Difficult numbers with malic musts

If the must is high in malic acid, I think an MLF would be in order. Cold stabilization only percipitates out tataric salts.

I recall reading something about different carbonates taking out different acids but I can't really provide any information since I don't really remember what I was reading, sorry.

MLF is a potentially problematic solution because when >80% of your acidity is malic you have to do a partial MLF. This is risky without sterile filtration (which most of us non-commercial winemakers don't have). (Anyone know anything about the effectiveness of stopping MLF by adding lysozyme to a cultured, vigorous MLF?)

If you deacidify with a carbonate you take the pH to an unacceptable level - this is not a practical solution.

Double salt precipitation (where you raise the pH to drop out calcium tartrate malate) is not helpful with a must where you don't have tartaric either.

I appreciate the response, but I was really looking for specific solutions which targeted the above mentioned problems.

Ben

Ben Rotter wrote in "If you deacidify with a carbonate you take the pH to an unacceptable level - this is not a practical solution."

Ben - Consider dividing the wine into two fractions. Fraction 1 would contain the amount of acid you want to remove from the wine. Fraction 2 would contain the desirable amount of acid for the entire wine. Totally deacidify Fraction 1 with carbonates. When the reaction is complete and the wine has settled mix the two fractions together. If pH is too high to begin with make that adjustment before you begin.

Bill Frazier Olathe, Kansas

It depends somewhat on whether it's a red or white wine, but I'd probably hit it with tartaric to get the pH down to something reasonable (3.3?), ferment it and let the ML go. I'm not a big fan of ML inhibition. I want my wines to be stable without having to sterile filter or oversulfite them.

Tom S

Thanks everyone for your replies. I will reply by method:

**CARB> Consider dividing the wine into two fractions...

Does dividing and deacidifying give a significantly different pH to deacidifying it all in one go?

Are you suggesting I acidify to correct the pH and then deacidify for TA? Seems counterproductive to me.

**COLD STABILIS> How would you go about determining what percentage of your acid is > Malic?

I am working with malic fruit (e.g. gooseberries, raspberries, etc) so it's pretty certain.

As the only method that is not a practical soltuion: you can correct the pH with the tartaric acid, but once you remove it through cold stabilising (and that's assuming you even if you manage remove it all) you still have all the malic you started with.

**MLF

Tom S wrote:

Firstly, if you have a malic dominant must then you're basically suggesting you replace all that malic with tartaric and conduct a full MLF (that's the only way you'll have secure stability without sterile filtration). That is a possibility but it would change the acid profile quite a bit.

Secondly, I'm often dealing with wines I'd rather not put through MLF anyway (both in terms of the hastle of it and in terms of style), so if I can find an alternative it'd be nice.

**COMBINED STRATEGIES

I have often thought of combining strategies. For example, you could lower the pH with tartaric, then deacidify the malic portion of the TA with MLF, then precipitate some of the tartaric out by cold stabilising. But (1) this is an incredibly uncertain way of going about things with all the unknowns on the shifts to both TA and pH you'd incur, and (2) I'd rather not have to make so many adjustments (somehow it seems to "damage" the wine).

More interestingly:

(1) you could deacidifying by using yeast 71B-1122. But even that will only reduce like 20-40% of your malic, and when you have musts at >10 g/l that's just not enough. Anyone have any data on the TA reduction caused by this in malic-dominant wines BTW?

(2) you could conduct a pre-fermentation biological deacidification of malic acid by Lactobacillus plantarum. But I've only ever seen it sell in LARGE packs which I am not prepared to buy.

Lots of ideas and lots of problems. Any solutions?

Thanks for your input, Ben

Ben, I just saw this thread and I make the following comments:

- assuming that the amount of Malic present is as you say, you have been given the correct suggestions. Whether you are prepared to implement them or not, whether they are convenient or not, it's entirely your decision.

- what type of fruit and what quantity of wine are you making that you feel "compelled" to use it? Unless there is a reason, other than for discussion purposes....

- If you must use such an unripe/unsuitable fruit to make wine, then you are obviously prepared for the result: You MAY be able to make great wine from great fruit, but you WILL NOT make great wine from poor fruit. That simple.

- In your case, you do the best things you can (or retain practical), and pray for a good result:

1. add Tartaric acid to adjust pH to its minimal acceptable level (at

3.5 I would leave it alone!);

1. do a pre-fermentation biological conversion of Malic acid (there are enzymes also available);
2. use a yeast that 'eats up' Malic during fermentation;
3. provide nutrients and perform MLF (cold stabilisation may not help if there is no Tartaric);
4. encourage longer lees contact;
5. blend with another fruit, preferably overripe;
6. sweeten/stabilise the wine prior to bottling. The details of performing each step have been widely discussed in other threads.

Cheers, Giovanni.

oversulfite them.

Ben Rotter wrote "Does dividing and deacidifying give a significantly different pH to deacidifying it all in one go?"

Ben-I have a small ion exchange set up and remove all of the acid from a portion of wine when the %TA is too high (I work with high acid grapes). When the two portions are mixed back together the pH is little changed from the original. I believe this is because the same proportions of acids are still present in the remixed wine, just less of them.

"Are you suggesting I acidify to correct the pH and then deacidify for TA? Seems counterproductive to me."

You said to consider a wine with pH >3.5. My thought was to adjust the pH to a desired level. Then proceed as above removing all of the acid from a fraction of the wine. When remixed the resulting wine pH should be close to that before treatment.

Bill Frazier Olathe, Kansas

Ben, This is a tough one, just to add to a few comments; I would start with Lalvins 71B yeast, it eats malic. That may be all you need if it is malic dominant. If the TA comes down, but pH rises too much:

Plastering with gypsum is said to reduce pH without raising TA on malic musts, but can impart a bitter taste and takes awhile to come out of suspension. (Calcium Sulphate).

Margalit has a graph in 'Concepts of Wine Chemistry' that show an initial pH of 3.64; 1g/l took it to 3.59, 2 g/l took it to 3.45 and 3 g/l took it to 3.38. It's an old practic and seems to be forgottten, maybe for good reason.

I wish I had better advice, but raspberry is tough to make around here. I made one that is closer to cough syrup than wine...

Regards, Joe

Ben, This is a tough one, just to add to a few comments; I would start with Lalvins 71B yeast, it eats malic.

Plastering with gypsum is said to reduce pH without raising TA on malic musts, but can impart a bitter tastes and takes awhile to come out of suspension. (Calcium Sulphate).

Margalit has a graph in 'Concepts of Wine Chemistry' that show an initial pH of 3.64; 1g/l took it to 3.59, 2 g/l took it to 3.45 and 3 g/l took it to 3.38. It's an old practic and seems to be forgottten, maybe for good reason.

I wish I had better advice, but raspberry is tough to make around here. I made one that is closer to cough syrup than wine...

Ben, This is a tough one, just to add to a few comments; I would start with Lalvins 71B yeast, it eats malic. That may be all you need if it is malic dominant. If the TA comes down, but pH rises too much:

Plastering with gypsum is said to reduce pH without raising TA on malic musts, but can impart a bitter taste and takes awhile to come out of suspension. (Calcium Sulphate).

Margalit has a graph in 'Concepts of Wine Chemistry' that show an initial pH of 3.64; 1g/l took it to 3.59, 2 g/l took it to 3.45 and 3 g/l took it to 3.38. It's an old practic and seems to be forgottten, maybe for good reason.

I wish I had better advice, but raspberry is tough to make around here. I made one that is closer to cough syrup than wine...

Regards, Joe

I tried this (using Lalvin 71B) on apple wine a couple years ago. In my opinion, it was a big mistake. It ate too much acid and I could never get the acid balance back again.

Thanks for that. I had just assumed you'd end up with the same pH you had > you have been given the correct suggestions. Whether you are prepared to

I am fully aware of all the methods you listed (that is what all the preceding posts in this thread were about). I noted the problems (not just inconveniences) I saw in obtaining realistic/practical results with those methods. I was looking for people to bring some further thought to these rather than to reiterate the solutions I had already stated I had these problems with.

Can you shed any light on combining deacidifying strategies (successful experiences)?

Do you know from where I can order *small quantities* of pre-fermentation biological deacidification aides?

I am not blessed with perfectly naturally balanced fruit (e.g. high quality grapes) and must make do with what I have. I am fully aware of the disadvantages this has but I still want to make wine. Making the best wine possible from unbalanced fruit is one of the greatest challenges and skills of a winemaker.

Ben

Joe,

Thanks for that. That at least solves the problem of the pH problem without increasing the TA.

Is that due to a high TA or something else? Have you ever tried doing multiple deacidification stategies in parallel?

Thanks for the helpful input, Ben

Ben, I bought juice off a less than reputable vendor, when I got it home it was all fermented out. Since I had no control of that I was behind the 8 ball from the beginning. I ended up playing with it to get it drinkable and am still not there yet. Deacidification did NOT follow grape wines, the pH changed much quicker for the worse with chalk, I might try gypsum the next time. Sorry I can't be more help but I have very little experience with raspberry and such. At this point I only know what I would not do if I made it again, I would not use chalk.

Regards, Joe