Big Honkin Stout + Cherries

My fifth homebrew is a NB Big Honkin Stout extract:

http://www.northernbrewer.com/brewi...ct-ale-kits/big-honkin-stout-extract-kit.html

After the boil and around 150F I dropped in the oregon pureed cherries, 1 3lb can. I added enough water to the better bottle to hit 5 or so gallons. My OG was 1.075. The kit is listed as 1.068, so i figured that the extra points came from the cherries. I though in my safale US-05 and went to bed. 8 hours later the thing was raging in the bottle with blowoff tubing. A week later, I took a grav measurement. I read 1.026. I figured it still had some work to do. A week later, still 1.026. Put in a half a packet of champagne yeast. Week later, 1.026. I figured that perhaps the yeast had gone dormant (I did keep it cool, around 65F, in a water trough with some ice formed in water bottles), and I was worried about bottle bombs, so I racked it to secondary without any cooling and hoped the yeast would reawaken. Week later, 1.025. Aaargh!

I need bottle it this week. I am worried that my yeast have pooped out, but that doesn't make sense with the bubbles I still see every day. I am thinking about adding some more yeast with my priming sugar to make sure I get good carbonation. Does that make sense? More importantly, was was my FG high? I am beginning to wonder if in actuality my OG was mis-measured; the kit is listed as a 1.068 OG, and from what I read on the web the cherries could add 15 or 20 points. This would push my attenuation into the 70s, which I am more apt to believe. Anyone have some comments?

EDIT: I do not use any tap water. I boil with water that comes out of machines in front of the grocery store (so I know its good but not sterile) and top off the primary with bottled.

I just checked the recipe, and the OG should have been around 1.074 without the cherries. Cherries are around 14% sugar, so the 15-20 points is right, but thats per gallon, so only really 3-4 points more. It did finish a little high, but with all the dark malts in it I'm not really surprised. Try gently swirling the carboy and letting it warm up a bit. If that doesn't get it any lower, and you need to rack it this week, you may just want to prime with a little less than usual.

Any reason you added the cherries after the boil??
Usually it is best to add at secondary time.

@dcp27: That's a good check, thanks for doing that! I started looking myself in BeerTools about what NB quotes, it definitely changes from time to time. Everything you said tracks with what I measured as well. I ended up racking and bottling last week. I tried a week old bottle and was shocked to pick up a plastic taste... scared me. I think its from new vinyl tubing from home depot... I should of been more vigilant. Of the bottles I tried the taste varied; I think some bottles got more plastic just because the first runnings really cleared the taste out and the later bottling were less plasticy. What's more surprising is that it was a very short (2 inches) of 3/8in tubing to connect the bottling spigot to the bottling cane... scary. I cross my fingers the taste dissipates over time! To neutralize the problem I bought a new racking cane (it was cracked), and more tubing from NB. A long soak in OneStep should put me at ease.

At bottling I added half a pack of champagne yeast and 4/5 of priming sugar package. My guess is the yeast just gave up at the gravity of the brew, not enough o2, or perhaps nutrient levels. Let's see in two weeks how the carb went.

@SevenFields: I wanted to have just a hint of cherry and not a large amount of taste in the beer. So I went with a moderate amt of cherries and primary. The outcome is a stout with no cherry-ness at all! Not surprising after reading other people experiences. I may try 6lbs in the primary or 3 in the secondary next time.