Should I add oxygen to my poorly attenuating Imperial Stout?

[rrayriver]

The OG of my Imperial Stout was 1.088. After eight days I am at 1.026. Should I add some oxygen using a stone or rouse the yeast to get it down further? I am aiming at 1.014-using WLP001. (Since I am using a 14 gallon fermenter, its not as easy to rouse as a six gallon carboy).

 

[norsk]

Lots of variables. Grain bill, mash temp, additions, amount of yeast pitched, etc. etc. Whatever you do, don't add O2 at this point. You could rouse it a bit, maybe move it to a warmer location, perhaps even add more yeast. The good thing is that you have beer right now. 8 days is pretty soon for most people, though most of my beers are done by then. Depending on how you answer the variables, I'd probably rouse the yeast a bit and park it somewhere in the mid 70s for a week or so. Good luck. As it is now, you have an 8% beer with close to 70% attenuation. Not bad....

 

[TungstenBeer]

Agree with the guy above me. Definitely do not add O2 at this point. Rouse it if you can though.

Are you sure 1.014 is the correct target FG? Seems a little low for an imperial stout.

Extract or all grain?

 

[Kaz]

1.088 to 1.026 in 8 days is pretty good. Also, 8 days is not very long to be checking for final gravity. I would give it another 2 weeks, check again and if it hasn't gone down at that point, move it to somewhere warmer. Was this an extract recipe, they will finish a little higher. Also, a IS usually will finish in the high teens or low 20's, if it goes too low, it may seem thin or watery. I like my Imperial Stouts a little chewy.

 

[BigFloyd]

You're at 70% after just 8 days on an RIS. That ain't bad, but a big beer like that needs more time. How much yeast did you pitch?

The LAST thing you want to do at this stage is add O2. The yeast have been in anaerobic fermentation for a while now. Adding O2 will mess that up and also cause this beer to get stale early.

With a 1.088 RIS, you don't really expect (or want) to go to 1.014, do you?. That's 84% attenuation which is above the range (73-80%) for that yeast.

 

[rrayriver]

All very good information. Here are the answers to the questions posed:
It was a 10 gallon AG recipe -I started from a Yeti clone and made some modifications
I pitched the recommended 2-2 liter starters (10 gallon batch) for a total of about 600-650 million cells.
I guess I was over estimating my attenuation goal. I will swirl and rouse a bit and bump up my temp to 74 and let it ride for another couple weeks. Thanks for all the advice!