As SG said, it's already got active LB culture in it. But, really not necessary. Just the yeasties and bacteria floating in your air will make a nice culture. You can also add a little splash of raw ACV, which will speed the process, but totally not necessary. One reader added a whole lot of ACV and her culture didn't grow. When reminded that the goal was not to pickle it, she diluted it down a whole lot, and then got her ferment going.Did I say butterscotch. Lol
I mean buttermilk. I think.
I had read it somewhere for the ff but can't remember why it was good for them.