A pack of yeast is good for 7 gallons. If I have 3 one gallon batches starting,
can I split one pack a yeast into 1/3? Why use a whole pack of yeast per one gallon of juice?
Because the package of yeast is only around a buck...
I have split a package before when I was doing 2 gallons of wine and fermenting in 1 gallon jugs, but in any other scenario I would use the whole package of yeast.
I'd split it like you're thinking about. True dry yeast is cheap, but why spend 3 bucks when one buck will do. Plus if you pitch a whole pack in each gallon, you're likely overpitching,.