Early MLF?
Scott Harring
I’ve had 3 wild batches underdo complete or near complete MLF in the first 2-3 weeks. Previously I’ve used pitched yeast and MLF didn’t happen or happened in the spring. I’m trying to figure out how do a decent wild ferment with my setup, and the early MLF has me puzzled.
pH batch 1: 3.63, TA 3.7
pH batch 2: 3.40, TA 5.8
pH batch 3: 3.39, TA 6.4
I initially fermented in 6.5 gal Fermonster carboys filled to 6 gallons or bit more. I fermented in temp controlled chest freezers set to 50-55F for these batches (10-13C). I tasted juice after a few weeks, it tasted much less acidic. MLF confirmed with chromatography and substantial TA drop. I also had MLF happen to the same batch 3 juice with Fermentis TF-6 yeast. This has been very slowly fermenting as well at 55F.
I don’t see a lot of mention of MLF happening early in fermentation to explain what happened here. I didn’t use sulfites for these batches.
These were desert apple blends which will probably now benefit from malic acid addition before botting. Is there an optimal time to do this and is there a good way to use sulfates to prevent second round of MLF? I fear these ciders will finish insipid if I don’t bring acidity back up and keep it there. Thanks,
Scott
Alexandra Beaulieu Boivin
That’s really interesting, Scott, those early MLFs make sense given your setup. Even though commercial LAB strains usually need 18–25 °C, some wild cellar strains can stay active at much cooler temps, especially if there’s no SO₂ and the yeast is slow to start.
If you’d like to delay MLF next time, you could try starting a small “pied-de-cuve” (a mini wild yeast starter) 6-7 days before pressing. That way, your alcoholic fermentation kicks off right away and has more chance to outcompete and delay the bacteria. A light dose of SO₂ or a bioprotective yeast at pressing can also help if you want to stay mostly natural.
If you plan to add malic acid later, definitely run a quick bench trial first, post-fermentation additions can sometimes taste quite sharp or candy-like. Remember that the CO2 from the carbonation will increase the acidity as well as its perception.
I hope this helps!
Alexandra
@alexandravinumartisan