There's a substance called (literally) anti-foam that may have caused this for me. Shouldn't have any problem with tomato sauce or beer. It's used in production processes to reduce foaming caused by the high flow rates through systems. Unfortunately, it is VERY difficult to clean out of these barrels, as it has great affinity to the plastic (hydrophobicity). The first barrel I used didn't have the substance I guess. Sorry about not pulling through, but I wouldn't feel right about giving out a barrel that could kill your skimmer.