Over Attenuated brews

Lately my brews seem to be a little over attenuated. Last weekend I brewed a strong brown ale using Wyeast 1968 and it went from 1.083 to 1.014 in under a week. Fearing it might end up a little sweet I did use a pound of brown sugar, but that shouldn’t be the cause. I did my usual mash at 150* and ferment at 65*, so what gives?

The last time I had a few brews in a row that seemed just a bit under attenuated,
I finally checked my thermometer and found it reading 5* low.
1.014 doesn’t sound overly dry for a brown ale.

I think it is the brown sugar that did it. I agree that checking calibration of your thermometer is definitely a good idea.

Thats very high attenuation for that strain. I know of a brewery that uses that one as their house strain and 77-78% is what they max it out as.

I’m assuming if there was infection you would have picked up on that…so I’m going with what the others have said too mash temp. IMO 150F would be low anyway for what I;m assuming is a strong English Brown. So even if the temp was correct its probably more fermentable than you would want it to be. 154-55 would be a bit better.

Have you changed maltsters? Are your last few recipes including less crystal malts?

Without the sugar, you’re talking about going from 1.075 to 1.017, which sounds pretty normal.

The beer tastes clean and pretty good for being a strong ale only a week old. I guess I was just looking for something a little maltier.

I definitely think the sugar addition had something to do with it.

Interesting that you note the clean flavor for a strong beer that young. Give it a few weeks (or months if you can manage it) and it will be even better. I believe I read an article some time ago that mentions the fact that ales made with a moderate amount of sugar do indeed mature faster. I wish I had a copy of that article, since it went into a bit of the science behind that assertion.
In any case, as I’ve mentioned elsewhere, my Brit styled ales didn’t taste authentic until I started using some sugar in the boil. Along the way I’ve started mashing just a bit higher when I know that there will be sugar going in as well.

Sounds like you just need to mash a little higher. Maybe 154-155. But yes, definitely calibrate your thermometer.

You say you wanted it to be maltier, but it sounds like your complaint is that you wish there were more residual sugars. If you’re looking for more residual sugars with the same yeast, I’d mash higher and/or cut the simple sugar addition. If you’re looking for a maltier beer with the same yeast, you’re going to want to change the quality or composition of your malt bill, or try fermenting a bit lower. If this is a yeast you use a lot, I’d consider getting another pack of it, in case you got a bad culture to begin with.

Maybe hearing stories about how Wyeast 1968 is a low attenuater and will leave a bigger beer sweet, I felt the need to sub some sugar. I compared my two thermometers and they are reading 4 degrees different.