hey I just racked my first batch into a secondary fermenter, a 6.5 gallon carboy. THe volume of the batch ended up being about 4.75 gallons, and now i read that you want to minimize headspace. So, am i going to have a problem?
Or, better yet, brew a six gallon batch next time.
Edit: actually, though, c.n. budz is right; more traditional is a larger primary and smaller secondary. I have 6g primaries and 5g secondaries and brew 5.5 gallon batches. Tends to nicely fill up the six gallon to minimal head space and does the same when I rack to the secondary, leaving some of the beer behind with the trub.