Lots of good answers here but I still have a question...after all the background info...
1) Big Baltic Porter kit that was supposed to be 9.5-10.8% ABV.
2) Used 5.4% more LME by mistake and added 14 oz. corn sugar alcohol boost kit. OG 1.120
2) Aerated & pitched two yeast packets + NB Fast Pitch.
4) Left in carboy 4.5 weeks for various reasons. FG 1.026 3 days in a row. Yikes...not on the Baltic Porter chart anymore, but probably fermented...
5) Boiled 5 oz. bag of priming sugar in 16 oz water, cooled, mixed into the beer & bottled. 64 F when bottled (was on floor in a tote on cement floor). Air temp a couple feet above floor in cellar 66 F.
6) Waited 4 weeks before opening. Smells sweet, tastes sweet & barely a 'pffft' upon opening & barely 3 mm / 1/8" 'head'.
7) 4 non-beer-judge tasters liked it but no one analyzed taste. Wished it had more carbonation.
8) Put bottles in 6-pack carriers in an opaque Rubbermaid style tote planning to move upstairs...it's rarely above 69 F & where it is would be in a hallway that won't work. Tote was still 66 F inside last night.
9) I am thinking about blowing some warm air from a space heater via a fan and cardboard with heater on low and thermostat set barely above where it sees the cellar temp being...would check air temp & aim for low 70's F for a couple more weeks.
?)
I'm hoping a little warmer conditioning and more time are what it needs. What produces the condition of not being able to carbonate further? Totally exhausted yeast? Is that common? (Used S-189 between 63 and 66 F).
Thank you