Malolactic Culture and Sulfites

[Resonant11]

Hello all,

I'm making my first wine from grapes this season, and I've run into my first issue. I added K-Meta at crush and cold-soaked for 2 days. I'm realizing belatedly that the sulfites will interfere with malolactic fermentation. Does it make sense to add the culture even if there are sulfites in the wine? I also have an extra vial of the culture, so I'm considering adding 1 during primary fermentation and the other later in the process. The grapes are Sabrevois.

Does my MLF have a chance? Any guidance on how to proceed?

Thanks!

 

[distancerunner]

Depends. (So many answers in winemaking start with that word.) How heavy was the initial dose?

It is customary to add 25 ppm (.025g/L) at the crush. The idea is kill off native yeasts to prevent spontaneous fermentation.

Above 50 ppm the sulfite will inhibit MLF.

 

[Resonant11]

I added approximately 50ppm, so probably a bit overkill. I don't have a way to test for that either, unfortunately. My hope is that the sulfite levels will fade enough to allow for MLF.

 

[Flufnagel]

Between the O2 exposure during cap punch-down, pressing, then racking off gross lees a day later, your free sulfite level after primary should be in fine shape for MLF.

 

[distancerunner]

They will drop.

Have you pitched yeast?

 

[Resonant11]

Thank you both for responding. I pitched the yeast yesterday evening, and it's slowly getting rolling.

 

[Jim Welch]

I’m interested in this subject too and have been wondering if it is only free sulphite that inhibits MLF.

 

[cmason1957]

I’m interested in this subject too and have been wondering if it is only free sulphite that inhibits MLF.

No it isn't just free sulphite that inhibits MLF, the total amount can cause issues as well.

Hello all,

I also have an extra vial of the culture, so I'm considering adding 1 during primary fermentation and the other later in the process. The grapes are Sabrevois.

Does my MLF have a chance? Any guidance on how to proceed?

Thanks!

When you say that you have an extra vial of MLF cultures, I really worry about sulphite levels. This is from memory, so I take it with that whole salt shaker. The last time I looked at the vials of MLF, the allowable sulfite level was very, very, very low, like 10 or 15 PPM. You may want to visit the manufacturers web site and verify that.

 

[Rice_Guy]

free SO2 breaks down quickly, you have the variable of time ,,, co-innoculating now doesn't sound good but waiting till 1.010 does

 

[mainshipfred]

I believe Craig is correct in that liquid cultures have a very low tolerance for SO2 and it is total and not just free sulfites. I believe if you were using a quality dry culture you would be just fine but the liquid I have my doubts.

 

[CDrew]

There is a lot of variability in SO2 tolerance of MLB. I think CH16 and VP41 are both tolerant to 40ppm or more. The others I'm not sure of but are likely lower.

As to your initial SO2 addition, this is likely not a problem because virtually all of it gets bound in the initial process. And I think if you have good fresh grapes, the initial SO2 addition is optional. Most wine making yeasts are extremely vigorous and will start fermentaion in 24 hours, decreasing the need for initial sulfite.

If you are worried, I like @Rice_Guy 's idea. Just let it ferment most of the way dry and then add your bacterial culture. The amount of free sulfite by then will likely be minimal.

What MLB culture are you using? You mentioned "vials" and there isn't a lot of reported success with liquid MLB cultures. So if yours does not seem to go well, you might use one of the known, reliable standards like CH16. It comes as a freeze dried packet and can go directly from the freezer into your wine. I've never had it fail.

 

[Resonant11]

There is a lot of variability in SO2 tolerance of MLB. I think CH16 and VP41 are both tolerant to 40ppm or more. The others I'm not sure of but are likely lower.

As to your initial SO2 addition, this is likely not a problem because virtually all of it gets bound in the initial process. And I think if you have good fresh grapes, the initial SO2 addition is optional. Most wine making yeasts are extremely vigorous and will start fermentaion in 24 hours, decreasing the need for initial sulfite.

If you are worried, I like @Rice_Guy 's idea. Just let it ferment most of the way dry and then add your bacterial culture. The amount of free sulfite by then will likely be minimal.

What MLB culture are you using? You mentioned "vials" and there isn't a lot of reported success with liquid MLB cultures. So if yours does not seem to go well, you might use one of the known, reliable standards like CH16. It comes as a freeze dried packet and can go directly from the freezer into your wine. I've never had it fail.

I've got White Labs WLP675 (Malo-Lactic Culture: White Labs 675). I should have done more research on the effectiveness of the specific type of MLB. I assumed they would all be of similar quality. Hopefully I can get the better stuff before I need it.

 

[mainshipfred]

I've got White Labs WLP675 (Malo-Lactic Culture: White Labs 675). I should have done more research on the effectiveness of the specific type of MLB. I assumed they would all be of similar quality. Hopefully I can get the better stuff before I need it.

I'm going to guess got it because it says it's for 6 gallons and substantially cheaper then the dry. The WLP675 from memory has a tolerance of 10 ppm and has to be added at the 5 brix mark. I'm not sure why White Labs insists on selling this product. Maybe their marketing makes it worth it.

 

[wineview]

Last year I had such a difficult time with MLF that I’m taking a break from it. I inoculated three different six gallon carboys with WLP 675 twice. Chromatography still showed it wasn’t finished. I used an entire package of CH 35 for the three carboys more than enough bacteria and nutrients. Kept the wine at 70-72* for five months. Chromatography still showed malic in the two Barolo carboys. The Zinfandel was complete. After tasting the Zinfandel, I didn’t notice any difference from any other wine that I have made without MLF. It was a very frustrating experience to say the least. I finally decided to add k-meta to the Barolo which is still in bulk and I’m planning to leave it there for another year. Not sure if that will change anything.

 

[Hazelemere]

I’m interested in this subject too and have been wondering if it is only free sulphite that inhibits MLF.

Absolutely correct answer FREE PLUS TOTAL MATTERS

 

[Nebbiolo020]

Generally speaking as long as sulfite level is below 50 ppm you will usually be able to start malolactic fermentation a lot of cultures are pretty tolerant these days. Laffort B7 direct is up to 60ppm I’ve had it finish in a wine with up to 75ppm myself because of a mistake