The last couple of Belgians I've brewed, a Chimay Red and a Strong Blonde Ale have been great beers but pour with a decent head that subsides fairly quickly. I used a 90 minute mash for these and I'm wondering if this is the culprit with the highly modified malts. I haven't had this happen with any other beers using a 60 minute mash and 10 minute mash out. I'm going with a shorter mash next time and will see what happens. Anyone else had this problem?