Onions: whole and cut are stored differently

Useful to know

All dry onions are stored in a cool, dark and well-ventilated place. The chopped onion is refrigerated in a tightly closed container. These are two different guidelines in university leadership, not variants of the same rule. [1]

When buying, choose dry, hard heads without injury. Before use, rinse under running water. Red onion slices have been suggested for sandwiches and salads as a way to add flavor and crispness. [1]

If a recipe uses only half a head, still in preparation choose a pot for the rest. Do not return it to the whole chapters with the expectation that the conditions remain the same.

Preparing small amounts according to plan is more understandable than indeterminately "cut everything in advance". Write down which next dish the rest is intended for, so that the container does not turn into a forgotten remnant.