Stuck F.G. is way to high...

I made a Belgian quad and I think I mashed too high at 158-160. My OG was 1.081 and it is stuck at 1.031. I contacted my LHBS and they said I had a stuck fermentation. Told me to try pitching more yeast, try the t-58 I had on hand and if that did not work to pick up champagne yeast. I added the t-58 waited three days and nothing, then added the champagne yeast and nothing. I am warming it up because it was in the low 60's but I am lost other wise. Any help or suggestions.... ABV is only coming to 6.58% and I was expecting somewhere around 9 at least...

Base of 2 row but also had dark candied sugar and sugar in the raw....

I don't think champagne yeast will drop it significantly if T-58 fails.
If you pitched right amount of yeast I wouldn't re-pitch it, possible reasons of high FG are grain bill (fermentability of special malts), high mash temperature and fermentation temperature.

Try to warm it to 70's and if it holds I would bottle it, but decision is up to you.
Good luck.

Can you provide the full recipe and process? Also, how long has it been fermenting and how long has it been stuck?

1.031 is, obviously, high, but if pitching more yeast failed, it might not be stuck, but actually finished. More info about your recipe/process may help determine what's going on.

I'm in the same boat as you. I brewed up Mosher's Caramel Quad recipe (more or less) a few weeks ago and although it is still bubbling a little, after two weeks it is only at 1.038.

Adding wine (Champagne) yeast to a stuck fermentation is not a good idea. Wine yeast do not ferment the complex sugars (maltose, maltotriose), only the simple sugars which are usually gone by the time the fermentation sticks. Wine yeast also have a positive competitive factor causing them to kill competing yeast...namely, the beer yeast.

I've restarted a couple of beers with champaign yeast, but never one that I mashed over 154*. It has worked well. The beer usually finishes dryer than I planned and it takes a long time for the beer to clear, but it works.

YMMV.

This might be a naive guess, but could bean-o break the complex sugars into simple ones and start up the fermentation again?
Obviously this would lead to a thinner beer, but it might work, someone correct me if I'm wrong here.

There have been a number of people that have had this problem recently because they used a refractometer and didn't compensate for alcohol. Although with that high mash temp and low fermentation temp I wouldn't be surprised if it really is stuck at 30.

Yea, we might need some more info from OP. Is the beer really sweet? Did you measure FG with a hydrometer or refractometer?
What was your recipe, esp grainbill? With that high mash temp, you very well may be done, but you should probably warm it way up, swirl some yeast into suspension and see what happens.

I've had decent restarting high gravity brews by boiling a small amount of simple sugar (just enough to sanitize) and yeast nutrient (or baking yeast) and adding that to the fermentor, and then heating it up/swirling. The yeast get woke up by the simple sugar and then if there's anyhtin gelse they can eat, there's some nutrient in there to help them go at it. Just a shot in the dark, though.

Base ingredients
original yeast was white lab wlp500
12 lb two row pale
1 lb dark candy sugar ( beginning of boil /sparg)
1 lb sugar in raw ( beginning of boil /sparg)
1lb of aromatics (munichx2)
8oz of special b
2oz Belgian choc
8oz cara 45

Mashed close to the 158-160 mark, I know that is high and that might be my problem right there. (two different thermometers so it should be right )
All gravity readings are with a hydrometer

My main goal is to bottle this and I want to prevent bottle bombs. I also would like to dry it out a little and get the alcohol up higher.

BTW It is pretty sweet right now.

Yea, I think with that super high mash temp, in combo with high gravity, you may be done BUT I would say definitely try the warming + shaking + little sugar + nutrient (or boiled yeast) and see if you can't get it into the twenties. For this beer, I'd say you want to see identical FG readings a WEEK apart after that before you bottle.

What kind of sugar do I add and do I need to boil it into a simple syrup?

Sorry to distract with the refractoneter inquiry. I wanted to eliminate that as a possibility. The boiling is just to sanitize, so however much it takes to dissolve the sugar. Because you are adding yeast nurturance table sugar would be okay, however corn sugar or corn syrup would be raiser for the yeast to digest.