Blanch

To blanch is to expose food briefly to a hot cooking medium, most commonly boiling water, then often cool it rapidly to stop the cooking. Blanching may be used to set colour, partially cook an ingredient, loosen skins, reduce bitterness or remove excess salt or strong flavours.

Common blanching applications

• Vegetables: briefly cook green beans, asparagus or broccoli before shocking in ice water.
• Tomatoes: dip briefly in boiling water to loosen the skin before peeling and concassé preparation.
• Bacon or lardons: blanch in water to reduce some surface salt and strong cured flavour before further cooking.
• Potatoes: some preparations use a preliminary blanch in water or oil before finishing by frying or roasting.

Blanching and shocking

When the goal is to stop cooking and preserve a crisp-tender texture, transfer the blanched food immediately to an ice-water bath. Drain thoroughly once cold. Some recipes do not require shocking; the method depends on the intended result.

Why blanching matters

Blanching provides controlled partial cooking and can make later preparation faster. It does not automatically sterilize food or make it safe for extended storage.

Chef’s tip: Use enough hot water to recover temperature quickly after adding the food, work in manageable batches and time each batch consistently. Use a calibrated thermometer and follow approved cooling and storage procedures.

Key distinction: Blanching is a brief initial heat treatment. Shocking is the rapid cooling step that may follow it.