Ever have a batch that was slow to carb up

In Bottles?

Just about every batch of IPA I've done has carb'd in two weeks. But, I did a Fat tire clone out of BYO (don't ask me why), and it's been bottled over four weeks and is still pretty lame as far as carbonation goes.

I'm kind of leaning towards the yeast even though it finished out within the FG specs on the recipe. (WLP051). I normally use safale 05 on the IPA and it's been great.

The bare minimum for most average grav beers is 3 weeks at 70 degrees.

it really has little to do with "the yeast" like you think.....

Gravity and storage temp are the biggest factors in carbonation/conditioning times...Less than seventy severely slows down the yeast...2 degrees may seem like nothing to us, but to micro-organisms that could be like 10.

ALL beers will reach their level of carbonation eventually. In fact, it's possible (and proven by running the numbers in beersmith) to NOT add priming sugar and get minimal carbonation/style of a few volumes in time (in old brewing british brewing books they didn't add sugar to some ordinary bitters, and milds and relied on time and temp to do the work naturally.)

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.

More info can be found here....Revvy's Blog, Of Patience and Bottle Conditioning.

There's even a nifty video in their of carbonation over the weeks.

Lazy Llama came up with a handy dandy chart to determine how long something takes in brewing, whether it's fermentation, carbonation, bottle conditioning....

LOL, well Fat Tire is quite a bit lower on the OG than the IPA I usually do. That's what makes me question the yeast. I keep everything in my reloading/(now) fermenting room in the basement @68*

I know it will eventually carb up and I can wait since it's not something I normally
drink. Just wondered.

I had an ESB that I messed up the priming sugar for. I basically put in less than half the sugar. So after 2 weeks... it was flat as can be. I forgot about it when life got really busy. 4 weeks later, it had a little fiz. Another 2 weeks and it was spot on what I wanted. So it took almost 2 months but then it was a great beer!