On to my sixth brew now and the head retention seems patchy. My first two brews I won't talk about. My third brew was excellent and had consistent head retention. My fourth, a whitebeer, was a bit of a flop with virtually no head. My fifth whilst nice tasting usually only produced a small head. I've only had two bottles so far from my sixth brew. The first one had a good head and tasted very nice, the second bottle had a disappointing head and maybe didn't taste as nice, or that could just be me. Before I brew my seventh this Friday are there any tips you recommend for getting better head retention? I use a Grainfather. I had thought I was under priming before bottling but for the last brew I was definitely at the top end of the priming sugar range.