I bottled my blueberry ale on December 20 with a FG of 1.014, about what I expected. I used the packet of corn sugar that was included in the kit when I racked to the bottling bucket, just like I always do but this time I put some in a plastic water bottle, the thin ones that crackle when you pick them up empty so I could have an indicator of when the beer might be carbed. The next day, about 24 hours after bottling it, that thin plastic bottle was rigid and the bottom was pressed out signaling that there was pressure already. I won't open it yet as I know that it needs more time to mature but I'm pretty sure if I chilled it for 24 hours, I would have carbonated beer. The temperature of the carbonation area has been a constant 74 degrees F.
Just because your bottle is hard doesn't mean that the beer is carbed, that the co2 has actually gone into the solution.
Bottle carbing is a NATURAL process, you can't really rush something.
The
3 weeks at 70 degrees, that we recommend is the
minimum time it takes for average gravity beers to carbonate and condition. Higher grav beers take longer. Lower temperatures take longer.
And just because a beer is carbed @ three weeks, doesn't mean that it doesn't still taste like crap and won't need more time to condition.
Stouts and porters have taken me between 6 and 8 weeks to carb up..
I have a 1.090 Belgian strong that took three months to carb up.
Temp and gravity are the two factors that contribute to the time it takes to carb beer. But if a beer's not ready yet, or seems low carbed, and you added the right amount of sugar to it, then it's not stalled,
it's just not time yet.
Everything you need to know about carbing and conditioning, can be found here
Of Patience and Bottle Conditioning. With emphasis on the word,
"patience."