over attenuated?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bnmir

Well-Known Member
Joined
Jan 2, 2010
Messages
305
Reaction score
10
Location
Pittsburgh
So i brewed a brown ale last Saturday, OG 1.056, and pitched the slurry from a 1L starter of WLP 002. This was all grain, mashed at 153.
I pulled a sample last night, and its down to 1.011, which is a lot more attenuation than I expected from this yeast.
So i'll get a higher alcohol level and less residual sweetness, and its definitely lighter bodied than I was shooting for. What would cause this?
 
sometimes yeast are over performers... also, other things in your wort could help the yeast eat more... Things like pH etc could, but I'm not sure. Mashing slightly higher, increases the kinds of sugars that don't get digested, so you'd get less attenuation, etc. So if you mashed at, say 157 it may have stopped a bit earlier. There are TONS of variables in that mix, though, water could be one too. Yeast are living things and don't always behave like a machine.
 
The first thing to check is the accuracy of your thermometer. Just because it says 153 doesn't mean it is 153. And verifying it against boiling won't cut it. Thermometers are wrong by different amounts at different temperatures. The only feasible solution is to get a NIST traceable thermometer.

I found my thermometers were reading the temperature lower than the actual temperature. So, my final gravity was always higher than intended. You may have the opposite problem!
 
+1 to there being many reasons. I'd start with your thermometers first calibrate those and take it from there.
 
So you are saying that mash temp is probably the biggest factor?
Would fermentation temp have a large or small effect, relatively speaking?
How about pitch rate?
 
The mash temp is a big determining factor but it is a bit puzzling to me since 153' is not a particularly low mash temp. I agree with the others that you should check your thermometer. I use a Thermapen and it is spot on each time. The 1ltr starter is not particularly large either. Montanaandy
 
I always use two thermometers ever since i had a digital one go bad a few batches ago.
Yes, I did in fact use 1 lb of honey! I wasn't thinking about that being more fermentable than the wort. I'll post the recipe later.
 
8lbs UK 2 row
12oz crystal 40
8oz honey malt
6 oz special roast
4 oz biscuit
4 oz chocolate malt
1 oz goldings (60min)
.25oz fuggles, 10 min
whirlfloc tab
1 lb honey
OG 1.057, FG 1.010
60 min mash at 153, batch sparged,
7.25g boil, 6g into the primary
wlp002 english ale (slurry from a 1L stirplate starter)
 
mmm. That actually looks good. It's probably the honey that dried you out, but it is still possible that you mashed lower than you think.
 
Back
Top