Originally Posted by Dynachrome
..you're saying that it may just have been the movement making the CO2 come out of solution like when you pour a glass of beer?
Raising the temperature can make CO2 come out of solution, and even if it doesn't can expand the gas in the headspace and cause the airlock to bubble.
Moving the beer can make CO2 come out of solution or slightly distort the fermenter and cause the airlock to bubble.
A change in weather (e.g. a low-pressure front moving through) can decrease the external air pressure and cause the airlock to bubble.
A hydrometer can tell you if fermentation is happening. An airlock can tell you if the airlock is bubbling.
On deck: Little Bo Pils, Bretta Off Dead (Brett pale)
Secondary: Oude Bruin, Red Sky at Morning (Sour brown ale)
On tap: Saison Duphunk (sour), Amarillo Slim (IPA), Earl White (ginger/bergamot wit)
Bottled: Number 8 (Belgian Strong Dark Ale), Eternale (Barleywine), Ancho Villa (Ancho/pasilla/chocolate/cinnamon RIS), Oak smoked porter (1/2 maple bourbon oaked, 1/2 apple brandy oaked)