Water & Steam

Blanch

Plunge briefly in boiling water, then shock cold to lock color

Blanching dunks food in boiling water for seconds to a couple of minutes, then drops it into ice water to halt cooking. It sets vivid color, loosens skins, and tames raw bite. Have the ice bath ready before you start — the cold shock is half the technique.

Blanching plunges food into boiling water for a short burst — seconds to a couple of minutes — then immediately shocks it in ice water to halt the cooking. That one-two of heat-then-cold sets vivid color, loosens skins, tames raw bite, and pre-cooks vegetables for the freezer or a quick final sauté. It's a prep technique as much as a cooking one: blanched green beans stay brilliant and snappy, blanched tomatoes and peaches slip out of their skins, and blanched broccoli is ready to finish later in seconds. The ice bath is half the technique — have it ready before the water even boils.

Difficulty: Easy

Types & varieties

Shock blanch

Brief boil then ice bath to set color and stop cooking — the standard.

Skin-loosening blanch

A quick dip to slip skins off tomatoes, peaches, and almonds.

Par-blanch

Slightly longer to partly cook vegetables ahead, finishing them later by another method.

How to do it

1
Prep the ice bath first
Fill a large bowl with water and plenty of ice before you start — the cold shock has to be instant to work.
2
Boil generously salted water
Bring a big pot to a rolling boil and salt it well; lots of water keeps the temperature up when food goes in.
3
Drop food in briefly
Add vegetables and start timing — often 30 seconds to 2 minutes; they should turn vivid and just-tender, not soft.
4
Shock immediately
Scoop the food straight into the ice bath the second it's ready to stop the cooking cold and lock the color.
5
Drain and dry
Once fully chilled, drain and pat dry; surface water dilutes sauces and causes freezer ice crystals.

The science of color and the shock

Brief boiling drives the dull gases out of vegetable cells and brightens chlorophyll, turning greens electric — but leave them too long and the same heat breaks the pigment down to drab olive. The ice shock arrests cooking instantly so the vegetable stops at peak color and crispness instead of carrying over to mush. Blanching also deactivates the enzymes that degrade color, flavor, and nutrients over time, which is exactly why it's the standard prep step before freezing vegetables.

Common uses

Green beans, asparagus, and broccoliLoosening tomato and peach skinsSpinach and leafy greens before squeezing dryPrepping vegetables for the freezerPar-cooking before a quick stir-fry or sautéBlanching almonds to slip their skinsCrudités platters with brighter color and bite

Tips & pitfalls

Have the ice bath ready before the water boils — there's no time to make it once food is in.
Salt the boiling water hard; it seasons and helps keep greens green.
Blanch in batches so the water stays at a rolling boil and the timing stays precise.
Dry blanched vegetables thoroughly before freezing or saucing.