First dose sulfite in wine getting MLF

Stressbaby · Sep 23, 2016

I'm reading conflicting things on the first dose of sulfite in wines for which MLF is planned. I see some information which says don't sulfite at all until after MLF. I see other information which says 50ppm at crush, which will dissipate enough during primary fermentation (ie, to <10 free SO4) to add MLF at the end, then a full dose after MLF complete.

Can someone clarify this for me? Thanks in advance.

Johnd · Sep 23, 2016

Stressbaby said:
I'm reading conflicting things on the first dose of sulfite in wines for which MLF is planned. I see some information which says don't sulfite at all until after MLF. I see other information which says 50ppm at crush, which will dissipate enough during primary fermentation (ie, to <10 free SO4) to add MLF at the end, then a full dose after MLF complete.

Can someone clarify this for me? Thanks in advance.

Many sulfite at crush to inhibit wild organisms prior to pitching their desired yeast, this is OK if you intend to MLF after or near the end of fermentation.

No sulfite is also OK also, if you feel like taking the chance. Personally, I don't think it's a big deal and don't sulfite before pitching yeast, but that's my choice.

JohnT · Sep 27, 2016

I use CH16 MLB. This strain has a high SO2 tolerance and can easily thrive in wines where you have added up to 70ppm prior to alcoholic fermentation. It also survives in wine that is at 16% abv and lower.

With that in mind, I do add k-meta at crush. I wait a day, then pitch my yeast. I want to stun any pre-existing yeast or bacteria and allow my cultured strain of yeast a more clearer shot at dominance.

So I add 50ppm (well below what is recommended). As you have said, the SO2 levels will drop as a result of alcoholic fermentation and a day of "wait time" also further reduces the SO2 levels. I have never had a problem with MLF.

Stressbaby · Sep 28, 2016

Thanks for the replies - reassuring

MisterEd · Sep 29, 2016

Is this a red or white? I'm with those who avoid sulfites til after primary ferment & MLF. But I also pitch my yeast very quickly after crush on reds. A low dose of SO2 on a chardonel after crush and before press is OK since it may sit over nite before being pressed. Everyone's mileage may vary. I prefer to avoid SO2 if I want to give MLF bacteria there best shot at doing their intended job.