Acid adjustment thoughts.

[Vern]

Just finished fermentation on cold hardy grapes. Marquette, petite pearl and verona. Prior to fermentation brix 23, ph 3.6 ta 8.5. Used 71b yeast and added mlf 2 days later. After fermentation sg .996 ph 4.05 and ta 5.25. I used new solutions for testing. In past years post fermentation numbers were around ta 7.5 and ph around 3.6. Had a very hot summer in Southern Wisconsin. What would be your recommendation? Thanks .

 

[cmason1957]

My recommnedation would be to leave it alone a bit, like a month or two. Let MLF finish, for certain, verify that your Ph meter is accurate and check again. How does it taste for such a young wine? I would expect it to be a bit sharp with the CO2 dissolved in it.

 

[Vern]

My recommnedation would be to leave it alone a bit, like a month or two. Let MLF finish, for certain, verify that your Ph meter is accurate and check again. How does it taste for such a young wine? I would expect it to be a bit sharp with the CO2 dissolved in it.

Checked meter , seems ok. Wine actually taste good which isn't normal.

 

[Boatboy24]

CO2 could be throwing your readings off - shake up your sample to be sure all the gas is out.

 

[Rice_Guy]

a pH of 4.05 is a short shelf life wine, if CO2 is creating an error as Jim offered it will be decreasing the pH by one or two tenths therefore when fully degassed it could be as high as 4.25.

This leads to the choices, do you want to run higher on metabisulphite? Or blend a lower pH wine? or add acid? With the tools I have in house I would bench trial 85% phosphoric and try to push the pH faster than the TA, citric is also a trivalent acid but can be metabolized by malic culture giving a buttery flavor so use it in combination with high SO2 , ,,, finally as a short shelf life you could plan to use it in a year,

 

[Tim3]

How much wine did you produce? During MLF you might expect PH to rise upwards of another .15 as well. So if you do nothing you’ll end up near 4.2 which is, by any definition, a flabby wine. Since you’ve already added your bacteria I agree with cmason and you should let it finish. But then you might consider a tartaric acid addition. If you tell us your wine volume I can help with the size of your addition.

 

[Vern]

How much wine did you produce? During MLF you might expect PH to rise upwards of another .15 as well. So if you do nothing you’ll end up near 4.2 which is, by any definition, a flabby wine. Since you’ve already added your bacteria I agree with cmason and you should let it finish. But then you might consider a tartaric acid addition. If you tell us your wine volume I can help with the size of your addition.

55 gallons. Thanks to everyone for your help

 

[Tim3]

I’m surprised there was such a jump in PH during primary fermentation. Usually you might see an increase of around .15, with another increase of .12 occurring during MLF. So that jump of .45 just in primary is very surprising. But either way, the most you’ll want to adjust your must with acid additions is by .42 PH. More than that and it’ll taste unbalanced. So let’s assume your PH continues to increase another .12 during secondary to 4.17. You can get it back down to 3.75 by adding 403 grams of tartaric acid. That’s still a very approachable wine, but will require a slightly larger addition of sulfite post MLF. Test PH again after MLF and before acid addition though, as I’m doubtful the PH really rose that much from before primary. If your wine followed a typical PH increase from where you started you’d only want to add 348 grams tartaric acid and you’d likely end up with a very nice PH of 3.6

 

[Vern]

I’m surprised there was such a jump in PH during primary fermentation. Usually you might see an increase of around .15, with another increase of .12 occurring during MLF. So that jump of .45 just in primary is very surprising. But either way, the most you’ll want to adjust your must with acid additions is by .42 PH. More than that and it’ll taste unbalanced. So let’s assume your PH continues to increase another .12 during secondary to 4.17. You can get it back down to 3.75 by adding 403 grams of tartaric acid. That’s still a very approachable wine, but will require a slightly larger addition of sulfite post MLF. Test PH again after MLF and before acid addition though, as I’m doubtful the PH really rose that much from before primary. If your wine followed a typical PH increase from where you started you’d only want to add 348 grams tartaric acid and you’d likely end up with a very nice PH of 3.6

Thanks, I will wait until mlf is complete, retest and post results. I agree this jump is odd. In the past 5 years nothing like this has occurred.

 

[Vern]

I’m surprised there was such a jump in PH during primary fermentation. Usually you might see an increase of around .15, with another increase of .12 occurring during MLF. So that jump of .45 just in primary is very surprising. But either way, the most you’ll want to adjust your must with acid additions is by .42 PH. More than that and it’ll taste unbalanced. So let’s assume your PH continues to increase another .12 during secondary to 4.17. You can get it back down to 3.75 by adding 403 grams of tartaric acid. That’s still a very approachable wine, but will require a slightly larger addition of sulfite post MLF. Test PH again after MLF and before acid addition though, as I’m doubtful the PH really rose that much from before primary. If your wine followed a typical PH increase from where you started you’d only want to add 348 grams tartaric acid and you’d likely end up with a very nice PH of 3.6

Another comment, this year I used 71b and past years pasture red. Also I took off 8 gallons of juice after crushing.

 

[Raptor99]

a pH of 4.05 is a short shelf life wine, if CO2 is creating an error as Jim offered it will be decreasing the pH by one or two tenths therefore when fully degassed it could be as high as 4.25.

Since CO2 can lower the pH but not raise it, if my pH measures too high I feel confident adding some acid blend without degassing. I might need to add a little more after degassing, but at least it would be in the right ballpark.

 

[winemaker81]

Since CO2 can lower the pH but not raise it, if my pH measures too high I feel confident adding some acid blend without degassing. I might need to add a little more after degassing, but at least it would be in the right ballpark.

That sounds reasonable. However, go gentle on the addition -- I'd add only 1/4 to 1/2 of what you calculate you need. It's very possible to over-do it and get into a "fix-the-acid" yo-yo. Make the addition, stir well, and let rest a few days, even a week. Taste test and add more as needed. Trust your tastebuds on this, as the pH meter will not be drinking the wine, you will.

 

[Raptor99]

Yes, I add acid a little bit at a time. When I first started making wine I overshot the target a few times. Been there, done that.

I don't have a good way to calculate how much to add. But based on past experience I have a feel for how much acid is needed. I add less than I think will be needed and then wait. As you say, I have discovered that waiting a few days helps the acid to be fully integrated into the wine. Multiple adjustments on the same day doesn't work very well.

I check and adjust the pH if necessary at the end of primary. Sometimes it is difficult to get an accurate reading with the fruit bag still in the bucket. If the pH is too high, I risk unwanted microorganisms growing in secondary. So at that stage the pH is about preservation. At the end of bulk aging, any acid adjustments are primarily about the taste.

 

[Tim3]

Since CO2 can lower the pH but not raise it, if my pH measures too high I feel confident adding some acid blend without degassing. I might need to add a little more after degassing, but at least it would be in the right ballpark.

If you’re making wine from grapes I would suggest not using an acid blend and instead only using tartaric acid for the addition.

 

[Raptor99]

If you’re making wine from grapes I would suggest not using an acid blend and instead only using tartaric acid for the addition.

I make fruit wine, so acid blend usually works pretty well. For hard cider I plan to use malic acid. For blueberry wine I use at least part citric acid.

 

[AaronSC]

I’m surprised there was such a jump in PH during primary fermentation. Usually you might see an increase of around .15, with another increase of .12 occurring during MLF. So that jump of .45 just in primary is very surprising. But either way, the most you’ll want to adjust your must with acid additions is by .42 PH. More than that and it’ll taste unbalanced. So let’s assume your PH continues to increase another .12 during secondary to 4.17. You can get it back down to 3.75 by adding 403 grams of tartaric acid. That’s still a very approachable wine, but will require a slightly larger addition of sulfite post MLF. Test PH again after MLF and before acid addition though, as I’m doubtful the PH really rose that much from before primary. If your wine followed a typical PH increase from where you started you’d only want to add 348 grams tartaric acid and you’d likely end up with a very nice PH of 3.6

I have seen this "pH rise" happen myself, not infrequently. Often, it is not caused by fermentation per se, but by the grapes themselves after crush. If you crush your reds and check the brix/pH right after crush you will get a lower brix and lower pH than you will if you let them sit over night and test then. Often this is pretty dramatic. Some grapes are more susceptible to it than others. For example, Grenache and Mourvedre don't really seem to jump too much. Syrah and Touriga REALLY jump in brix and pH over night and during ferment. Zinfandel is famous for doing this -they call it "brix creep"...

I generally add tartaric acid to get this up to 6 or 6.5 g/l, even before fermentation, for reds. ML will reduce the acid for sure, as will aging and cold stabilization. A pH above 4 is going to give you a wine that will be open to all sorts of misadventures, as other have pointed out.

 

[Vern]

I have seen this "pH rise" happen myself, not infrequently. Often, it is not caused by fermentation per se, but by the grapes themselves after crush. If you crush your reds and check the brix/pH right after crush you will get a lower brix and lower pH than you will if you let them sit over night and test then. Often this is pretty dramatic. Some grapes are more susceptible to it than others. For example, Grenache and Mourvedre don't really seem to jump too much. Syrah and Touriga REALLY jump in brix and pH over night and during ferment. Zinfandel is famous for doing this -they call it "brix creep"...

I generally add tartaric acid to get this up to 6 or 6.5 g/l, even before fermentation, for reds. ML will reduce the acid for sure, as will aging and cold stabilization. A pH above 4 is going to give you a wine that will be open to all sorts of misadventures, as other have pointed out.

Thanks to everyone for your advice. I will confirm mlf completion in 3 weeks. After which I will add tartaric acid in small amounts. Then retest and add small amounts if needed. I will taste each time. This is first time I had such a large jump in ph. I did let fruit hang an additional 10 days longer this time.

 

[Tim3]

I have seen this "pH rise" happen myself, not infrequently. Often, it is not caused by fermentation per se, but by the grapes themselves after crush. If you crush your reds and check the brix/pH right after crush you will get a lower brix and lower pH than you will if you let them sit over night and test then. Often this is pretty dramatic. Some grapes are more susceptible to it than others. For example, Grenache and Mourvedre don't really seem to jump too much. Syrah and Touriga REALLY jump in brix and pH over night and during ferment. Zinfandel is famous for doing this -they call it "brix creep"...

I generally add tartaric acid to get this up to 6 or 6.5 g/l, even before fermentation, for reds. ML will reduce the acid for sure, as will aging and cold stabilization. A pH above 4 is going to give you a wine that will be open to all sorts of misadventures, as other have pointed out.

Great points you make. For my red wines I’ll always wait 2 days following crush, and will measure and adjust at that time during cold soak and after a few good mixings.

 

[Vern]

I’m surprised there was such a jump in PH during primary fermentation. Usually you might see an increase of around .15, with another increase of .12 occurring during MLF. So that jump of .45 just in primary is very surprising. But either way, the most you’ll want to adjust your must with acid additions is by .42 PH. More than that and it’ll taste unbalanced. So let’s assume your PH continues to increase another .12 during secondary to 4.17. You can get it back down to 3.75 by adding 403 grams of tartaric acid. That’s still a very approachable wine, but will require a slightly larger addition of sulfite post MLF. Test PH again after MLF and before acid addition though, as I’m doubtful the PH really rose that much from before primary. If your wine followed a typical PH increase from where you started you’d only want to add 348 grams tartaric acid and you’d likely end up with a very nice PH of 3.6

An update, confirmed mlf completion, bought new chemicals, put new batteries in sc300, ran test on 3 separate carboys, Results are ph 4.05 TA 5.4. Wine tastes really good. Thinking of adding 1/2 gram tartaric acid per liter and retest in 30 days. Also I pulled off some juice from crushed grapes and froze. Started fermentation today. PH 3.42 and TA was 6.6 brix is 22. These are the same grapes as above. Does this correction seem ok?

 

[Raptor99]

That makes it flexible because you can make any blend that you want. I don't want the same blend for everything.