I think my acid level is high?

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

LJPelletier

Senior Member
Joined
Nov 12, 2011
Messages
194
Reaction score
1
So I just finished pressing the juice from a ton of chardonnay grapes that I just picked. It is very late in the season to be picking them... would that be why the acid level was so high?

Doing the test, my results showed me an acid level of 12g/L.

The SG reading was 1040 which showed potential alcohol of only 5%, so I added about 2kg of sugar mixture, and now it is bumped up to 1100 (potential 14% alcohol).

I have tartaric acid, which I was expecting to have to add to bump up the acid content, but it is obviously not needed... should I buy something to reduce the acid content and add it now, or just wait for fermentation and worry about it later?

:n
 
High acid and low sugar would indicate unripe grapes. What is the pH?
 
5% potential alcohal is CRAZY low for a San G.

As jet said, Acid and sugar are at the opposing ends of a balance scale. The more unripe a grape is, the more acid (and less sugar). The more ripe a fruit is, the more sugar (and less acid).

Think of it this way. The vines are using acid to combat bacterial infection. The high acid protects the fruit until the fruit is mature and ready to spawn offspring. Once mature, the acid drops and the sugar increases to either provide the new plant with food/neutriants or to attract animals that might spread the seeds.

I would check the acid level of you wine via a PH meter / TA kit / or simply PH strips. I would bet real money that you will need to lower the acid level.

Have you tasted it?

johnT.
 
Little unusual readings for this late. For a Chardonnay to harvested this late i would expect the readings to be high in sugar and low in acid.
 
Little unusual readings for this late. For a Chardonnay to harvested this late i would expect the readings to be high in sugar and low in acid.

I am very new to this, but it is possible I made an error. To test the acid, I used a kit that had me take 15ml of must, add 3 drops of phenolphthalein, then add sodium hydroxide 1ml at a time until complete colour change to pink. It took 12ml to change the colour, showing me results of 12g/L.

The sugar reading, I got with a hydrometer which I hope is working properly, as I bought it used.

I did not taste the must, and have now added the yeast, so I'm not so sure I should be tasting it until primary is done.

Will the high acid content affect the primary fermentation, or should I be adding acid reducer ASAP? I'm about 10 hrs into primary fermentation and it looks and smells like I've read it is supposed to. Strong yeast smell and lots of foamy yeasty stuff on the top now.

Also, I have read conflicting information about primary fermentation. Some people stir it once or twice a day, and some people say not to even touch it. Which is better?
 
This posting might be a little bit late as you are probably already fermenting, but if you were to use lalvin b71 1121 yeast, it would eat up a good part of the malic acid.
I don't know by how much your acid level would drop because malic acid is not the principle acid in your case but it certainly would help.
 
Is your sodium hydroxide .1 or .2 ?

In your test if you are using NaOH of .1 then your TA is 6 not 12

Check you #'s HERE
 
Last edited:
Do yourself a favor and buy a pH meter to get your acid readings. I tried the swirly color change garbage test and it is very prone to error. Using a pH meter is almost fool proof. Check out the tutorial section here, it saved my bacon.
 
If your pH is extremely low, it can adversely affect your primary fermentation. Also unripe grapes usually have a disproportionately high malic acid, so consider doing a MLF.
 
Is your sodium hydroxide .1 or .2 ?

In your test if you are using NaOH of .1 then your TA is 6 not 12

Check you #'s HERE

Good point.
If you have some tartaric acid on hand and have access to a gram scale, you can make up an acid sample to test your NAOH solution.
As an example, if your were to add 5 grams of tartaric acid to a litre of distilled water, then you should get a TA reading of 5 with your test kit.
 
Last edited:
Good point.
If you have some tartaric acid on hand and have access to a gram scale, you can make up an acid sample to test your NAOH solution.
As an example, if your were to add 5 grams of tartaric acid to a litre of water, then you should get a TA reading of 5 with your test kit.

Distilled water?
 
The sodium hydroxide solution is 0.2 N

Yes, I am already fermenting, using Lalvin EC-1118. It was the only wine yeast they had at the place I bought my supplies.

I can not afford to buy a PH meter right now, but will look into it before doing this again. :)

When I was looking for a chardonnay recipe online, I found one that suggested malo lactic culture... I imagine they sell that in most wine supply stores? Is it easy to use? Is there any risk of messing things up by trying to use it? (or not use it for that matter)

The recipe I was looking at suggested to add the malo lactic culture on the 5th day of primary. Is that about right? Anything else I should know about malo lactic culture?
 
Your LHBS almost certainly carries one or two of the more common strains of MLF bacteria. MLF bacteria are sensitive to high alcohol, high SO2 and low pH.
 
Your LHBS almost certainly carries one or two of the more common strains of MLF bacteria. MLF bacteria are sensitive to high alcohol, high SO2 and low pH.

Okay, so I should definitely raise the pH before adding any MLF? How do I know if the SO2 or alcohol are too high to use MLF?
 
It stands to reason that if the SG is as low as 1.040, the acid is likely very high, so his acid reading is probably close. (That is amazing for this time of year.)

Alcoholic fermentation should drop your acid by at least 1. That should raise your PH a little. Your PH is definitely going to be well below 3.4.

MLF should drop acid another 1 to 4 points.

If your PH is too low, you will have to use a special MLF bacteria that can stand a very low PH. MoreWines sells CH35 (I believe), which can go with a PH as low as 3.0.

Take a look at the specifications for the bacteria you intend to use and make sure it can withstand a low PH. I doubt it can, so you will likely have to order the special bacteria.

If you are going to get into MLF's, you really, really do need a PH meter. If your LHBS has a meter, see if you can take a sample to them and have it checked.
 
One more thing. When this wine is finished fermentation, if the acid is really that high, since you adjusted sugar to an SG of 1.100, your wine is going to taste sweet, even if the final SG is 1.000 or lower. That is because high acid with high alcohol makes the alcohol taste sweet. Once you get the acid down (with potassium carbonate or however), it will no longer taste sweet.

If your starting SG is 1.100, the potential ABV will be about 13.6%, which is acceptable for most mlf bacteria.
If you are going to do an mlf, don't add any more Kmeta until after mlf is done. You will need to purchase a chromatography test kit to determine when mlf is finished.

You really need that PH meter...
 
Hmm... well I phoned around Abbotsford, and nobody has any ML bacteria, let alone a special strain that will withstand high acid levels. I guess I will not be trying MLF this time around. No time to order it on the internet, as it wouldn't get here for prob a couple weeks.
 
If you're going to make wine from grapes, a pH meter is absolutely essential. It is as important as, if not more than, TA testing.
 

Latest posts

Back
Top