S-05 SN Torpedo clone Under attenuated or reasonable

So, to dry hop my SN Torpedo IPA clone I opened the bucket and grabbed a gravity sample. This beer started at 1.086 and after two weeks is now at 1.028. This calculates to an apparent attenuation of 65.8%. I dropped in a 1/2 oz. each of Cascade and Nugget whole hops and will leave it for a couple more weeks.

This was my first all grain batch. I mashed at 154degF. and have fermented at 59-68 deg. F. I must say that my fermentation temp control strategy is to place my fermentor in the most stable part of my home but the temp does swing through the above range during the day (especially during the winter months).

I guess my question is that given the mash temp. and fermentation temp. control is that amount of attenuation reasonable? Will is see the gravity drop a bit more under those same conditions over next two weeks?

Should I really invest in some type of fermentation temp. control?

Thanks, Dave

You really should have seen better attenuation. You run a great risk of having fermentation resume in the bottle. You can wrap your bucket with an old blanket to help insulate against those big swings. Having dropped to 59 there is a good chance that a good portion of your yeast fell out of suspension. I think you would want to look into some form of fermentation temp control. In the future I recommend waiting until after you are sure fermentation is complete to dryhop. Additional fermentation will scrub some of the aroma you are trying to impart, plus you may have to wait an indefinite period of time for that fermentation to be complete. Dryhopping beyond 14 days begins to impart "grassy or vegetal" flavors which are not favorable.
Before you take any further steps to jump-start your yeast you should check the calibration of your thermometer. If it is off and you mashed higher than expected your beer may actually be done.

Yeah, I did calibrate my thermometer when I mashed. So I'm pretty confident that my mash temp. was actually 154 deg. F. Given I guess I'll move the fermentor to a warmer spot and swirl the bucket to rouse the yeast.

Thanks a bunch.

Best, Dave

What kind of yeast did you use? If you used a low attenuating yeast, it might be done. If you used a higher attenuating yeast, it sounds like you're stuck.

Yeast was Safale S-05 which, it certainly seems, should get me over 75% right?

How many gallons of beer are you fermenting? Are the temp readings the air temp or from your beer? The more beer, the less effect the air temp swings are going to have.

Hermit said:

How many gallons of beer are you fermenting? Are the temp readings the air temp or from your beer? The more beer, the less effect the air temp swings are going to have.

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This is a 4 Gallon batch. The temp readings are ambient air temp. in my 1/2 Bath/FermentationChamber/Man Reading Room upstairs in our home.

daveyohill said:

This is a 4 Gallon batch. The temp readings are ambient air temp. in my 1/2 Bath/FermentationChamber/Man Reading Room upstairs in our home.

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4 gallons liquid is not going to change temperature nearly as fast as the ambient.