I was thinking of making two batches of beer in one day and using the same yeast. An extract bitter and an all grain IPA. I was thinking of making a 2qt starter with a white labs yeast vial the night before and splitting it between the two batches. Will there be enough yeast in the starter to do that?
Hell yeah! Do it.
Lots of good advice about making and using starters at mrmalty.com.
JZ’s Yeast Rate Calculater will estimate how of a starter you’ll need for each beer: Mrmalty.com