How do you measure your must?

[zadvocate]

My TA measurements seem to be higher than my original measurement prefermentation. all three have gone through MLF.


wine Beginning PH Begging TA 6 mths out(PH) 6 mths out(TA)
Zin 3.79 5.25 3.69 6.75
Pino No. 3.45 6 3.4 6.3
Tuscan 3.51 6 3.53 6.5

I just bought a new test kit and followed the instructions except I measured with a PH meter to 8.2.
As for the TA kit, it says to add 15 ccs of wine, dilute to rose, add 3 drops of indicator, then add Naoh til the color changes...... I used the PH meter to measure when it hits 8.2 instead. The kit didn't give instructions for using the PH meter, that isn't a problem is it?

I am assuming I am doing something wrong measuring my must. So how do you prepare or measure your must prior to fermentation?

Thanks for the help

 

[cmason1957]

Since you say you used your phone meter this time to measure your TA endpoint, I am guessing that means you didn't use it for your preferment numbers. I never could tell when I was done with red wines and color changes. I would assume those numbers aren't correct. As a side note fermentation does cause the pH and tasty both to change, usually pH goes up. TA can go either way.

 

[Johnd]

My TA measurements seem to be higher than my original measurement prefermentation. all three have gone through MLF.


wine Beginning PH Begging TA 6 mths out(PH) 6 mths out(TA)
Zin 3.79 5.25 3.69 6.75
Pino No. 3.45 6 3.4 6.3
Tuscan 3.51 6 3.53 6.5

I just bought a new test kit and followed the instructions except I measured with a PH meter to 8.2.
As for the TA kit, it says to add 15 ccs of wine, dilute to rose, add 3 drops of indicator, then add Naoh til the color changes...... I used the PH meter to measure when it hits 8.2 instead. The kit didn't give instructions for using the PH meter, that isn't a problem is it?

I am assuming I am doing something wrong measuring my must. So how do you prepare or measure your must prior to fermentation?

Thanks for the help

I'm guessing that you are concerned that pH went down or stayed the same through AF / MLF, when you expected to see a rise, and the inverse for TA. Your final numbers actually look pretty good, probably just need some minor adjustments according to taste. Personally, I view the measurements taken of must are merely a guide for major adjustment needs. Unless you take some time to pull out some must, blend it up, and strain the juice for use in sampling, there is some potential for slight variance. There's still lots of goodies locked up in the grape pulp and skins that aren't in the equation when you just mix the must and pull out a small sample..

Post fermentation number, to me, are much more dependable, as all of your goodies have been unlocked and distributed through AF and pressing. Those are the numbers I typically have more faith in.

Your six month numbers look pretty stinking good, I'd be happy as a clam to have had them on some of my recent batches, which were high BRIX, high pH and low TA.

 

[zadvocate]

I listened to a winemaker from Sonoma speak that all he cares about is PH and if he needs to adjust it, he would do that pre ferment. He felt it was no good to adjust acid after fermentation. So I would like to come up with a process to insure as accurate as possible numbers preferment.

 

[user 36973]

I listened to a winemaker from Sonoma speak that all he cares about is PH and if he needs to adjust it, he would do that pre ferment. He felt it was no good to adjust acid after fermentation. So I would like to come up with a process to insure as accurate as possible numbers preferment.

Using your pH meter to measure the endpoint of the titration is the way to go rather than going off of visual endpoint. You'll also want to get a burette if you don't have one so you can more accurately know your NaOH additions.

It is best to make the acid adjustments prior to fermentation so the flavors can integrate better but like johnd says, there are acids and potassium locked up in the cells of the grape skins that the yeast will release during fermentation. I agree that any prefermentation numbers of a must is only a rough estimate.

The pH affects the activity of yeast, bacteria and effectiveness of sulfites, so it is important to know from a chemistry standpoint. However it is the TA that you will taste and that you will need to adjust to meet your tastes (while keeping an eye on the pH to make sure it doesn't go out to lunch). California winemakers generally worry about having too little acid (and a high pH) while those of us growing hybrids worry about both.

 

[Ajmassa]

I listened to a winemaker from Sonoma speak that all he cares about is PH and if he needs to adjust it, he would do that pre ferment. He felt it was no good to adjust acid after fermentation. So I would like to come up with a process to insure as accurate as possible numbers preferment.

I don’t know why but wine chemistry is incredibly interesting to me. It’s like there is no end to expanding your knowledge. I find myself reading articles about acid or nitrogen or so2 for freaking fun! I’ve completely nerded out! But I think I’ve learned some stuff that could be helpful here. .
If the kit instructs to add 15mL of sodium hydroxide I’m assuming it’s .2N. (I switched now to .1n. It requires only a 5mL sample which can then be diluted with water since it’s neutral for easier testing) 15mL tends to be a lot when pulling from a topped up carboy. And .1n uses 30% less NaOH than .2n. No biggie but running out at a crucial point sucks.
Using the meter i think is more accurate because as you get over 7.5ish ph your basically already there and only adding small drops to get up the last few ticks to 8.2. By color change is a pain IMO.
I’ve also noticed fermentation can shift the numbers any which way from must to post AF. I guess it depends on many factors. Ive had it rise, remain the same, and drop after AF. But I learned a hard lesson to now ALWAYS adjust the must if ph is higher. Last fall I let it ride at 3.9 and created so many more problems later. Even if the must numbers are “rough”, dialing ph in closer to the target is now near the top of my priority list.

 

[Ajmassa]

I’ve heard a couple different commercial winemakers say the same thing about ph. One even went as far to say his magic number is always 3.62 for red wine (under 3.65 with cushion) and TA isn’t a factor to him at all. Still measuring TA but only to make sure it’s not way out of wack. And all decisions are mainly based on ph. (Dealing with Napa grapes)
And Always carefully adjusting the must when needed. Same varietal from same vineyard can have a drastic difference in how much ph moves from the exact same amount of tartaric added year to year. Many variables affect it.
If we overshoot, which is easily done, and acid removal is needed later on?- Learned a couple tips recently. Using potassium bicarbonate (unsure about calcium antacids) 3.65 is the seesaw point as we know. And after adding K-bicarbonate and putting through cold stabilization the acid tartrates will drop out and TA will lower- and ph will rise- if it was over 3.65. But ph will drop if under 3.65ph(preferred for stability). But the kicker I learned was that this is only the case for true cold stabilizing—in the 25-45°F range. But if temp is around 50°s-60°s it really isn’t cold stabilization. And your ph won’t move based on the 3.65 idea. It’s really just cold “settling” at that point.
So a wine at .9g/l TA and 3.25 ph- and had K-bicarb added to target, say .75g/l , and then dropping temp to ~50° — your ph won’t go against the grain and drop even lower to an uncomfortable range like 3.1. Instead getting closer to 3.40 -in the direction in typically moves when TA lowers.
Also I learned a good tip about removing acid from a must using K-bicarb. And after putting it through low temp CS for a few days the majority of the available nitrogen will be eaten up. No more YAN. In this case the ‘grape must’ needs an extra large nutrient bump for the yeast to go to work.
Sorry for the crazy long post. I just figured the tartaric dosing, CS temps, and YAN thing are all beneficial to know and wanted to share.

 

[Johny99]

All good notes above. I’d add make sure you wait a day or so after crush to test. Lots of books explain why, skins and pulp and stuff.

I’ve heard of folks putting the must through a blender then through a coffee filter instead of waiting. Haven’t tried that myself.

 

[zadvocate]

Great reply’s all thanks.

 

[zadvocate]

So it seems to me that the issue I am struggling with is TA accuracy preferment and I really dont need to be. PH is what I will focus on preferment. As Ajmasaa mentioned I would only be concerned if the PH is way high. Thanks again.

 

[Ajmassa]

So it seems to me that the issue I am struggling with is TA accuracy preferment and I really dont need to be. PH is what I will focus on preferment. As Ajmasaa mentioned I would only be concerned if the PH is way high. Thanks again.

I think that sounds about right. Obviously all within reason. A good TA doesn’t mean squat with a super high or super low ph. I’m going to start using that mindset but still keeping one eye on TA. Everything I make seems to be low on acid (only my chilean grapes had legit acid). Will keep ph high enough for the malo, and low enough so there’s protection. (3.62- my magic #). It’s easy to lose sight of the big picture when messing with TA to the must- for me at least. Plus through the magic of science it somehow rises from crush to post MLF. Hindsight 20/20

 

[mainshipfred]

I agree with the TA comments. In my wine class the winemaker said he didn't care about TA only Ph. The only time he cared abiut the TA was if he trying to create a buttery wine through MLF and then his main concern was the amount of Malic.

 

[Johnd]

TA is important when you get closer to the finished product, and should be considered as you are finishing your wine. Getting your pH in line to ensure low stress on your yeast and MLB during alcoholic fermentation and MLF should be a concern with must measurements and adjustments. You don’t need to ignore TA, but don’t focus on it so much that you end up dropping your pH too much for a good AF and MLF.

 

[user 36973]

I agree with the TA comments. In my wine class the winemaker said he didn't care about TA only Ph. The only time he cared abiut the TA was if he trying to create a buttery wine through MLF and then his main concern was the amount of Malic.

Winemakers working with vinifera in California are only worried about pH because the TA is already (too?) low and the a high TA usually means higher malic which MLF tends to make the diacetyl buttery notes. West-coast winemakers live in an echo chamber filled with the sounds of them patting themselves on their backs for how great their wine is. Yet they freak out when dealing with a colder summer that doesn't drive down tartaric acid as usual and actually have to dust off their winemaking books.

If you are working with hybrid grapes then the TA is a real issue because you may have high amounts of tartaric as well as malic.

 

[Ajmassa]

This is specifically being spoken about in terms of prepping your must for fermentation jgmillr1.
Regardless of where the grapes are from. The reason we know how Napa winemakers are doing their thing is because they’re the only ones who get interviewed that we have most exposure.
But that doesn’t change anything. If I’m at 3.6 ph I’m ready to pitch. Whether it’s 4.5ta or 9.0ta.
Why mess with it and jack up the ph ? It’s gonna move. And must numbers are not 100% reliable anyway
After AF and MLF if my ph is still hanging safe, I can afford to remove some with CS and let ph drop a little. If adding then doing by taste while keeping ph in safe range. It still all revolves around Lord Ph.
Wouldn’t that still be the case for hybrids? I am ignorant to anything not red vinifera. What would you do differently with hybrid must levels? Logic tells me that you still have to be mindful of ph 1st and foremost.

 

[Johnd]

West-coast winemakers live in an echo chamber filled with the sounds of them patting themselves on their backs for how great their wine is. Yet they freak out when dealing with a colder summer that doesn't drive down tartaric acid as usual and actually have to dust off their winemaking books.

Perhaps someone should just go on out there and show them how it’s done.........

 

[cmason1957]

This is specifically being spoken about in terms of prepping your must for fermentation jgmillr1.
Regardless of where the grapes are from. The reason we know how Napa winemakers are doing their thing is because they’re the only ones who get interviewed that we have most exposure.
But that doesn’t change anything. If I’m at 3.6 ph I’m ready to pitch. Whether it’s 4.5ta or 9.0ta.
Why mess with it and jack up the ph ? It’s gonna move. And must numbers are not 100% reliable anyway
After AF and MLF if my ph is still hanging safe, I can afford to remove some with CS and let ph drop a little. If adding then doing by taste while keeping ph in safe range. It still all revolves around Lord Ph.
Wouldn’t that still be the case for hybrids? I am ignorant to anything not red vinifera. What would you do differently with hybrid must levels? Logic tells me that you still have to be mindful of ph 1st and foremost.

The big thing I find is that the pH is never in a "good" range, usually high by vinifera standards, ta is almost always high. As noted both malic and tartaric are high. But, I usually just shoot for a somewhat reasonable pH and ignore completely the TA.