I made a blueberry cream ale a while back using blueberry extract from my LHBS. I used the amount of priming sugar that was recommended in the kit directions (4oz) for a 5 gal. batch and cracked one open the other day after almost 3 weeks in bottles. Poured one in a glass and there was about a half inch of actual beer and the rest foam. Had a couple other people do it to and same results. Any idea why this might be?? It's like someone shook them all up and tried pouring them.