Using airlock cap

[Heesuk]

Is it healthy for the water kefir to use an airlock cap during the first ferment instead of a cloth with rubberband? Is it healthier for the kefir grains to do their work with a wide mouth jar versus a narrower one?

[AlexP]

It's mostly personal preference, but generally an air lock will create more lactic acid bacteria and be less yeasty. While it may encourage some strains, it may also minimize other strains that like oxygen. Traditionally, kefir was done in an open air environment. One is not necessarily healthier than the other. As far as wide-mouth vs regular-mouth jars. I prefer wider jars vs skinny jars, but the wide-mouth jars are mostly just wider at the top, so it ultimately doesn't really matter that much in my opinion.

Alex