The answer is to store it like you would the sourdough starter itself. A clear, straight-sided container is perfect for the ...

Those of you who’ve never had a real sourdough have ... time-lapse video of the starter as the beasties within give off their CO₂, thus expanding it up inside its container.

Sourdough starter, an alchemy of flour ... On day 1, put flour and water into a 2-litre storage container (a large glass jar works well). Stir together - this is your starter.