Got an AG batch, OG 1.052, FG 1.01, Blonde ale, s-05, 5 oz cane sugar, 3 weeks at 70, 1 week in fridge. The beer tastes fine but when I first open a bottle, I get a slight gusher. I pour slowly in a clean glass and initially I get some head but within a minute or 2 it pretty much is gone and...