Following up, the dampfbier made in an open fermentor (a bucket with the lid on loosely) came out wonderful! It's clovey, limited esters, kind of like an Erdinger without the wheat. I'll do this experiment again with another beer, maybe the next five-gallon batch I brew. I like the notion of having access to the beer without using the spigot or a thief through a carboy's bung. I was afraid of contamination - someone had knocked the bucket lid partially off and I didn't discover it for at least a day, still no problem. So my first experience with "open" fermentation - not bad, particularly if it's a yeast I want to harvest.