WLP002 resulting in too much banana smell?

[Indyking]

Brewed an English brown this past weekend. Everything went well, only my efficiency came out really high and the volume a bit shorter from 5 gal, resulting in a higher-than-planned OG of 1.060.

I knew WLP002 can result in a lot of ester production at higher temps, characterized mainly by a banana or apple smell.

Having said that, I had 2 options as far fermentation temps in my house: 1-keep it at around 66-68, which is in the range recommended by WLP, or 2-put it in the basement at 57-59F, which I thought was going to be too could.

Went for option 1! After cooling the wort down to around 70F, its temp (measured by strip thermometer in the fermenter) a few hours after pitching (8-12h) escalated to 74F! As a result, the resulting banana smell coming out from a crazily bubbling airlock was so strong that I think the monkeys all the way down to the rainforest in Central America could smell it

24h after pitching I decided to move the fermenter to option 2, in the basement, i.e. at 57-59F. It seems like the wort is now (2 days after pitching) stable at 60-61F according to the strip thermometer, so the strong banana smell is gone, but bubbling in the airlock is going on awfully slow, once every 40-50 seconds or so!!!

I'm afraid the low temps now are throwing the yeast into dormancy but don't want move it back to 66-68F and ruin the beer with esters!

What would you do?

 

[brew2enjoy]

I just pitched WLP002 in my IPA on Saturday. By Sunday morning I had the most active fermentation I have ever seen. Only problem is it caused the temps to rise more then I anticipated. I think it maxed out at 72 so I think I will be ok, but it went from 63 in the morning to 72 over the course of the day. It is stable at 67 now.

My noob opinion is that your most active fermentation is over, so you can probably move it out of the basement now.

 

[Toga]

I would bring it back upstairs and strap a freezer pack or two to it with an ace bandage to keep the temps down. Swap them out every 12 hours or as necessary.

 

[Indyking]

Thanks for the help so far folks. I just researched WLP002 a bit more and found out that it is not unusual for this yeast do most of its attenuation in the first 48 hours after pitching, especially at higher temps like I used for my first 24 hours. I just thought it was amazing that despite of my room temp being 66-68F, the wort kept at 74F all the time when airlock activity was crazy. Very robust exothermic yeast indeed!

So it seems like that, perhaps, the lower activity of the airlock and fading of the banana smell I’m seen now is just because the yeast is almost done! I also found out its attenuation may not be as good as advertised. Although the manufacturer states attenuation of 63-70%, people in other forums were often in the lower end of that range and sometimes even lower, with just 60-61% attenuation. Bummer!