OK so I've got a wit from BCS in my fermenter. Its been in there two and a half weeks at around 68. I still have a small krausen on the top of the beer. Yesterday I took the water out of the tub and raised it up to room temp. Around 72. Still have the krausen. Should I wait for this to drop out or should I cold crash it and rack to my keg. Im almost certain Im at my FG. I havent taken a sample because I dont have a thief and my racking cane is a pain to sanitize.

serious top croppers can leave krausen that just stays forever

-what yeast did you use?
-did you make a starter?
-what was your fermenation temperature profile?

if you made an appropriate starter and "drove" the fermentation, it probably is done. if you didn't, i'd be very hesitant to assume FG without measuring.

Used a starter with WLP400. Had vigorous ferment within six hours. Pitched at 68 for two weeks, then ramped up to 72. I know this is a low flocculation yeast, but I wasn't sure if I should wait for it to drop out or just crash it.

hmm that sounds good, but personally, i'd still like to be sure. you put in the time on brewday and waited two weeks -- what's another hour or so to sanitize the racking cane and take a sample? that's just me though...

Yeah I get that but i guess my question is more about the krausen. If im at my fg should i cold crash or wait for it to naturally drop out?

I just made a Wit a few weeks back for Big Brew day, using the WLP400, and still had krausen after 3 weeks, I fermented at 66 if memory serves me right.

So, yes, there can be a small krausen on the top, after fermentation is finished, which you really won't KNOW for sure, until you take gravity readings.

Patience, my man, patience. Take some readins and if it is leveled out and stopped where you need it to be, rack that bastard and be done with it. If not, wait.

I have had the same thing happen with WLP320? American Hefe Yeast. It looks like Krausen, but it's probably just yeast rafts. I suggest checking your gravity and that will really tell you what's going on. My bet is that it's probably done.