Originally Posted by YooperBrew
Well, your OG reading is incorrect. Maybe the top up water and extract didn't mix well, and you got a heavier reading or something like that.
15.5 pounds of LME is alot, but your OG for 6 gallons is more like 1.093. If the gravity is now 1.035, it's probably finishing up. I would expect it to finish around 1.023-1.025 or so (70-72% attenuation). That's still a darn big beer, and may be pretty sweet if you didn't increase the hops when you increased the malt but it'll be more like 8.5-9% ABV when done if the yeast can take it. Most ale yeast strains peter out by 9% ABV or so.
Just what I was thinking, but I'm too lazy to calculate it out.
Also, if it says 5 gallons then it likely means after everything is said and done. 6 gallons after the boil, 5.5 gal into the fermenter, and 5 into a keg. No need to mess with it.