Bubbles in airlock after adding hops

[WiscoMan]

I toss in 1 oz of hops the other day into my primary fermenting carboy. My beer has been in the carboy for a little over 3 weeks now. I checked on the beer the next day and saw activity in the airlock(which had previously stopped). Here are the before adding the hops and after pictures of my carboy.

It almost looks as if fermentation has begun again a little bit. Right now the room I have the carboy in is cold, 40-50s. Should I bring the temp back up??

 

[duboman]

The addition of hops created more nuclear ion sites for the suspended co2 and created additional off gassing, unless you see another formation of Krausen that's all it is
Edit: just noticed the pics, did you verify that the beer was done fermenting? That looks like more krausen and it wasn't done.....

You shouldn't dry hop until the beer drops bright and clears and reaches final gravity

 

[WiscoMan]

I figured that it was done fermenting since it had been going for 3 weeks and I wasn't seeing any airlock activity.

However, I did have my room cold for fermentation (high 50s, low 60s). Maybe my yeast went dorment and now are starting up again?

Should I bring the temperature back up?

 

[BigFloyd]

If you pitched sufficient yeast and kept the ferment in the proper range with no big fluctuations, it ought to have completely finished by three weeks. Also, it would be most unlikely for an ale yeast to kick back up and start fermenting again in the 40-50* range.

It's hard for me to tell from the pics since it looks like quite a bit of hops added. They can cause some off-gassing even if it was done.

Depending on the strain, however, it may have dropped out if it got down below 60. Get a grav reading before taking any action.

 

[TipsyDragon]

An airlock is NOT a fermentation indicator it is a pressure release valve only. A bubbling air lock does not equal fermentation. The hops probably provided nucleation sites for residual CO2 formation.