Asparagus

Asparagus keeps 3–5 days refrigerated, and the storage method makes a genuine difference here — more than for almost any other vegetable.

Treat it like cut flowers. Trim an inch off the bottom of the stalks, stand them upright in a jar with an inch or two of cold water, cover the tips loosely with a plastic bag, and refrigerate. Stored this way, asparagus stays firm for well over a week instead of going limp in three days.

If that is impractical, wrap the cut ends in a damp paper towel and store the bunch in a bag in the crisper.

Use it as soon as you reasonably can. Asparagus is one of the vegetables that most rewards being eaten promptly, because its sugars convert rapidly after cutting.

Asparagus freezes acceptably blanched, for about 8 months, though the texture softens.

Asparagus is a shoot — a young stem cut while actively growing — and it does not stop growing when harvested. That is the key to understanding it.

A cut spear continues to metabolize at a high rate, and it will even keep elongating and try to open its tip. To fuel that activity it consumes its own sugars and converts them into lignin and fiber, which is why asparagus toughens noticeably within days and why day-old asparagus is sweeter than week-old asparagus. Its respiration rate is among the highest of any vegetable.

Standing it in water works because the stalk continues to draw water up through its vascular tissue, maintaining turgor exactly as a cut flower does.

The tips are the most perishable part — tightly packed, delicate, and the first to go slimy or mushy. Judge a bunch by the tips rather than the stalks.

Woody, fibrous stem ends are normal and should be snapped or cut off; they are lignified tissue, not spoilage.

Discard asparagus with slimy or blackened tips, limp stalks that will not revive in water, or a sour smell. The characteristic effect on urine, incidentally, is asparagusic acid and has nothing to do with freshness.