Crazy Attentuation on IIPA

[TBC27]

I brewed an all grain IIPA last weekend (Dec 3 2016). Here is the recipe - https://www.northernbrewer.com/documentation/allgrain/AG-WestCoastImperialIPA.pdf. I missed my OG by quite a bit. My hydrometer read 1.078 prior to racking and recipe shoots for 1.086. I am not looking to discuss why I was low on my OG. Rather, I wanted to ask about the fermentation I experienced.

I pitched two packets of Wyeast American Ale II 1272 once my wort had cooled to 66F. Active fermentation started within 6-8 hours post pitch. As of last night (8 days after pitching), my hydrometer read 1.006! That makes the ABV 9.45% and is an apparent attentuation of 92%. Is that even possible? Should I be concerned? The fermentation did produce a rather sulfury smell during those 8 days.

 

[ScrewyBrewer]

My guess is that a combination of low mash temperature and a low mash pH is the reason for lower than anticipated attenuation. Either of the two will have an impact on the production of fermentable sugar by the beta amylase enzyme.

Ruling out any possibility of contamination of course.

 

[TBC27]

My guess is that a combination of low mash temperature and a low mash pH is the reason for lower than anticipated attenuation. Either of the two will have an impact on the production of fermentable sugar by the beta amylase enzyme.

Ruling out any possibility of contamination of course.

My attenuation was high though (92%)...

 

[Redlantern]

Calibrated hydrometer?

Just asking because if you take the difference between target OG and actual, the difference is .008.

Add that to the FG and you get a 1.016 FG, which would match pretty well with that strain.

Not commenting on whether or not it is or is not possible with 1272, just curious that it happened so fast.....

 

[TBC27]

Calibrated hydrometer?

Just asking because if you take the difference between target OG and actual, the difference is .008.

Add that to the FG and you get a 1.016 FG, which would match pretty well with that strain.

Not commenting on whether or not it is or is not possible with 1272, just curious that it happened so fast.....

I did check my hydrometer's calibration and it is a tad off. In 68F tap water it read 1.004 rather than an expected 1.000. IMO though that shouldn't matter because all of my readings are off by .004 including my FG, right? With that logic in mind, that would mean my OG was really 1.082 (1.078 + 0.004) and my FG was really 1.010 (1.006 + .004). Plugging in those numbers new numbers into an ABV calc does drop the attentuation from 92% to 87%, but it is still far above what is expected for that strain of yeast.

 

[orionol73]

I have been using the same yeast in a bunch of pale ales and IPA's lately and have also been experiencing high attenuation. The first batch I made with it finished at 1.005! I thought I was crazy so I was re-testing everything and double checking all of my numbers and everything else. As I have continued to use it, I have consistently had FG between 1.010 and 1.005 from all range of OG's. Its very like a result of a process in my brewing but with my set-up it just seems to be a beast of yeast. The best part is even with such low FG the beers are not overly dry.

 

[rmhays25]

If it read 1.004 against the 1.000 of tap water, that would mean you need to subtract .004 to get to your "adjusted" results, wouldn't it? So 1.074 and 1.002??

 

[Redlantern]

I did check my hydrometer's calibration and it is a tad off. In 68F tap water it read 1.004 rather than an expected 1.000. IMO though that shouldn't matter because all of my readings are off by .004 including my FG, right? With that logic in mind, that would mean my OG was really 1.082 (1.078 + 0.004) and my FG was really 1.010 (1.006 + .004). Plugging in those numbers new numbers into an ABV calc does drop the attentuation from 92% to 87%, but it is still far above what is expected for that strain of yeast.

Can't read it in tap water. has to be distilled.

 

[TBC27]

If it read 1.004 against the 1.000 of tap water, that would mean you need to subtract .004 to get to your "adjusted" results, wouldn't it? So 1.074 and 1.002??

Touche! Those numbers turn my apparent attentuation to 97%. Sheesh! That just doesn't seem realistic to me...

 

[TBC27]

Can't read it in tap water. has to be distilled.

Good point. I will re-calibrate tonight. Will spring water suffice? I don't have any distilled water.

 

[Redlantern]

Tap water, spring water, drinking water all has mineral additions that will affect the reading. Maybe not much sometimes, but it will still throw the reading off.

Has to be distilled water.

Good news is that you can get it at most any grocery store right next to the spring water - and it is only a buck a gallon or so.

 

[TBC27]

Tap water, spring water, drinking water all has mineral additions that will affect the reading. Maybe not much sometimes, but it will still throw the reading off.

Has to be distilled water.

Good news is that you can get it at most any grocery store right next to the spring water - and it is only a buck a gallon or so.

That's pretty steep! Can I borrow a buck? bwahahaha :rockin: