I'm experimenting with 1 gallon batches, and every single time I had a blowoff. So for the batch I brewed today I just put a bucket of sanitized water and a blowoff tube to start with since I know that it'll blowoff while I'm at work otherwise.
The recipe kit says to use half a pack of yeast, but even if I go below it I have Kräusen climbing out of the jug.
Is there any harm in this and having a blowoff tube for the first 24-30 hours? Is there any way to avoid blowoff completely without sacrificing the beer? (These 1 gallon batches are mainly for experimentation anyway, but they should still be good, drinkable beer)
I guess I could try to find 2 gallon jugs just so that I have plenty of headroom?