Cauliflower

Cauliflower keeps 3–5 days refrigerated and stores much like broccoli, with one difference: it should be kept stem-side up.

The reason is condensation. Moisture that collects on the dense white curd is what causes the brown spotting, and storing the head stem-down lets water pool in the florets. Inverted, it drains away.

Store it in the crisper in a perforated bag, unwashed. Wash it only when you are about to cook.

Keep it away from ethylene producers such as apples and bananas.

Cauliflower freezes well once blanched, for about 12 months. Riced cauliflower freezes particularly well.

Cauliflower, like broccoli, is an immature flower head — but a much denser and more tightly packed one, and that density shapes how it fails.

The characteristic problem is brown spotting on the white curd. This is enzymatic browning, the same polyphenol oxidase reaction that browns a cut apple, triggered by moisture sitting on the surface and by minor bruising. Light brown spots are entirely cosmetic and can be trimmed off with a knife or a vegetable peeler; the cauliflower beneath is fine.

That density also means moisture cannot escape from the interior of the head easily, so once rot starts inside it can be advanced before you see anything. A head that feels heavy and damp in the center, or that smells sulfurous when you cut it, has gone.

Being a brassica, cauliflower contains glucosinolates that break down into sulfur compounds as the tissue degrades. A strong sulfurous or rotten-egg smell is the clearest signal to discard.

Purple or green tinges on white cauliflower are usually sun exposure in the field producing anthocyanins — harmless and unrelated to freshness.

Discard on soft mushy areas, black spotting, sliminess, or a strong sulfur smell.