Freakishly high FG on Mild

[brewerTristan]

I've had a mild ale in the primary for about 11 days now. I just recently took a gravity reading and it's at 1.018! The OG was 1.042. This seems freakishly high to me. I used safale 04, mashed at 155, and fermented at 65F. Does anyone know what may have caused this? Should I pitch more yeast? Bottle? The beer actually tastes okay, but I'm disappointed with this result.

[Bryantsbrewery]

1.042 to 1.018 is 57% appearent attenuation. If you want it to go further, I would suggest rousing the yeast and raising the temp to say 70 deg F or so. It should drop just a bit more over the next week. Between the higher mash temp and the english yeast strain, I wouldn't expect too much. I am not sure what the attenuation will end at, but the english strains are not the best attenuaters. 60 to 70 would be normal from what I have seen.

I hope this helps and in the mean time, relax and have a home brew!

[BDawg]

S-04, Wyeast 1968, and White Labs WLP002 are all similarly high floc yeasts that exhibit this trait.
+1 on rousing and letting it go for a bit more time.

HTH-

[brewerTristan]

Good tips, thanks guys. What's the best way to rouse? Shake the carboy up? Put a spoon in there and stir? I don't want increase risk of oxidation.

[BDawg]

Just a gentle swirl should be enough. You don't need to over do it. Just enough to kick the yeast up. I usually just tilt the carboy a bit and move it in a circular motion. DON'T do that on concrete or a hard floor. Put a rug underneath so the pressure doesn't break the thing. There's a lot of weight in there when they are full.