ACID %

Hi gang, Been making my own wine for quite a few years, but I just got serious about supplying all my beverage needs myself. My question is this: Books on the subject say the must should be ".60-.80% acid as expressed in tartaric acid". What I'm wondering is if it is better to err on the high side, as I've read that some acid is metabolized by the yeast so that as it ferments you have less acid with a less effective/complete fermentation, OR if running things on the low side is better? Anyone want to chime in with what percentage of acid, expressed as tartaric, you shoot for? I ask this because I've had a few batches turn out with plenty of sugar left over. I go for 13% alcohol and wind up with 11% and sweetness to boot. Bob

Reply to
Bob
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Hi gang, Been making my own wine for quite a few years, but I just got serious about supplying all my beverage needs myself. My question is this: Books on the subject say the must should be ".60-.80% acid as expressed in tartaric acid". What I'm wondering is if it is better to err on the high side, as I've read that some acid is metabolized by the yeast so that as it ferments you have less acid with a less effective/complete fermentation, OR if running things on the low side is better? Anyone want to chime in with what percentage of acid, expressed as tartaric, you shoot for? I ask this because I've had a few batches turn out with plenty of sugar left over. I go for 13% alcohol and wind up with 11% and sweetness to boot. Bob

I forgot to mention that =most= of the wines I make are =not= grape wines. I do a lot with various fruits, and also meads. Sooooo, I am adjusting pH with acid blend, malic, citric and ascorbic IIRC.

Reply to
Bob

I don't think that it is the acid causing your ferments to stop early. More likely it is lack of nutrients.

As far as getting the right acid, I would rather shoot low and then adjust at the end of fermentation. You can adjust to taste at the end and that is the most important thing. You cannot adjust to taste at the beginning as the sugar masks the acid. If you find that you are always adding more at the end then for future batches you can add more at the beginning. The important thing is to make the wine that you like. Not one that fits the mold of standards.

Ray

Reply to
Ray

Bob,

Actually, that depends on the yeast and the environment (e.g. pH, nutrients). Yeasts also *produce* acids during fermentation. With non-grape wines, the production of acid during fermentation usually tends to be *higher* than the metabolism of acid by the yeast (except in cases where the yeast is particularly efficient at metabolising acids - e.g. strain 71B-1122) plus tartrate precipitation doesn't tend to occur unless a significant amount of the acidity in the must was tartaric (i.e. by using acid blend or tartaric to acidify the must).

It's highly unlikely that a stuck fermentation would be the result of acid *production during fermentation*. However, musts with very low pHs tend to assist in causing sticking. (On that, fermentation temperature and yeast nutrients are more of an issue.)

Ray suggested the easiest method - to adjust acidity post-fermentation. Some winemakers feel that by doing that the acidity somehow doesn't "integrate" so well into the wine, others disagree. The acidity of the must *can* be adjusted pre-fermentation, by knowing roughly where it's at (measuring the TA) and where it will go (estimates of acid production during fermentation), a reasonably accurate estimate can be made. The TA of the must can then be adjusted based on the final level.

Where the TA should be pre-fermentation really depends where you want it to end up, and that depends on the style of wine. For example, a non-tartaric must has TA of 6 g/l (0.6%) and a pH of 3.3. The final wine will not go through MLF. It's desired to have a final level of 6 g/l. Estimated TA increase during fermentation is 2 g/l. Thus, the must's TA will need to be dropped by 2 g/l (chemical deacidification). Alternatively, a yeast strain like 71B-1122 or MLF could be used.

Ben

Improved Winemaking

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Reply to
Ben Rotter

So you suggest adding yeast nutrient powder? I'm using a pretty good amount of juice in my must; I rarely add any water!

I think you have given me a plan; I think I'll try adding some acid and nutrient powder as fermentation slows. I keep an accurate log of how many bubbles per minute are coming out of the airlock. It gives me a nice picture of what's what. Thanks! Bob

Reply to
Bob

I would suggest adding the nutrient up front. The yeast will utilize much of it early on during the reproductive stage. You do want them to use it up rather than leave it in the wine.

Ray

fermentation,

Reply to
Ray

Ben, I agree that it is best to have the acid in the must up front so it all integrates properly, but I don't feel that small adjustments are a problem at the end and I hate trying to bring it down. I want to be close but I would rather take it up a bit at the end. I will generally do what I suggested. I aim low the first time I make a new wine. Keep records and adjust the amount of acid I add when I make it again. Really, after making a wine a couple of times, I rarely have to adjust it at the end. Or not much anyway.

Ray

Reply to
Ray

One comment on meads since Bob mentioned that; my acid always rises and pH drops as it ferments. I usually add juice of half a dozen or a dozen lemons to 6 gallons (US)and it seems to end up around 6 to 6.5 g/l with a pH of 2.8. That pH would lead you to think it's tart, but I usually end up doing as Ray says, touching up the acid (upward) at the end, at least on mead. All honey is different results vary. Regards, Joe

Reply to
Joe Sallustio

An EXCELLENT point! Thank you sir!

Reply to
Bob

Honey is =hugely= variable! Nothing about it is ever the same. Only a brand name like Sue-Bee is even close to the same. Every batch of mead for the last 25 years has been different. What I do as it finishes fermenting, is drop in campden tabs to kill off stuff, and add 5 whole =cloves= per gallon, let it settle to clarity, rack it off the lees and put preservative into the fresh carboy and let it go another year at least. Not many other hobbies take so long to see results!

Reply to
Bob

Sure, it's the most c> dozen lemons to 6 gallons (US)and it seems to end up around 6 to 6.5

Are you talking about dry mead here?

Ben

Reply to
Ben Rotter

I didn't say it wasn't variable, I would not argue that. Mine is not that unpredictable since it comes from the same hives each time. Fall flow and spring flow are different as you would expect. The point I was getting at was that wine and mead behave differently during fermentation. My mead pH drops an order of magnitude, it really suprised me the first time. Regards, Joe

Reply to
Joe Sallustio

I recently read "The Complete Meadmaker" by Ken Schramm. In it he suggests that for mead you should not try to adjust the pH and acidity before you ferment. It seems that mead has natural buffers that will effect the way the acid ends up in strange ways and that if you try to adjust acidity up front you can end up in a place that you did not want to go and that you may even cause the mead to stick. This is all from what I read. I know that in my last batch of mead I thought I adjusted it up front and when if finished I was way far away from what I expected and I had to add a lot of acid.

Ray

Reply to
Ray

For the most part, it usually ends up around 12% ABV and 2% RS. It's not really sweet. We use between 12 and 14 pounds of honey to 5 gallons (US) to make around 6 gallons preferment. Regards, Joe

Reply to
Joe Sallustio

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