Weird Fermentation Issue?

Hi Everyone, I've got my first batch of all grain beer in the fermentor right now and am not quite sure what's going on with this. This has always been my first place to run when I was worried or had questions before, but this is the first time I haven't found a thread the seems to cover my problem!

It's a simple ESB recipe, 1 gallon BIAB method. I had trouble holding a consistent temperature during the mash, and ended up taking the kettle on and off heat for the duration as the temperature moved up and down past the 153 degrees I was shooting for. Then it didn't seem to be able to manage more than a weak boil with the occasional rolling break (I blame the stove's electric elements for this one). I managed to get close to my target OG at 1.057 I finally got it down to pitch temp, shook the hell out of the carboy and pitched liquid 1968 London ESB. I didn't make a starter because I'd read it's not really necessary for this small of a batch. I've kept it in an ice chest holding at around 66-67

24 hours after pitch I saw an thin layer of krausen with some minor bubbling on the surface and no airlock activity. I figured all was well and fermentation was getting ramped up. Now it's 48 hours, and the krausen has pretty much totally fallen away. I never saw any of the swirling clumps of yeast I'm used to from this strain either. Any ideas what may be going on here?

Don't worry. fermenation is probably done. Small batch, big pitch. Not a lot for the yeast to eat so they are done.

Let it sit for a week or two and check the gravity. You are good.

You actually put double the amount of yeast than required for a batch that size so it's more like a big starter so i would check the gravity over a couple of days and see if it changes because the airlock doesn't allways indicate active fermentation

Oh, good. Thanks! I was wondering if it might have something to do with the small batch, I didn't even think about the amount of yeast I was pitching. :v

I guess my only question now would be if this will have any effect on how long I should leave it to ferment. My initial plan was to just leave it in primary for 3 weeks and bottle, is this not necessary in this case, or should I bottle sooner? Or does it even matter one way or another?

You are fine bottling 10-14 days after you pitched the yeast. Just make sure the 2 gravity readings over a couple day period are the same. There is no harm waiting the 3 weeks to bottle though. Whatever is more convenient for you.