How to adjust upwards ?

[hector]

Hi there !

How would you bring up the pH of a red Must from 3.1 to 3.5 , 24 Hours after adding SO2 and Pectinase ?!

Hector

 

[spaniel]

There are ways to do it with (I think) potassium bicarbonate, but I will leave that to people who have done it and know the details.

Personally, I'd go ahead and ferment it then do a MLF. Your pH may just end up where you want it. Given how much it can change, if you are anywhere in range at the start (which 3.1 typically is) I would rather deal with it at the end.

 

[hector]

Your pH may just end up where you want it. Given how much it can change, if you are anywhere in range at the start (which 3.1 typically is) I would rather deal with it at the end.

As far as I know , the lowest pH that yeast can tollerate is 3.2 , besides 3.1 is not in the range ( 3.3-3.5 ) and the fermentation itself lowers the pH .

This is and has been my Problem , because I lost two batches and I think they were contaminated with the Carbonate salt which I had to add relatively large amounts 24 Hours after adding SO2 and Pectinase .

Hector

 

[vernsgal]

I would add calcium Carbonate. I'm not sure how many Gal. you're starting with but I would add 1/4 Tsp at a time ,allowing an hour between readings so you know each addition is well mixed. I am relatively new at PH readings so this is just IMHO. I am still learning so...

 

[skipdonohue]

3.1 is too low to leave alone. If it were mine, I'd bump it up to 3.4 pre-ferment with potassium bi-carbonate .. then definitely do MLF to raise it a couple more points naturally… just do not add more SO2 to the wine before malo

 

[hector]

3.1 is too low to leave alone. If it were mine, I'd bump it up to 3.4 pre-ferment with potassium bi-carbonate .. then definitely do MLF to raise it a couple more points naturally… just do not add more SO2 to the wine before malo

I already know that I should bump the pH up , but each time I do this , it ends up on the second day of fermentation with a contaminated batch ( It emits strongly H2S and Ethyl Acetate ) . Although , enough yeast nutrient ( DAP and Brewers Yeast Tablet ) is added .

Hector

 

[skipdonohue]

How much SO2 are you adding at crush? If you are adding too much, then that factor and the low pH could cause the H2S issues.. Personally I never add SO2 at crush, if the fruit comes in good quality.. what kind of grapes are these? You probably dont even need the pectic enzymes either.. Also when you take your pH samples, scoop up some juice and skins, run it through a blender, strain, and then take pH reading and that juice.. Its more precise..

If you keep running into the H2S smell every year, change up your protocol, try a batch this way next time, I bet you wont have any issues.. less is more

 

[manvsvine]

It's unlikely your so2 addition would cause h2s , A standard 50ppm addition will even go a long way to prevent it , as it would knock down and inhibit wild yeast and bacteria

I'd look at your nutrient regime , given your numbers I'd guess your grapes are from a cold area .
Cold climate grapes are usually low in nitrogen , you should consider a better nutrient program to prevent h2s fermaid K would be much better than what you are using for preventing h2s .

Many yeasts can go much lower than 3.2 , especialy if you hydrate with goferm , build a yeast starter and then add a small amount of your must to the starter to aclimitise the yeast . Let it ferment overnight then add to your main must.

A Malic consuming yeast like 71b 1112 which is widely available or maurvin b will help reduce acid durring the ferment.

I'd do full malolactic fermentation , vp41 or vp31 are good options for high acid wines , 31 is able to get started at very low phs . Optimalo should be used .

Then after mlf if the wine is still too acidic you can cold stabilize .

If it's still too sharp you could age it for a couple months with a high dose of biolees which will soften the wine and make the acid less noticeable .

If after 6 months it's still too sharp you can blend in some lower acid wine .
And as a last chance Hail Mary , acidex can help .

 

[hector]

How much SO2 are you adding at crush? If you are adding too much, then that factor and the low pH could cause the H2S issues.. what kind of grapes are these? You probably dont even need the pectic enzymes either..

I use the 10% solution of K-Meta for adding SO2 to the Must and measure the milliliters needed due to the Table which shows pH and the appropriate free SO2 levels .

But , as it is safe to assume that 50% of the first total added SO2 will be bound and the other 50% will be free , I add double by the first time of adding SO2 .

For example , if the pH of the Must is 3.4 , we need at least 31 p.p.m. of free SO2 in order to have at least 0.8 p.p.m. of molecular free SO2 to protect the wine . Therefore , I add 62 p.p.m. of SO2 to the Must after the Crush in order to have about 31 p.p.m. of free SO2 .

Am I right ?

I'm using table red grapes and it is the only sort available to me for making dark red wine .

Why there is no need to add Pectinase ?!

Hector

 

[manvsvine]

At crush you don't need to match ph to so2 addition .
That's why a 50ppm addition is standard .

This will inhibit native fauna but allow your innoculants to proceed.

A 50ppm addition will be 100 percent bound by the end of all the punching down pressing etc because of all the o2 exposure , I've even seen 100 ppm( used on bird damaged grapes) test for zero free so2 at the end of primary .

This is a good thing because it allows you to do malolactic fermentation without issue.

http://www.morewinemaking.com/public/pdf/wredw.pdf

More wines manual is helpful

It sounds like you have some science background .
You'll like this book
http://www.amazon.com/dp/1550652362/?tag=skimlinks_replacement-20


What kind of sugar levels did those table grapes come in at?

As for enzymes , if you are useing table grapes , then they are a good idea as you'll want to pull as much flavour as you can out of those skins because table grapes produce a thin wine with little color compared to wine grapes . Ive used the concentrate from a red wine kit to chapitalise table grapes , this gave the wine much needed tannin, color and flavor .
Things table grapes are short on.

 

[hector]

At crush you don't need to match ph to so2 addition .
That's why a 50ppm addition is standard .

This will inhibit native fauna but allow your innoculants to proceed.

Thanks for the info .

It's also recommended in the MoreWine's manual to add 50 ppm of SO2 after the crush based on the total volume of the must .

Does this total volume mean ( juice + skins + seeds ) or only the juice ?

I also read about the MLF and found it interesting , but VP31 and VP41 are very expensive ( 37.50$ at amazon only for 2.5 grams ! ) .

Hector

 

[sdelli]

It goes by total must after crush.... Usually net around 10% of gross grapes to must... 7% of gross grapes to juice.
Here is what was given to me to refer to on calculating this addition.....

KMETA ADDITION TO MUST

Grams of K-Meta = [(ppm needed) X (1.75) X (Gallons of Wine) X (3.785) ] / 1000
example; lets say you want to add 20ppm to 10 gallons of must..
(20 X 10 X 3.785 X 1.75 ) / 1000= 1.32 grams of Potassium Metabisulfite.. So this equation works only for Potassium Metabisulfite.. since it is only 57% effective.. that's where that 1.75 constant comes from in the equation.. 1.75 is the inverse of 0.57 or 57% I forget how effective sodium metabisulfite is.. if you were to use it the constant 1.75 would have to be adjusted..
so for your case its: (20ppm X 50gallons X 3.785 X 1.75) / 1000 = 6.62 grams (this is assuming 10 gallons of volume per 100 pounds of grapes..)
We calculate 3.3 grams for 10 gallons of must. For example, if we had 350 gallons of grapes, for our grapes, we calculate 27 gallons of must. The equation would be 3.3 grams x 2.7 = 8.91 g SO2. Stir into one cup of reserved must and add back to thentotal must.
http://www.brsquared.org/wine/Articles/SO2/SO2.htm

 

[hector]

so for your case its: (20ppm X 50gallons X 3.785 X 1.75) / 1000 = 6.62 grams (this is assuming 10 gallons of volume per 100 pounds of grapes..)
We calculate 3.3 grams for 10 gallons of must. For example, if we had 350 gallons of grapes, for our grapes, we calculate 27 gallons of must. The equation would be 3.3 grams x 2.7 = 8.91 g SO2. Stir into one cup of reserved must and add back to thentotal must.

Thanks for your explanation , but as I said before , I use 10% stock solution of K-Meta . I'd like to know if I should measure SO2 addition based on volume of the juice or volume of the juice and skins together .

Recently I made a small test batch . I crushed 9.2 lbs of grapes and it gave me 0.74 gallons of juice ( seperated from the skins and seeds ) . I did so , because I thought I can add SO2 more precisely that way .

Is it O.K. or should I measure the total volume ( juice and skins altogether ) and add SO2 based on that ?

P.S. If you're assuming that 100 lbs of grapes gives you 10 gallons of must , then why you calculate 27 gallons of must for 350 lbs of grapes ?!

Hector

 

[sdelli]

Thanks for your explanation , but as I said before , I use 10% stock solution of K-Meta . I'd like to know if I should measure SO2 addition based on volume of the juice or volume of the juice and skins together . Recently I made a small test batch . I crushed 9.2 lbs of grapes and it gave me 0.74 gallons of juice ( seperated from the skins and seeds ) . I did so , because I thought I can add SO2 more precisely that way . Is it O.K. or should I measure the total volume ( juice and skins altogether ) and add SO2 based on that ? P.S. If you're assuming that 100 lbs of grapes gives you 10 gallons of must , then why you calculate 27 gallons of must for 350 lbs of grapes ?! Hector

If you are trying to achieve the process of killing off any bacteria and wild yeast before creating your primary fermentation. Then you would use calculations to achieve 50 ppm on total must and juice to do this. Not just the juice.... You can do this with 10% stock solution calculations or dry as listed above.... I believe the example with 27 gallons was just to show the calculations thru..... After the crush you will know exactly how much must you have to calculate with.....