can there be a second krausen?

I brewed a porter exactly a month ago on wendsday. I popped off the airlock and looked through the whole because I was getting ready to bottle that night. When I looked in I seen what looked like a thin layer of krausen. Since I was going to bottle that night I figured I would pop the top off just a little bit and peer in. I was correct. Definetly looks like a thin layer of krausen.

I never left a beer in primary for a month so I don't know if this is normal because I read a lot on these forums and I do read a lot of people saying that the yeast will clean up after themselves after fermentation is complete.

Would this sometimes form a krausen ??

Temperature changes (warming) can cause co2 to come out of suspension.

It can look like its fermenting.

It did get cooler in philadelphia for a few days and the fermenter is in my basement. I did take it out of my swamp cooler a while ago but it dropped from 90 degrees to like 70 degrees by nighttime two days ago. Then it went up drasticaly again.

I would not let it swing in temperature like that. I'm surprised your basement swings 20 degrees.

well 70-90 degrees is outside temperature. I just thought about it and I don't think outside temp can effect my basement temp that much...

^ any more info on this??

I'm really curious what this is. Hopefully it goes away over the weekend.

I would take a temp of the beer. Use a stick on thermometer or tape some bubble wrap or foam to the outside and slide a kitchen thermometer's probe between the insulation and the wall of the fermenter.

Yeast is funny. You might have a bit more fermentation going but the only way to know would be to take the gravity over a few days to see if its going down.

I will do that today. Thank you!

ok so that "second krausen" went away and now it looks like what everyone on here calls yeast rafts. Looks and smells amazing can't wait to bottle tonight! :fro: :rockin: