adjusting TA prior to MLF

[spinelli01]

I would like to get your opinion on adjusting TA prior to MLF. I bought 7 gallons of frozen must (sangiovese), which had a low TA (5.4). I adjusted the TA prior to primary fermentation. Fermentation is now complete, and I will be pressing tonight. My numbers from testing last night are as follows

pH 3.51
TA 4.6

I plan on going through an MLF, which I know will lower the TA. Should I adjust TA prior to MLF? I feel that I should so the pH doesn't get too high and I end up with a problem. I also plan on testing after press to see if any of my numbers adjust during the pressing process. What are your thoughts?

Thanks!!

 

[ShawnDTurner]

that seems low for a wine that is known for it High acidity. I would adjust before malo.

 

[spinelli01]

would you have any concerns about over correcting the pH and it ends up being too low for MLF? Is there enough of a buffer in wine that it would be very difficult to over correct the pH?

 

[ShawnDTurner]

I would not over correct before MLF. I would make a near adjustment, so small increment. Wineries often make adjustment knowning that they will be going through MLF so they will not have to make huge adjustments once complete.

 

[spinelli01]

That makes sense. You hate to risk spoilage from a high pH. I will go ahead and make an adjustment. I think I may adjust for pH instead of TA and see how it goes. You add less tartaric acid for pH adjustments. Would you agree?

 

[blazerpb]

Just my opinion but 3.5 PH is pretty good for Sangiovese. If you adjusted the TA prior to fermentation then I would wait until MLF completion and test again. Also give the wine a taste you may want to leave it alone if it tastes good.

 

[robie]

Yes, the PH will rise during MLF. You can go either way, though.

The acid for a Sangiovese should be a little higher, if you intend to pair it with food. Italian wines are made for pairing, so they tend to have a little higher acid.

You can adjust before MLF, but you have to be careful. If you get the
PH too low, you will end up having to use a special, low PH MLB, which you likely will have to special order.

When adjusting TA (anytime!!!), always calculate how much acid to add, then add ONLY HALF that amount. The formulas are just not that reliable, considering that each batch of wine is so very different from any other. This way you can adjust, then test and possibly adjust again.

In your case, you should not even attempt that second test/adjustment. Lower the PH just a little, then start the MLF.

After MLF and stabilizing, adjust the acid again by taste, as long as the PH ends up in a good range for protection.

 

[ibglowin]

My $0.02 but I would let it ride and see what you have post MLF. If your not careful you gonna over shoot and end up with a pH of 3.3 or something then risk a too low pH for successful MLF.

 

[spinelli01]

I took everyone's advice

. After pressing, my pH increased to 3.6 and my TA decreased to 3.9, so I decided to add 1/3 of the amount of Tartaric acid calculated. It raised the TA to 4.35 and decreased the pH to 3.48. At this point, I am not touching it and will begin MLF tomorrow. I tasted it after the addition, and the taste was much better. A little more depth to it - actually pretty good! Can't wait to take it through MLF. This was a frozen bucket of must from M&M. Pretty happy with it. Thanks for the advice!!!

 

[blazerpb]

Please correct me if I am wrong but the best time to check PH is at crushing (Or in your case with frozen juice just prior to pitching yeast) and after MLF. CO2 gas from the fermentation will throw off the pH reading. Even though you have pressed there still may be CO2 gas which can throw off your readings.

 

[ibglowin]

Pressing will pretty much blow off all the CO2 guaranteed. Ideally yes, you want to make your additions upfront and prior to fermentation. Sometimes the best laid plans of mice and men do not work out so you make the additions later on and as best you can. Not optimal but with time the wine will come together either way.

 

[robie]

Pressing will pretty much blow off all the CO2 guaranteed. Ideally yes, you want to make your additions upfront and prior to fermentation. Sometimes the best laid plans of mice and men do not work out so you make the additions later on and as best you can. Not optimal but with time the wine will come together either way.

I agree with Mike. Not much CO2 can be left after pressing.

Upfront adjustments are much better and can help insure the best possible good happens during fermentation. Balance! Adjustments after the wine is stabilized is more about taste and protection. I say "protection" because if the PH is too high, it can shorten the life of the wine and require larger doses of SO2 to get the necessary protection. Other than the protection issue, it should be all about the taste.

 

[joea132]

It also depends when you crush. If you crush at a higher brix level you may have significant CO2. Just being devil's advocate.

 

[spinelli01]

The Brix was zero at press when I took the sample. The reason I took the sample was to make sure the environment was ideal for MLF.

I know there are a few time points when it is recommended to start MLF (simultaneously with yeast: at a Brix of 5; and after primary fermentation is complete). I chose to start MLF after primary fermentation because I read some discussions on the bacteria metabolizing sugar instead of malic acid, which can cause problems in the wine. My plan is to pitch MLBs with optimalo.

Any thoughts on this issue from the more experienced wine makers out there?

 

[ibglowin]

Keep it warm but not too warm. 65-70 is really the sweet spot for MLB. Watch for the tiny bubble ring at the top to form.

 

[robie]

It also depends when you crush. If you crush at a higher brix level you may have significant CO2. Just being devil's advocate.

I assume you mean press, instead of crush.
Yes, some wine makers press at different points in the process, based on factors such as the amount of tannins. If one pesses before fermentation is completed, certainly there will be a new buildup of CO2.

 

[robie]

I know there are a few time points when it is recommended to start MLF (simultaneously with yeast: at a Brix of 5; and after primary fermentation is complete). I chose to start MLF after primary fermentation because I read some discussions on the bacteria metabolizing sugar instead of malic acid, which can cause problems in the wine. My plan is to pitch MLBs with optimalo.

Any thoughts on this issue from the more experienced wine makers out there?

I think the MLB will only eat other food besides the malic acid in significant quantity, if they run out of malic acid. This is a good reason to test for when MLF is completed so one can immediately kill the MLB with a good dose of SO2. MLB eating other things besides malo can create off flavors.

There are several circumstances that can affect when a wine maker will start MLF. I'll give just a couple.

Because one usually can't add SO2 after alcohol fermentation and before MLF is completed, it can result in the wine being unprotected for long periods of time, as some MLF's can take 6 t 8 weeks to complete. If the quality of the grapes are a little suspect to start with, even though an initial, dose of Kmeta should have been added before alcohol fermentation, the wine is more susceptible to spoilage because of the long MLF. In this case the wine maker may choose to start the MLF while alcohol fermentation is still going.

MLF creates a buttery flavor in the wine because MLF produces a chemical - diacetyl. This buttery flavor generally is more favorable in whites than in reds. Some consider it a flaw in reds. Alcohol fermentation tends to remove the diacetly, so for reds, if MLF is started before alcohol fermentation is completed, the wine should end up with less diacetyl.

Using similar logic for whites, starting MLF after all alcohol fermentation is completed should result is more diacetyl in the finished white wine.

Special added nutrients just for the MLB is less necessary if alcohol fermentation is still underway.

 

[spinelli01]

Interesting about the diacetyl in reds. I thought the majority of reds were put through MLF and only a few whites.

You gave me an idea though. I can order the exact same frozen must, and start MLF at a Brix of 5 for the second wine. Then compare the two finished wines.

What is nice about ordering frozen must is it lessons the risk of native yeast or bacteria begining fermentation. The supplier recommends not adding SO2 at all if MLF is going to be initiated. I added about 10 ppm anyway to be safe. To be perfectly honest, this is only my 3 batch of wine but I do read and research it as much as possible (without being fired from my real job)! It is slightly addicting!

 

[GreginND]

Think of a big buttery chardonnay. That butter comes from MLF.

 

[ShawnDTurner]

it depends on how much Malic is in the Wine, just because you go through MALO it does not ensure there is enough to produce diacetyl in levels that will be detected by our senses.