Nut Brown Extract: Slurry has sour smell

So, 3 weeks ago I brewed up our host’s nut brown ale and tonight I bottled directly from primary. FG sample smelled and tasted like a nut brown ale, but when I dumped the slurry out of the carboy, I noticed a rather sour smell. It was somewhat reminiscent of the flavor of sourdough bread, although it could probably also be described as just intensely yeasty.

Is this normal for nottingham ale yeast and/or the nut brown style, or is it possible the beer is infected? There were no signs of infection in the beer before I racked to the bottling bucket, just a nice, dark beer with a clean, smooth surface.

I love nut brown ales, and was really excited when I sampled it, but the smell has me worried I’ll be disappointed in a couple weeks…

you are probably fine. Once you rack off the beer, the primary fermenter is left with a lot of yeast in it and that will smell pretty… yeasty.

I’ve started paying attention to that yeast smell to get an idea of the differences between the yeasts. It becomes easier to taste the yeast contributions in beer when you can smell the yeast alone. The Cali Common yeast had a pretty distinct smell, as did the Kolsch that I just brewed.

In a couple of weeks you’ll be ready to crack one open. If there is a lot of yeastiness that will age out quickly in the bottles, so don’t toss the batch after the first tasting if you don’t love it. I think I had a similar issue with the Caribou Slobber kit where the first tasting wasn’t that great, but after another month in the bottle the flavors melded and it was fantastic.

Yeah, I’m used to the yeasty smell, this was just more unpleasant than usual. Upon smelling it, I did realize that I could taste a similar characteristic in the beer sample, and that never tasted off to me, it just tasted like nut brown ale.

I suppose what I’m really wondering is, is it possible to have an infection that doesn’t include growths in the carboy?