Infection during MLF

[From_LV]

My merlot got a sign of infection during MLF, so I racked and added sulfite. The MLF was only half way done when the infection occurred. I’m wondering if I can wait for sulfite to go down and restart MLF again. If not, can you advise in what to do as merlot is still pretty tart.

Thanks!

 

[Ike64]

If it was me, I'd rather have a tart wine, than a spoiled wine. If an infection started during MLF, then you might have elevated VA. You might get that tested along with acid forms and TA. I'd personally keep my SO2 levels up. If your acid is high, then you can use some calcium carbonate to reduce it. But this can strip color and reduce fruitiness. I'd also give it some time (month+) after this last racking and sulfite addition to see if things balance out any.

 

[NorCal]

I’d do the same as @Ike64 recommended, but would add that I would look to blend with higher pH and perhaps cold crash it to see if you can get some of the acid to fallout. Calcium carbonate would be my last choice and I would do trials / use only if it meant keeping vs tossing the wine