I have experienced the bubbling airlock for 25 days or so, I asked around here and the general consensus was off-gassing. Having said that, I took a gravity reading at 20 days and had about 1.020, my OG was 1.060. I decided to give the fermenter a good swirl let it warm up to about 70 degrees and wait a week. 25 days out I still had bubbles in my airlock. I said F it and bottled exactly 28 days (4 weeks from pitching), when I took my gravity reading it was 1.018. I understand how outgassing may happen, but my estimated FG was 1.015. This was an extract brew, so I don't think the gravity was gonna drop any further. At any rate, yes, I have experienced a "long" fermentation. This was my 3rd brew and the other two quit bubbling within 7 days so I was a little uneasy about this brew creating bottle grenades. I am glad I swirled, warmed and waited I think it was worth it. IMHO (bear in mind I am no expert and still pretty new to this) I think sometimes it just takes a while. My yeasties must have got drunk off the brew and taken a siesta!