should I stop my MLF to prevent low TA, high pH?

[doughowe]

My wine (pinot noir) was started from 10 gallons of Brehm frozen must. Primary fermentation went normally and the wine is now dry. I started MLF 10 days ago and it appears to be proceeding as there are fine bubbles perking in the wine. I've been stirring the lees every 3-4 days. The TA and pH of the wine before MLF were TA=0.68% and pH=3.28.

Yesterday I checked the TA and pH again and found TA=0.59% pH=3.41. I did a chromatography test and found that the malolactic conversion is only maybe 25% done.

Given the 0.1% drop in TA and the rise in pH and the fact that the malolactic conversion appears to have a fair bit more to go, should I be worried about ending at too low of a TA, too high of a pH?

Should I consider stopping my MLF prematurely at some point?

 

[grapeman]

I don't have experience with Pinot from grapes but have to ask why you even started it with numbers like those????

You could let it continue to help the mouthfeel, etc but will likely need to adjust the acid when done.

 

[Paulc]

Hello Doug, I wish I could help you with your question but I am really glad you asked it. I am about to start my first batch of wine from grapes and was assuming I would do MLF(it has been ordered).

I was assuming that a person just did MLF on red grapes but it seems there should be more thought given to it before hand? Is there any rule of thumb for acid/pH level that we can go by? Or is it really mostly about individual taste?

Hope I don't hijack your thread Doug. TIA for your thoughts. paulc

 

[doughowe]

Hi Paul & grapeman
Being that this is only my first try at wine from grapes rather than kits, and my first mlf, I was relying on many resources while planning what I would do. Most seemed to suggest that virtually all reds would benefit from MLF, and most of the recipes seemed to toss in MLB without even considering the starting TA. My must started with a TA of 0.72. It dropped to 0.68 after alcohol fermentation. Further reading suggests TA can typically drop from 0.1-0.3% by an MLF. So I'll probably end up with TA ~0.45-0.5....which will need a tartaric bump up to 0.55% or so. Bummer! Live and learn I suppose. Worst case scenario I could make a syrah and use this as a blender if it's poor on it's own.

 

[ibglowin]

You know Pinots are not all that loaded with acid. They are usually a smooth wine.

I would let it progress to completion. It sounds like you have an excellent grasp on your testing and analysis. Take good notes and let it ride and see how it turns out and learn from it. It may just be awesome.

The other option is two split it into 2 5G batches and add Lysozyme to stop MLF on one and then compare the 2 wines down the road to see which one you like more.

 

[mmadmikes1]

All right, a science experiment. learning is good. Experience is the best teacher in my opionion

 

[pkeeler]

Can you really tell how far the MLF has gone by chromatography? I thought it just told you whether the three acids were present or not. Sounds to me like your pinot numbers are moving into better ranges, I wouldn't stop it.

Can you even stop it with SO2? Wouldn't lysosome be better?

 

[ibglowin]

Yep Lysozyme would be the preferred method. My bad on that one.

Can you see when MLF is complete? Absolutely. Using Chromatography. You place standard acid solutions (Malic, Lactic, Tartaric) on one side and your wine on the other side. You use the pure standards (height) as your reference mark to compare your wine to. Once your wines lactic acid mark reaches the same height as the standard for lactic acid your 100% done.

 

[doughowe]

Thanks for the discussion all. I've seen a lot of pinot noirs from my area with TA in the 0.50-0.55 range...so that's where I'll be hoping to land. I think I'm going to let it ride and see where it goes. If pH is really going too high, I may have to employ the lysozyme...but I'm hoping not to have to do that.

As an aside, malic acid is a dicarboxylic acid, while lactic acid is a monocarboxylic acid. This is why the TA drops when Malic is converted to lactic. I suppose if I actually got a real measurement of the malic acid concentration after alcoholic fermentation I could determine the expected drop in TA as half that value. So if malic acid started at 0.2% I would expect a 0.1% drop in TA as a result of a complete malolactic conversion. Next time it will be interesting to try that. In a while I'll come back and give an update of how far it went and how it turns out...

 

[GHowe]

Great thread

Ahhh, my brother the scientist. Glad you brought all this up, bro. Seems we all want to know the answer! Hope you keep this forum updated with your progress. You've tasted it recently -- do you feel it is too acidic "as is"?

 

[doughowe]

Like so many things with wine making, I'm not sure there is a single right answer to this...just basic guidelines and your taste buds. Last time I tasted it I recorded that it was tart and not tannic. I'm not sure what too acidic or not acidic enough would taste like, being so new to this.

 

[ibglowin]

Bro's on 2 coast!

 

[Rock]

My wine (pinot noir) was started from 10 gallons of Brehm frozen must. Primary fermentation went normally and the wine is now dry. I started MLF 10 days ago and it appears to be proceeding as there are fine bubbles perking in the wine. I've been stirring the lees every 3-4 days. The TA and pH of the wine before MLF were TA=0.68% and pH=3.28.

Yesterday I checked the TA and pH again and found TA=0.59% pH=3.41. I did a chromatography test and found that the malolactic conversion is only maybe 25% done.

Given the 0.1% drop in TA and the rise in pH and the fact that the malolactic conversion appears to have a fair bit more to go, should I be worried about ending at too low of a TA, too high of a pH?

Should I consider stopping my MLF prematurely at some point?

Im sorry if im missing something but whats wrong with your numbers now?

 

[Wade E]

I agree, these numbers are just fine and I dont think they are going to change much. What are you using to check these numbers?

 

[doughowe]

My primary concern was not with the numbers..I like the numbers. My concern is with the rate at which the numbers were changing (0.1% drop in TA in 10 days) and that my chromatography test was showing a lot of malic acid still remains. So my concern was with the fact that I may end up with a TA way too low..pH way too high after converting the remaining malic acid. I've read that 0.1-0.3% is a typical change in TA during MLF. If that's what people see in reality, then I may be OK..may end up too low on the TA. Yet to be seen.

I'm using a Hanna HI98121 pH/ORP/Temp meter to determine pH and TA. It appears to be working correctly and I calibrate it against pH 4 and 7 standards every time I use it. I only got it about 2 months ago, so I have little reason to suspect anything wrong with the pH probe yet.

 

[Wade E]

Yes but you want to rid the wine of malic acid, you can then raise the TA back up with tartaric to get back into range if it truly drops that much. Id let it keep going. Remember next time you want to check malic acid to see if you really need to do MLF. You just may be wasting your time.

 

[GHowe]

thanks

Thanks, guys, for all the input. Yes, my bro and I are on two coasts...kinda stinks...but this winemaking has brought us together to see what we can do. He has the science background, and I am more of a "read up and then try it" type. He is more into reds, me whites. Together we hope to make some good/great wine, and even dream of one day having a true winery together.

We both started with kits, and now he has moved on to frozen grapes, but all we have is what we read and as you guys know it is easy to get downright conflicting info on stuff. We appreciate your experience to help us understand the reality behind all the stuff we read.

So if I hear you right, keep going as is. You don't think it will change the TA and pH all that much from here. And if it does, you believe adding back in Tartaric Acid will bring the TA number back to where it needs to be for his taste.

So now I have to ask, what do you do if your TA and pH are dead on at the end of fermentation, but you want to do MLF? It would be more important to do it for the mouthfeel and add back in tartaric if needed, than to leave it there just because the numbers hit the mark, right?

 

[Wade E]

You really should only do MLF if it needs to be done meaning that malic acid is high. You can adjust mouthfeel by either or both using post fermentation tannins and or glycerin.

 

[doughowe]

Thanks Wade. Next time I'll certainly be measuring malic acid concentration specifically. The book Home Wine Making Step by Step, by Jon Iverson says (pg 51) you can add more acid before fermentation than after without detecting it in the finished product. Further he states you should only up the TA by about 0.15% after fermentation or it "could result in a noticeable post-bottling harshness". Interesting word choice... I suppose I'll make an effort to heed this advice, which means the TA I really don't want to get to is about 0.4%....which would be a drop of 0.28% during MLF. I'll let you all know how it went... Thanks for the tips and advice.

 

[Wade E]

I highly doubt it will even come that close!