What to do with these Grapes ?!

[hector]

Hi there !

The only type of red grapes available to me are the table ones from the stores . They are high in TA and

after crushing the pH is 3.6 .

I always add 100 ppm SO2 after crushing and let it sit for 12 Hours and then add Pectic enzyme and

let it sit for 24 Hours , then I check the pH again .

Last time I did this Procedure , the pH was 3.1 at the end , so I brought it up to 3.4 by adding Potassium Carbonate .

As I siad , These grapes are probably high in TA because the pH drops NON-STOP even to below 3.0 and I have to

add more and more Potassium Carbonate each time

As far as I know , adding too much of this salt can lead to a wine with very low tartness . On the other hand , as the pH does

not remain in the appropriate range , there could be some problem with the flavor extraction and the yeast would be also in

Stress and it would emit H2S ( As I had this problem each time ! )

Now , can any one tell me , how would it be possible for me to solve this problem ?!

Hector

 

[djrockinsteve]

You can cold stabilize the wine and drop out some of the tartaric acid. You can blend this wine with another wine with a lower ph/acid%, even if it was a bottle store bought.

 

[Wade E]

Where are you from?

 

[hector]

You can cold stabilize the wine and drop out some of the tartaric acid.

You are right , but this problem exists in the first days of fermentation in the Primary .

By my previous batch , I smelled H2S on the second day of fermentation . I checked the pH and it was 2.8 !!!

Although , I had already adjusted it to 3.4 before pitching .

I think "cold stabilization" should be done just before bottling .

Hector

 

[hector]

Where are you from?

I live in the Middle East .

Hector

 

[arcticsid]

"so many grapes, so little wne"!

Hope you can make the best of them bro

 

[hector]

Hope you can make the best of them bro

I would like to , but I have always problem with adjusting the pH .

Hector

 

[Wade E]

Hector, what are you testing the ph with cause 3.4 to 2.8 is an extreme difference and it sounds to me like you are getting bad readings. Have you ever done a few tests on the same must at the same time? Im betting what you are using isnt that accurate. Ive never seen a change like that.

 

[hector]

Hector, what are you testing the ph with cause 3.4 to 2.8 is an extreme difference and it sounds to me like you are getting bad readings. Have you ever done a few tests on the same must at the same time? Im betting what you are using isnt that accurate. Ive never seen a change like that.

I use an accurate pen pH meter and I calibrate it using buffer solutions .

I've been using it for two years and it was always accurate .

I've always had this problem by my previous batches . I thought that could be because of the pectic Enzyme functioning slowly , therefore I let the Must sit for 24 Hours after adding the Enzyme , so that it has enough time to break down all the cells and most of the acids will be released into the Must .

As I said , I did so and the pH droped from 3.6 to 3.1 . Then I adjusted it to 3.4 by adding Potassium Carbonate and pitched the yeast . But , after 2 days I smelled H2S and it was down to 2.8 this time ! The yeast was in Stress and emitted H2S because of very high concentration of acid .

The only option I have is to check the pH several times each day and add more Potassium Carbonate , but it has also disadvantage ( flabby taste of the wine ) .

What do you think abou it ?!

Hector

 

[Arne]

I do not know if this would work or not, but I would try a small batch, do everything including check ph, but do not adjust it. Ferment it out and check the ph at the end, adjust it then. Just a sugestion. Arne.

 

[hector]

I do not know if this would work or not, but I would try a small batch, do everything including check ph, but do not adjust it. Ferment it out and check the ph at the end, adjust it then. Just a sugestion. Arne.

I always make small batches ( 1.3 Gallons ) .

You probably didn't notice what I said .

By such a low pH , the yeast would be in Stress and it emits H2S , as it happened to me by previous batches .

I believe that pH must be adjusted prior to pitching .

Hector

 

[grapeman]

I think you need different grapes. Also to help reduce H2S, add some yeast nutrient. If you think the pectic enzyme breaks things down too much and reduces the pH, stop using it. If you are beginning with a pH between 3.2 and 3.6 you should not need to add the carbonate. Try a small batch and work it less and I bet it turns out better. Possibly what you think is H2S is just the smell of fermentation.

 

[hector]

I think you need different grapes. Also to help reduce H2S, add some yeast nutrient....

Thanks for your reply .

As I said before , these grapes are the only one available for making red wine .

If I use other grapes , that will lead to a rose wine and I don't like it .

I always add yeast nutrient according to its instruction ( 1 teaspoon per Gallon ) and my batches are

always small ( 5 liters = 1.3 Gallons ) .

By my previous batch , the pH of the Must was 3.6 just after crushing , but it drops always to around 3.0 or

even lower after 24 Hours . Therefore , I have to use Potassium Carbonate .

By the way , I'm familiar with different smells including H2S . In fact , I studied Chemistry at university .

Hector

 

[grapeman]

I use grapes naturally very high in acid and I can say that I have never seen anything drop from 3.6 to 3.0. Even if it did, I would let it ferment and adjust later. I do not believe we have any magic bullet for you.

 

[hector]

I use grapes naturally very high in acid and I can say that I have never seen anything drop from 3.6 to 3.0. Even if it did, I would let it ferment and adjust later.

O.K. , but then I should deal with another problem ( H2S ! ) if I let it ferment with such a low pH .

Hector

 

[Runningwolf]

Hector did you do a copper test?

 

[hector]

Hector did you do a copper test?

No .

If I could be able to solve the pH problem , there would be no H2S case .

Hector

 

[grapeman]

You seem to believe for whatever reason that a low pH means H2S. I just do not find that through experience. Proper yeast selection minimizes H2S. I do thousands of gallons of wine, not carboys of it, so I do have a bit of experience.

 

[Runningwolf]

Hector you have not told us what kind of grapes you are using yet. Have you asked your local wineries or supply houses. Are you legally allowed to make wine in Iran??? I would maybe suggest you ask someone familiar with the grapes you are using in your country. Please share the solution with us so we'll know for future reference. It is my understanding that there are some very skilled Iranian Winemakers even though alcohol is forbidden.

 

[Wade E]

Like grapeman said, ph and ta do not really have anything to do with H@S although they can contribute in certain situations. The main reason for H2s is improper nutrients for the yeast or low 02 levels for your yeast to thrive in. Some of these yeasts are notorious fpor this H2S problem like Red Star Montrachet but I use it all the time and with proper nutrient levels and plenty of 02 I dont have any of these problems. Also, it has been noted now to wait until fermentation has sarted before adding most or any of yoir nutrient.