I have brewed a barleywine recently with an OG of 1.100 using US-05 it fermented down to 1.013, so it's at about 11.5% ABV. Unfortunately, I did not expect this beer to ferment so low. I bottled on May 6th, so it's right at 7 weeks in bottles. I have opened 3 total; one at week 5, one at 6, and tonight at week 7, there has been no carbonation to speak of. The beer has a slight "pssh" sound when I open it, but even with the most aggressive pour, only the slightest head appears (I'm talking only a few bubbles that can be attributed to CO2 and not splashing when pouring) and no signs of full carbonation.
I know big beers=more time, but after 7 weeks, shouldn't there be more than this? I'm thinking that the yeast has crapped out, and I may need to open the bottles again and re-dose with champagne yeast or something. The problem is, there is a slight "pssh" upon opening bottles, and I don't want to lose any carbonation that may happen... Any advice? This would be a terrible investment to lose.