So I'm still pretty fresh on the whole homebrewing circuit (got the go pro small batch kit for my birthday last year) and have only brewed 2 batches before, but I did 2 more this past weekend and noticed something a bit funny between the two.
Both are Bavarian Hefeweizen 1 Gal Extract kits, both made nearly the same way. The only thing different between the two is one was purchased a several months ago (Around october) rather than around Christmas (2nd was a gift from my parents). Both had the yeast pitched around 66-67 degrees and have been in a spare bedroom where the ambient temp is around 68 degrees (glass carboys, blanket wrapped around them to keep the kiddo from messing with them)
Within 12hrs they both were starting to bubble away, but now nearly 60hrs into it, I've noticed one isn't as vigorous as the other, and considerably lighter already. By that, I mean one has about an 1.5" of foam and the other is nearly .5". At first I figured it was due to the large amount of head space, but slowly I began to question it. I checked the lid, airlock, and bung and all seem to be in order no leaks.
Just curious as to what could cause something like this to happen between two nearly identical batches. Is it just chance? I'm not worried about it at all, just curious.