Caper

A bud, not a berry

Capers are the unopened flower buds of Capparis spinosa, a trailing shrub native to the Mediterranean. If left on the plant, the buds open into white flowers with long purple stamens — attractive but commercially worthless. They must be picked by hand before they open, which is why capers remain expensive despite the plant growing prolifically in poor, rocky, dry Mediterranean soils.

The pickling transformation

Raw capers are bitter and astringent — essentially inedible. Brining or salt-curing activates the enzyme myrosinase, which converts glucosinolates in the bud into rutin and the volatile mustard-oil compounds that produce the characteristic sharp, tangy, faintly mustard-and-lemon flavor. This flavor development takes at least several weeks.

• Brine-packed capers — stored in a salt-vinegar solution; rinse before use to reduce saltiness
• Salt-packed capers — buried in coarse salt; considered superior in flavor; rinse and soak before use

Size and grade

Capers are graded by diameter. Smaller is generally considered better — the smallest, “nonpareil” grade (under 7 mm), are prized for their firm texture and concentrated flavor. Larger capers have a more robust, sometimes earthier flavor.

Caperberries are the full ripened fruit of the same plant — the size of a small olive, with a long stem attached. Less common, used as garnishes or eaten whole as an appetizer.

A Sicilian staple

Sicily produces some of the world’s finest capers, grown on the volcanic slopes of Pantelleria and the Aeolian Islands. Pantelleria capers (salt-packed) have protected geographical indication (PGI) status and are considered among the best in the world.