Last night I embarked on a fun adventure to create a 14-16% ABV beer (Dema Goddess Ale), and it calls for aeration via an air pump that you would typically use in an aquarium. Due to the high concentration of sugar (a collective pound of demerara and cane sugar), as well as 13+ lbs of LME, it quickly produced an overwhelming amount of head that, unless looked after for the entire duration, would overflow creating a mess. Are there any ways to reduce the amount of foam that comes off the top of the wort when aerating with an aquarium pump?
I would recommend using an anti-foam agent such as fermcap-s http://www.northernbrewer.com/brewing/fermcap-s-1-oz.html or if your LHBS carries another anti foam agent. I have used these with great success in the past to prevent boil overs and also cut down on the mess associated with fermentations that require a blow-off tube.