> I am confused. I thought MLT was malolactic fermentation and I thought
> took place in ageing, long after racking off the lees.
Spontaneous ML tends to occur later in a wine's development. Modern
winemaking technique is inoculation with a cultured strain, often right at
the beginning of the sugar (yeast) fermentation so they run concurrently.
And don't you
> normally sulfite the must right after you crush to kill off the wild
Yes, but the gassing of the fermentation blows off most of the SO2, so the
ML goes pretty much unimpeded, if delayed a little. A lot of winemakers add
no SO2 at crush if the grapes look clean and healthy so's to help the ML
> And is it necessary to add a malolactic starter and starter food?
Not necessary, but advisable. Spontaneous bacterial fermentations can
sometimes produce some unpleasant flavors, aromas and excessive levels of VA
(volatile acidity). Same goes for yeast. It's cheap insurance.