What constitutes a stuck fermentation?

[BFB]

I have a Belgian Dark Strong that I brewed a couple of weeks ago. The guy that gave me the recipe said to ferment at 64F for 2-3 days then raise the temp to 80F for the remainder of the primary. I am now at the end of the primary and the yeast has mostly dropped to the bottom. There is still some yeast in suspension. The OG was 1.108. The SG is 1.020. My target was 1.014. Is it stuck? Should I wait a little longer? Rouse the yeast by shaking gently? Add more yeast?

[tlael]

I have a Belgian Dark Strong that I brewed a couple of weeks ago. The guy that gave me the recipe said to ferment at 64F for 2-3 days then raise the temp to 80F for the remainder of the primary. I am now at the end of the primary and the yeast has mostly dropped to the bottom. There is still some yeast in suspension. The OG was 1.108. The SG is 1.020. My target was 1.014. Is it stuck? Should I wait a little longer? Rouse the yeast by shaking gently? Add more yeast?

Looking at your numbers, that's ~80% attenuation and 11.6% ABV.

What yeast strain did you use? For the majority of strains, it may just be done. Were there a lot of simple sugars? What was the mash temp?

Adding more yeast to a high alcohol environment may not do anything. Rousing may be the best option to get another point or two if there are fermentables left. I'd rouse it and let it sit another week or two.

Opinion 1 of 1,000,000.
Next.

BTW - 1.020 isn't terrible if you were expecting 1.014. 1.014 from a 1.108 is pretty damned ambitious. If you did hit 1.014, it'd be fairly thin and hot.

[brewinhard]

Depending on the yeast strain, health and pitch rate, along with aeration and fermentables in your grain bill, I would say that your fermentation is pretty much complete and not stuck. That was a very high starting gravity and I would bet that your strain of yeast reached its high end of attenuation. If you are concerned about it tasting too full than you could carbonate it a bit higher to add to the perceived dryness.

[Ozwald]

Depending on the yeast strain, health and pitch rate, along with aeration and fermentables in your grain bill, I would say that your fermentation is pretty much complete and not stuck. That was a very high starting gravity and I would bet that your strain of yeast reached its high end of attenuation. If you are concerned about it tasting too full than you could carbonate it a bit higher to add to the perceived dryness.

Get off yer tricycle and give some good advice... oh... you did. My bad. +1 then.

[ScottyB-Brewing]

I doubt it's stuck, if it was stuck it would probably have a much higher FG. Probably just done but I say give it some more time and keep checking.