I have a 2L flask that I make my starters out of. I've made quite a few 1.5L and even one other 2L in that. Never with a problem. Well I did a 2L with WLP001 and the krausen was intense. I kept a good eye on it to ensure the foil didn't come off and it get contaminated. But just wondering, when there is a Krausen overflow, is there a loss of yeast, or is that just excess?
Lesson learned... use bigger flask for 2L.
Imperial Stout from Northern Brewer
Bud Light Clone
Munich Helles Lager