Why do vegetables at a chef’s always look brighter than at your home? Chances are that blanching is the secret. It costs you only a few extra minutes, and the difference is visible and tasteable.

Blanching is dipping vegetables (or fruit) very briefly in boiling water and then cooling them straight away in ice-cold water. That keeps them crisp, bright and full of flavour, and you can then prepare them further: stir-fry, use in a salad or freeze.

What is blanching?

Blanching is an intermediate step in the kitchen. You don’t cook the vegetable fully, but just enough to fix the colour, keep the bite and deactivate enzymes. Then you stop the cooking abruptly with iced water.

The word comes from the French blanchir, to whiten. Originally it was used for whitening meat and vegetables, but nowadays it mainly stands for the short dip in boiling water.

The difference with boiling is the duration and the cold water afterwards. The difference with steaming is that here the vegetable does lie in the water.

Why does the colour stay so bright?

Green vegetables get their colour from chlorophyll. With brief heating the air disappears from the tissue, and the colour comes out brighter. With longer cooking the chlorophyll breaks down and the vegetable turns dull. By cooling the vegetable straight away afterwards, you stop that process and the bright colour is preserved.

Briefly hot, then ice cold: that is blanching.

How to blanch vegetables in 6 steps

Fill a large pan with plenty of water. Count on at least 3 litres for 500 grams of vegetables: with a lot of water the temperature doesn’t drop when you add the vegetables.
Salt the water generously, about 2 teaspoons per litre, and bring it to the boil.
Set a large bowl of cold water with plenty of ice cubes ready.
Add the vegetables, preferably in batches, so the water keeps boiling. Cut the vegetables into equal pieces, then everything is done at the same time.
Boil briefly (see the table below) and lift the vegetables out of the pan straight away with a slotted spoon.
Let the vegetables “shock” in the iced water until they are completely cold, about as long as they boiled. Then drain well and pat dry.

Tip: that “shocking” in cold water is not an unnecessary step. It stops the cooking process immediately, so the vegetable stays crisp and doesn’t keep cooking.

How long should you blanch?

The time depends on the thickness of the vegetable. These are guide times, counted from the moment the water boils again.

Vegetable	Blanching time
Broccoli and cauliflower (florets)	2 to 3 minutes
Green beans and haricots verts	2 to 3 minutes
Green asparagus	2 to 3 minutes
White asparagus	4 to 6 minutes, depending on the thickness
Peas and mangetout	1 to 2 minutes
Sliced carrot	2 minutes
Brussels sprouts (halved)	3 to 4 minutes
Savoy or white cabbage in strips	1 to 2 minutes
Sliced courgette	1 minute
Spinach and chard	30 to 60 seconds
Tomatoes (for peeling)	10 to 30 seconds
Almonds (to remove the skin)	1 minute

Always taste a piece: the vegetable should be tender-crisp, so still have a nice bite.

Why would you blanch?

Bright colour. The short heat and fast cooling keep the colour clear, so green vegetables stay green.
Crisp bite. The cold water stops the cooking directly, so the vegetable doesn’t turn limp.
Prepare ahead. Handy if you still want to stir-fry, stew or make a salad later. The vegetable is then almost ready.
Easily remove the peel or skin. With tomatoes, peaches and almonds the skin slips right off after blanching.
Tame sharpness. For example with citrus peel, which you blanch to soften the bitterness.

Blanching for the freezer

Vegetables you are going to freeze are blanched first. The heat deactivates enzymes that would otherwise break down flavour, colour and texture over time. Blanch the vegetable according to the table, let it shock and drain well, and divide it into portions in freezer bags or containers. That way the quality stays good for about a year.

Blanch and shock the vegetable according to the table.
Drain it well and pat it dry.
Lay the pieces loose on a baking tray and pre-freeze them for a few hours.
Put them in freezer bags or containers and press out the air.
Write the date on them and freeze.

That way the pieces don’t stick together and you can take exactly the amount you need.

Blanching for peeling

The skin of tomatoes, peaches and almonds is easiest to remove by blanching them. Cut a small cross in the bottom of the tomato, dip it in boiling water for 10 to 30 seconds and shock it in iced water. The skin then slips right off. With almonds you blanch for 1 minute and squeeze them out of the skin.

Blanching in the kitchen: when do you do it?

Situation	Blanch?
Freezing vegetables	always
Vegetables for a cold salad	yes, for colour and bite
Stir-frying with hard vegetables	yes, 1 to 2 minutes
Peeling tomatoes	yes
Soft vegetables such as pepper and courgette	usually not necessary
Vegetables you want to eat cooked straight away	no, simply boil or steam

Common mistakes

Too little water. The temperature then drops sharply, the water stops boiling and the vegetable turns limp and dull.
Boiling too long. Then you are simply boiling and the colour and bite disappear.
Skipping the iced water. Just draining is not enough: the vegetable keeps cooking in its own heat.
Wet vegetables in hot oil. Pat the vegetable thoroughly dry first, otherwise it will spatter.
Vegetables of different thickness together. Thin pieces are done while thick ones are still hard. Cut equally or blanch separately.

Recipes in which you blanch

Salade Niçoise: blanch the haricots verts for 2 to 3 minutes.
Grilled bavette with rocket and Parmesan: blanch the green asparagus.
Orloff roast with mushroom cream sauce: blanch the peas for 2 minutes.
Pork cheeks with brown beer and savoy cabbage: blanch the savoy cabbage briefly.

Practise with green beans

Remove the stalks from a handful of green beans.
Bring a pan with plenty of water and salt to the boil and set a bowl of iced water ready.
Blanch the beans for 2 to 3 minutes.
Scoop them straight into the iced water and let them shock for 2 to 3 minutes.
Drain them and taste: crisp and bright green.

Then boil a second portion of beans for 8 minutes and compare the colour and the bite. That way you see straight away what blanching does.

Frequently asked questions about blanching

What is the difference between blanching and boiling?

With boiling you cook the vegetable completely. With blanching you cook it only very briefly and stop the process straight away with iced water. The vegetable is then tender-crisp and is prepared further or frozen.

Do you have to blanch vegetables before stir-frying?

Not always. Hard vegetables such as broccoli, carrot and green beans cook more evenly and keep their colour if you blanch them first for 1 to 2 minutes. Soft vegetables such as pepper and courgette don’t need to be.

Can you also blanch fruit?

Yes, mainly to loosen the skin of tomatoes and peaches. Cut a cross in the bottom, dip the fruit in boiling water for 10 to 30 seconds and shock it in iced water. The skin then slips right off.

Can you do it without iced water?

Cold running water also works, but iced water stops the cooking faster and holds the colour better.

Does the water need salt?

It isn’t necessary, but salt gives the vegetable flavour from the inside. Vegetables you blanch in unsalted water taste flatter.

How long can you keep blanched vegetables?

Well drained and covered, blanched vegetables keep for 2 to 3 days in the fridge. In the freezer they keep for about a year.

Blanching at a glance

Blanching is briefly hot, then ice cold.
Use plenty of generously salted water.
Blanch in batches and cut evenly.
Shock the vegetable in iced water.
Pat the vegetable dry before preparing it further.
Always blanch before freezing.
Also use it to peel tomatoes and peaches.

Remember this

Blanching seems an extra step, but it is one of the cheapest ways to make vegetables look better and taste better. It isn’t about exactly 2 minutes. It is about control: heat briefly, cool immediately and prepare further.

You can find more techniques under Basiskennis, such as boiling, steaming and stir-frying.