How to rescue the batch of wine having high acidity?

[Bijendra Lal Dangol]

Help!!! Help!!!
I have a batch of wine which has been about 1 year and few months. It was all good as fresh batch of wine tastes. But it tastes so much acidic having 0.50 gm/100ml as citric acid few months ago. After realizing its high acidity, i even treated with KMS inorder to stop its acidity if it may be due to cross contamination. Now, i have checked its acidity and its almost 0.62 gm/100ml as citric acid. It tatses so much acidic. What can be done to rescue this batch? Hope for the best solution from you.. thanks in advance..

 

[Kentuckyhomebrewer]

you could try adding some potassium bicarbonate. Or maybe blend it with another wine or juice?
If it's been contaminated I don't know if there's much you can do, or if you'd even want to in that case.

I'm no expert though so might want to see what the rest of the group thinks

 

[NorCal]

I would do bench trials (small glass sized batches) with potassium bicarbonate to see if it is effective in neutralizing the acid to a point the wine is drinkable.

Here is a link to a thread a few years ago, showing how I did the trial :

For the first time in my wine making career, I am dealing with a wine that is too tart to my liking.

 

[4score]

He has had the wine aging for over a year and suddenly notices the acidity is spiking. What could be the cause - I haven't seen this?

Bijendra is a winemaker in Nepal and currently is dealing with this problem for a LARGE batch of wine (over 3100 gallons)!

 

[4score]

Bijendra, what is the pH of the wine? What is the current ppm of SO2?

 

[Bijendra Lal Dangol]

@4score The current ppm of SO2 is just about 25 and i can not assess the accurate pH of this wine due to error in the pH meter but i think it must be below 3

 

[NorCal]

Could the change in TA be attributable to lab error from one reading to the next? Are you adding pure SO2 or does it have citric acid included? How does the wine taste, are you noticing any VA (volatile acidity), taste like sherry or vinegar?

 

[Bijendra Lal Dangol]

@NorCal I am sure about that there is less probability of lab errors and even i have repeated the same test for number of times repeatedly for the confirmation. And i am using KMS as the source of SO2. The one thing was i am unable to maintain the required so2 content sue to the pandemic Covid-19 so i am about 4 months away from my workplace as a result it happens... finally it tastes so much acidic but smells acidic too but i am not sure it smellls like a little bit vinegar or not...

 

[Rice_Guy]

VA is a very good guess, do you have a neighbor to cross check with? In the lab the ladies tend to be better tasters.

Could the change in TA be attributable to lab error from one reading to the next? Are you adding pure SO2 or does it have citric acid included? How does the wine taste, are you noticing any VA (volatile acidity), taste like sherry or vinegar?

 

[Bijendra Lal Dangol]

@Rice_Guy if it so then i would even send samples to neighbouring lab for cross checking but i think during this time of pandemic, it would not be possible...

 

[NorCal]

Are the vessels air tight and kept filled to capacity? Grape wine? What varietal?

 

[Bijendra Lal Dangol]

@NorCal Exactly the main problem is in our storage tank is even the tank is closed with the lid tightly but air can escape inside the wine and the tank was of stainless steel with out any jacketed cover and temperature control plus the wine was not filled with its full capacity.

 

[Bijendra Lal Dangol]

@NorCal I have just analyzed the sample from the neighbouring lab and i have got thr following results:
Batch Acidity PH
1 0.6976 3.48
2 0.62 3.55

The next thing i have obseved that TSS of the wine is reduced to 4.4 degree brix while it had about 6 degree brix before at the time of racking. And the alcohol content is calculated as 11% that is higher than usual.

 

[user 36973]

If acetobacter is present in the wine and slowly turning it to vinegar, sulfites will NOT stop or control it. You'll need to filter the wine through sterile (EK) pad filters to remove it. This is the quickest way to stop the process so you can evaluate the wine and decide on next steps.

 

[NorCal]

Post removed - I lack the full understanding of what is going on to be of assistance.

 

[Bijendra Lal Dangol]

@NorCal By the way I usually the backsweeten the every batch of wine when the TSS gets constant. I mean we are making sweet wine so i usually backsweeten the wine when it usually gets constant at about TSS 5-6 degree brix. That wine which gets high acidity was actually gets its TSS constant at 6 degree brix few months ago but when i observe its TSS today and it was about 4.4 ac according with Refractometer but the specific gravity was same as that of before.
The next thing you have told that filtering through Reverse osmosis which is not possible in my winery but filtering through cartridge 0.45 micron and even 0.22 micron is possible.
i have some ideas based on my context and i would like to share and please suggest me which would be possible and better:
1) Blending the acidic wine with wine having low acidity making final wine with desired acidity.
2) Treatment with neutralizer either CaCo3 or Potassium bicarbonate??? and if it tastes not good then blend with other after treatment.
And the main thing is how to save the wine till the bottling time either
a) pasteurize and keep air tight
b) filtering through cartridge with 0.22 micron
c) just treat with double dose of So2

 

[Bijendra Lal Dangol]

@jgmillr1 is there any methods to evaluate the presence of acetobacter or high acidity due to acetic acid fermentation? It smells more acidic but i think i am just confused either it smells a little bit of vinegar or not....

 

[user 36973]

@jgmillr1 is there any methods to evaluate the presence of acetobacter or high acidity due to acetic acid fermentation? It smells more acidic but i think i am just confused either it smells a little bit of vinegar or not....

A microbiologist could identify if there is acetobacter in a wine sample.

You can determine the amount of vinegar in the wine by using a "cash still" and titrating the distillate. There are government limits on the amount of allowed vinegar in wine, so this is a good idea to measure anyway.

The only acids that have an odor are the volatile ones, and that is a bad sign.

I agree with @NorCal that you should determine if the wine is worth saving. Pad filtering down to 0.45um can be done in a day for $100USD. I'd go with that first since it is quick and cheap. That will give you time to do more analysis and decide on what to do with it. You'd want to absolute membrane filter the wine prior to bottling anyway.

Be careful with blending it into other wine. A faulted wine is easy to ruin another good wine with and double your trouble.

 

[Bijendra Lal Dangol]

@NorCal @jgmillr1 it smells exactly like nail polish remover..

 

[Rice_Guy]

@Bijendra Lal Dangol this is an interesting problem to fix.
* Acetobacter is possible to test in a microbiology lab, at this point if it is infected we are looking for a cure which is filtering with a 0.45 micron absolute cartridge. RO is over kill.
* I am not aware of a cure for ethyl acetate (nail polish remover). RO will not remove it. Ultrafiltration will not remove it. It is not a polar molecule so I don’t think a resin cartridge could pull it out.
* TSS,,, I assume you were testing total suspended solids, in the US industry we usually would not look at this number.
* If this batch is 3.1K gallons, (post #4: 11,800 liters) the folks at the universities have tools that may help, the US experts are at University California Davis and Cornell University, Australia has a wine research institute which would be closer to you.
,,,, Maybe someone out of the US has better technical references. ,,,,,

The key may wind up being able to diagnose what happened so it doesn’t happen again.