Oranges

Oranges keep about a week at room temperature and 3–4 weeks refrigerated. Both are legitimate: the counter is better for flavor and juiciness, the fridge for longevity.

In the refrigerator, store them loose in the crisper rather than in a sealed bag. Trapped moisture on the peel encourages mold, and citrus needs airflow.

If you are juicing, bring the fruit to room temperature first — or roll it firmly on the counter under your palm, which ruptures the juice vesicles and can increase yield noticeably.

Do not store oranges in a pile. Bruised fruit molds quickly and spreads to neighbors.

Whole oranges do not freeze well. Zest and juice both freeze excellently, and zesting fruit before juicing is worth the habit.

Citrus keeps well for two structural reasons: a thick, oil-rich peel that is an excellent moisture and microbial barrier, and flesh with a pH around 3.5 — acidic enough that virtually no foodborne pathogen can grow in it.

Oranges are also non-climacteric. They do not ripen after picking, so an orange picked green stays green-tasting. Commercial oranges are harvested ripe, and some are treated with ethylene to degreen the peel — a purely cosmetic process affecting the skin color, not the fruit inside.

The characteristic failure is Penicillium mold — the blue-green fuzzy growth, usually starting at a bruise or the stem end. It is why one moldy orange in a bag takes the rest: the spores are abundant and travel easily.

Because oranges are high-moisture fruit, a moldy one should be discarded whole, not trimmed.

Two things that look wrong but are not: white pith is normal and edible, and regreening — a ripe orange turning partly green again on the tree in warm weather — is a chlorophyll phenomenon that has nothing to do with quality.

Discard fruit that is light for its size and dried out, soft and squishy, moldy, or leaking. A slightly wrinkled peel on a firm orange is only dehydration.