How many grams of sulfite to this batch

[geek]

My friend has a 200 liter SS tank in which he has a blend going through MLF with VO41.
He has around 36 gallons or so. His very first MLF process. 70% cab, 30% Merlot.

He doesn't have an SO2 test kit yet and wants to know ballpark how much sulfite to add once MLF is done (soon).

If we use ~5gr per 6g that would equal to something like 30gr of kmeta.

What would be a good ppm for it and how many grams of kmeta that should be, is my number above within range?

 

[Runningwolf]

My friend has a 200 liter SS tank in which he has a blend going through MLF with VO41.
He has around 36 gallons or so. His very first MLF process. 70% cab, 30% Merlot.

He doesn't have an SO2 test kit yet and wants to know ballpark how much sulfite to add once MLF is done (soon).

If we use ~5gr per 6g that would equal to something like 30gr of kmeta.

What would be a good ppm for it and how many grams of kmeta that should be, is my number above within range?

OK Geek by now you know the protocol and you've provided us with nothing. I am assuming because it's your friends wine. But we have to know what the S02 level is right now and the ph to determine an amount of meta.

He has 36 gallons. Let's assume (yes you know what that means) his ph is 3.6 and S02 is 12ppm. He would only need 6.7gr of meta to increase his ppm to 40ppm.

 

[geek]

The reason I didn't mention ph is because he doesn't know. He's Portuguese and had followed his old school friends by not using anything not even yeast...but now he's venturing into making things better but he doesn't even have a ph meter yet.
That was the first I asked him and again he doesn't have any other numbers.

 

[Runningwolf]

I figured something like that. At this point all you can do is use a wag measurement. Something is better than nothing.

 

[geek]

But in general, a wine that just went through MLF shouldn't have much sulfite, if any, at all.

 

[geek]

I'm thinking like wine kits, they have you add a ~6gr packet of sulfite to a 6gal batch....so I figured do the math based on that.

 

[ibglowin]

Don't you have a pH meter Varis?

The packs of KMETA that come with kits are 4-5GM. You will need less if the pH is lower. More if the pH is higher. Don't add more than 5gms / 6 Gallons max.

 

[geek]

I do but we don't live close by..!!

 

[sdelli]

My friend has a 200 liter SS tank in which he has a blend going through MLF with VO41.
He has around 36 gallons or so. His very first MLF process. 70% cab, 30% Merlot.

He doesn't have an SO2 test kit yet and wants to know ballpark how much sulfite to add once MLF is done (soon).

If we use ~5gr per 6g that would equal to something like 30gr of kmeta.

What would be a good ppm for it and how many grams of kmeta that should be, is my number above within range?

I think you are good with using that amount.... Might want to talk them into sending you a sample in 60 to 90 days to get a real reading though....

 

[Runningwolf]

Keep in mind, time will fix a wine with a little too much meta and it can be fixed. Vinegar cannot be fixed. The good news is that your friend is listening to you and adding some this time! A friend you are!

 

[jsiddall]

I'm thinking like wine kits, they have you add a ~6gr packet of sulfite to a 6gal batch....so I figured do the math based on that.

6 gram/6 gal does seem like a lot. I typically shoot for 4. Any the kits I have done were in the high 3's to high 4's also. If you go with 5 g per 6 gal that should be plenty of protection for many months of bulk aging in glass. Add some more at bottling if it is going to bottle age for many years.

 

[geek]

Thanks.
This is a new guy I recently met when we were picking up our grapes at Maltose. He heard me talking about my process that I always use MLF for grapes and he sounded interested....long conversation and he bought VP41 (he had bought Wyeast 4007 following the feedback from the folks at the LHBS and I had him literally go back and exchange with VP41...

So again, all his Portuguese friends make wine the old fashioned way and I encouraged him to follow better practices by using the methods we use nowadays. His friends don't even use yeast for God's sake.... as they think mother nature will follow its course.

Anyhow, bottom line is that he is getting into purchasing some stuff he needs, he already bought the MLF test kit from PIWines and is bringing a wine sample to the place he works at because they have some sort of a lab in which he will let me know PH and hopefully SO2 level.

 

[GreginND]

If I don't have information on SO2 or pH I usually err on the side of using 0.4g per gallon. That is roughly equal to 1 campden tablet per gallon. This should be about 50 ppm SO2. So, for 36 gal use 14.4 g of potassium metabisulfite.

 

[JohnT]

Assuming that you hove no free SO2 currently in the wine,

Let's assume that you want to raise 50ppm,

17grams of k-meta should be enough (my math actually says 17.3561 grams)...