Should I Cover Sourdough Starter?
Covering a sourdough starter is generally wise during storage and between feedings, but the type of cover matters. A loose, breathable cover protects the culture from dust, insects, and drying without trapping the carbon dioxide produced during fermentation. An airtight seal, by contrast, can create pressure, make monitoring harder, and encourage unwanted moisture. The right choice depends on whether your starter is actively fermenting, resting in the refrigerator, or being observed for peak rise.