Can you get a great beer if your mash is at 166F? Here is proof that you can however your beer is going to be different.
The Brewers Window is shown to the right at being from 147F to 158F. This would suggest that mashing over 158F gives you less fermentables sugars and going over 166F would give Even less. With 12 lbs of base malt I was able to get 2.4% ABV.
So why did I risk fermenting such a high mash temperature in the first place? My thermometer was not calibrated. I discovered after the mash that I was off by 11 degrees F. So my 155F mash was actually 166F.
Original gravity was 1.053 which is low for 12 lbs of base malt. Most of the sugars here are non-fermentable. My beers (yes I did this a few times) resulted in smooth malty drink that I and my friends enjoyed. The changes in the beer also resulted in low ABV. Final gravity was 1.031. Color was slightly darker. The biggest down side of these high temperature mashes are that beers are very filling. Having more that two in one night is a challenge.
Two lessons learned here. 1) Calibrate your thermometer frequently. 2) High mash temperatures on flavour grains delivers very nice smooth malty flavours.
I will consider doing separate mashes where I separate my base and flavour grain. (160F ish) from my flavour grains (150F ish) when I mash the base. I believe this will deliver better malty smooth beers while still delivering the ABV you expect.
IIPA Rahr 2-Row- July 20, 2012
Rahr 2-Row 12 lbs
Carapils ½ lbs
Crystal 40L ½ lbs
Magnum 2 oz
Simcoe 2 oz
Columbus 2 oz
Willimette 2 oz
Minutes left Gals Temp (F)
65 5 158
25 3.5 161
15 2 166
This produced 9 gals of wort
90 min boil
Minute left Adjunct
15 Simcoe, tablet, coil
Yeast Whitelabs 001
OG 1.053 or 13.2 Brix, FG 1.031 or 10.9 Brix, ABV 2.4%
Initial impression. I could let this age for a month and I think it would be a great bitter. This fermented for two weeks in the fridge at 68F.
Aug 4th - Kegged
Aug 12th Tasted this from the keg - plenty of body but still easy to drink. Nice aroma but not strong. Typical of a good FO hops. Very nice and worth doing again.
Sept 7 - All round good ale. Does not have a strong hops aroma nor does the little aroma smell that impressive. Actually a bit grassy. However the ale is smooth and nice to drink. The hops flavour comes through very well.
Sept 18 - This is one of the best IPA ales I’ve ever made. Beautiful malt flavour. Hops has a nice bitterness and nice hop flavour. Very little aroma. Make this again. Again got rid of the grassiness.
It was discovered later that the mash temperature was at 166F rather than 155F based on the calibration issue.