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Stuck fermentation?

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mximus11

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Ok so here's the deal. I brewed up a batch of beer about two and a half weeks ago. Fermentation was going great, then it kinda came to a stand still. The beer was a christmas ale, I know I'm running behind! Starting gravity was 1.065, and it has stopped at 1.018. The yeast I used was Fermentis Safbrew S 33. I'm thinking that I may not have aerated the wort enough. I did move the carboy to a slightly warmer spot so its sitting at about 68° right now. Should I get another pack of yeast and pitch it? Please help!
 

FensterBos

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I think my math is wrong, but isn't that 73% attenuation? If so, I think that is about right.
If not, there is still a good chance that you just have a medium to full-bodied beer. Did you all-grain or extract brew?
 
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mximus11

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This was an all grain batch. I guess I was thinking it was too high for a final gravity reading. Still fairly new to brewing and I don't quite have all the science down. Do you think I'm good at 1.018 as a final gravity?
 
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1.018 is an acceptable FG for many styles that have some body and residual sugar in them, like bocks and IPAs. Whether you're happy with it, however, will depend on what you were going for and what your taste preference is.

With that said, stuck fermentations are actually pretty rare. You are already at 73% attenuation, which is about normal as FensterBos said. My guess is that your brew is done.

You haven't said what temperature you mashed at. Mashing too hot could be the cause if your brew didn't ferment as much as you expected. Temperatures near the higher end of the usual range (e.g., 154-155°F) will produce a less fermentable, fuller bodied wort. If you're not happy with the way this beer turns out and want it drier next time you make this recipe, lower your mash temperature a few degrees on the next batch. This makes a huge difference when all-grain brewing.
 
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mximus11

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Sorry for lacking on details. I did mash at 155°. If you fellas think that I'm good at the gravity I'm at then I will take your word got it. I do like malty beers do this could be a treat! Thanks for the quick help everyone!
 

FensterBos

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I think you're good; I've had a few brews I thought were going to be a lot lower, but my mash temperatures were WAY too high and I converted a lot more unfermentable sugars and body than I was expecting.
This brew will have more body and will probably be maltier.
 
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