What is Blanching

When you find fresh vegetables at the farmers market — snappy asparagus, fuzzy fava beans, sweet peas — it’s an invitation to shift away from the braising and stewing hearty root vegetables and instead to embrace a quicker process. Blanching, a technique in which vegetables are cooked briefly in boiling salted water and quickly submerged in ice and water, is the name of the game for these tender offerings. The technique is often associated with green vegetables (like in Spring Peas with Mint Butter or Yu Choy with Garlic Sauce), but the simple process works for many types of vegetables.

One major benefit of blanching is that you can do it well ahead of serving; simply warm the vegetables in, say, browned butter (like in this Sweet-and-Sour Glazed Carrots), or toss them with a vinaigrette or herbs (see Asparagus Salad with Smoky-Sweet Gremolata) when it’s go time.

What is blanching?

Blanching is a cooking technique where vegetables (and occasionally fruits) are briefly submerged in salted boiling water and then immediately cooled in a bowl of ice and water. 

Why should you blanch?

Aside from being both simple and quick, blanching is a terrific way to hold vegetables at the perfect stage of doneness: Boiling brings them to crisp-tenderness, and the dunk in ice and water sets their texture. 

Blanching also enhances the color of green vegetables. The stint in boiling water releases color-clouding gas between the cells of the vegetable, which makes the bright green of chlorophyll more visible. The ice bath, too, is critical for locking in that verdant color. If you simply drain the vegetables, they risk overcooking and dulling; the shock of the ice water helps them cool quickly enough to prevent that from happening.

What kind of liquid is best for blanching?

Perhaps my favorite thing about blanching is that it relies on the most basic ingredients in the kitchen. Tap water, which is typically slightly alkaline, has an ideal pH level for the process — more acidic solutions break down chlorophyll and result in a dull color. There’s no need to blanch in stock or wine, as the cooking time is so brief the liquid doesn’t make a big impact on flavor. All you need is to salt the cooking water to a light salinity — just enough to season the vegetables while still allowing you to control the overall flavor when you finish the dish. (To coax out a little additional umami, season with a bit of MSG, as well.) 

How to blanch

1. Bring water to a boil

Bring a large pot of water to a boil over high. Season to a light salinity with salt.

2. Cook the vegetable

Add the vegetables to the boiling water, one type at a time, and cook just until crisp-tender.

3. Remove using a spider

Remove vegetables from boiling water using a spider strainer or slotted spoon.

4. Shock in ice water

Transfer vegetables to a large bowl filled with ice and water. Let stand until completely cooled. Drain well; pat dry with paper towels.

How long to blanch

Use this chart as a guide for how long to cook vegetables in boiling water. Once their time is up, immediately transfer them to a large bowl of ice and water to let cool for 2 minutes. Season the boiling water to a light salinity; if using MSG, stir in 1 1/4 teaspoons MSG and 1 tablespoon kosher salt for every 1 quart water.