Still bubbling on day 13- troubling

[Limited Repertoire]

I am fermenting my second all-grain batch; a brown SG 1.046; and it is day 13 since it started, and it makes a bubble every minute and a half. This seems like a long time; do I have an infection?

[Tygo]

It's probably just off gassing CO2. One bubble every minute and a half isn't an indicator of much activity. Also, watching the bubbles isn't a great indicator if the beer is done. Take a gravity reading. Taste the sample. Does it smell and taste right?

[spiderwrangler]

13 day ferment is not unheard of... depending on a number of variables. That's why I don't like recipes that tell you do do things after a certain number of days... Like if the beer isn't ready to bottle on day X, don't do it!

[Limited Repertoire]

The gravity is 1.012, and the taste is fine.
There is a big cap of yeast on top of the beer. I don't usually see that, though this is the first time I have used London Ale yeast (WLP 013).
I will probably bottle it today, and we'll see!

[brewinhard]

If it is bubbling that slowly then your beer is done and it is most likely CO2 outgassing from the fermenter. Have no worries, package up your beer and enjoy!

[BDawg]

+1 on degassing. A temperature change (ie, beer getting warmer) will drive gas out and cause slow bubbling.
Check the gravity. Also, a fallen krausen will also indicate that it's pretty much done with primary fermentation and is now only processing the byproducts to clean up after itself.

[Billy Klubb]

beer bong the whole damn thing. if it tastes good, it's done. if it's too sweet, you shoulda waited.

[spiderwrangler]

Let it keep going... Do NOT bottle it too soon.