tube and shook the snot out of it until essentially no bubbles appeared after shaking. Took some time haha.

I did find my PH is at 2.86 and the acid is at 0.8% (8g/l)

My wine is now at 1.040 and it's dramatically slowing down in her fermentation process. I added some yeast energizer today and gave a good stir and then there was a lot of foam but once died down quickly and then I actually thought it stalled entirely. I ran to go get my ph tester from the mail and then calibrated it and its now bubbling again in primary but I do worry it will stop before it's done.

 

[Applewineguy]

Messing with acid in mid-ferment may stunt the yeast as you may be radically changing their environment. Generally speaking, adjust acid before or after ferment, not in the middle.

Check pH before inoculation. If the pH is between 2.9 and 3.9, the must will ferment fine, although some yeast may not like the lowest numbers.

I adjust acid by taste, after aging. pH and TA can vary a lot, depending on the other constituents in the wine, so a particular number (for either) has no real value.

I did find my pH is at 2.86 which is not ideal for yeast by any means. (Meter just arrived today, using Apera PH60 pH tester) calibrated with all 3 solutions step by step.

 

[Applewineguy]

71b yeast

I'd have to order some. Is there a reason that one is better? The 1116 I used originally is supposed to be a rather hardy yeast and tolerant of poor conditions which I've learned isn't the case lol. It's actually seeming to be very picky.

 

[Hazelemere]

I'd have to order some. Is there a reason that one is better? The 1116 I used originally is supposed to be a rather hardy yeast and tolerant of poor conditions which I've learned isn't the case lol. It's actually seeming to be very picky.

71B eats malic acid 1116 doesn't

 

[Applewineguy]

71B eats malic acid 1116 doesn't

So 71B would be better in high acid fruit musts?

 

[winemaker81]

I did find my pH is at 2.86 which is not ideal for yeast by any means. (Meter just arrived today, using Apera PH60 pH tester) calibrated with all 3 solutions step by step.

Yup, that's low. If you adjust now, go gentle on the adjustment, with the goal of completing fermentation. If it's still too acidic post fermentation, you can adjust that later.

I learned the hard way to not make significant adjustments during fermentation.

 

[Applewineguy]

Yup, that's low. If you adjust now, go gentle on the adjustment, with the goal of completing fermentation. If it's still too acidic post fermentation, you can adjust that later.

I learned the hard way to not make significant adjustments during fermentation.

I'm not even sure how to adjust. I've never had too adjust this far.

 

[winemaker81]

So 71B would be better in high acid fruit musts?

Lowering pH / raising TA is easy -- add acid. For grapes use tartaric, for apples use malic. For other fruits, lookup what the dominant acid is and use that.

To raise pH / lower TA pre-fermentation? That's more problematic. Potassium bicarbonate, potassium carbonate, and calcium carbonate will reduce acid, but have the potential to introduce a metallic taste. I've had bad luck with this approach and hesitate to use it. I'd calculate how much is necessary and add 1/4 that amount, as it's far easier to add more than to take some out. Also note that calcium carbonate can take up to a month to fully work, so it's not a good one for pre-fermentation.

A better choice is to blend with a low acid juice. That will alter flavor, but with a pH of 3.86, you won't need a lot to push the pH into a range the yeast will prefer.

Do this in conjunction with a yeast that eats acid, such as 71B and Renaissance Avante.

Post-fermentation? My preferred approach is cold stabilization, as it has the least negative side effects. This can work for grapes or any fruit with significant amounts of tartaric.

Blending with a lower acid wine is my second choice.

Depending on the wine, backsweetening does not reduce the acid, but it reduces the perception of acid.

x-carbonate is my last choice, for the above stated reasons.