Blanching is a great cooking method to add to your toolkit, and it turns out that some veggies are actually better off that way. If you’ve heard about it but you’re not really sure how to do it, you’ve come to the right place. H
Blanching is a cooking method done by poaching fruits and vegetables, gently and quickly, in boiling water. The quick part is important. "Blanching" is not the same as "boiling." Usually the dunk is a minute or two and can be as quick as mere seconds. You’re not boiling the ingredient to cook it completely through; blanching is done to just soften or cook the exterior. That’s why it’s normally a good cooking method for vegetables where you want to tenderize the exterior to take any bitter tannins and woodiness away, like with green beans or asparagus.
The second part of blanching is usually an ice water bath. Anything that has freshly been removed from a heat source, whether it’s the oven or the microwave, retains heat. This interior heat can continue cooking the item for minutes. That might sound like no big deal, but something you want to gently cook for 20 seconds just to brighten it up can end up losing its snappy quality from what’s called carry-over cooking. This cooking can be stopped in its tracks with a dunk in ice water.
Admission: I’m a little lazy; it’s a small batch of veggies I just run it under cold water. You can be better than me and make an ice bath.
If blanching doesn’t cook food completely, why do it? The main reasons you’d even consider blanching, or why you see it in recipes, are because you want to hold onto the integrity of the interior for some reason, or the vegetable is particularly bitter.
Let’s talk about bitterness first because it’s very specific. Boiling leaches away some properties of vegetables, including flavor. This is why boiling isn’t usually the most recommended method for cooking everything —you can lose flavor to the water and, if it’s not soup, that ends up down the drain. However, unpalatable bitter flavors can be solved with a long blanch. My favorite example, because it’s disgusting unless it’s blanched, is broccoli rabe. If you don’t think you like broccoli rabe, please read this, and try cooking it again.
As far as keeping the interior untouched, blanching makes it possible to take the raw edge off of some vegetables, while still keeping them crunchy or snappy. It’s a great way to improve a crudité platter. Another excellent use is taking the skin off of some fruits. You might do this with tomatoes for silky sauce that doesn’t have those curled-up skin bits floating around, or for peaches so you can make a delicious peach pie or peach crisp.
The amount of time that you dunk something in slowly boiling water will vary depending on what the food is, and the result you want. If I’m blanching green beans, it only takes about one minute for a nicely dressed side dish. They’ll be softened and less bitter, but not in the least bit floppy or mushy.
Blanching something very delicate can be tricky business. Sometimes asparagus or snow peas can overcook in a few seconds. For these items, the pour-over blanch is better. Set the veg into a colander and simply pour boiling water over them. This flash of hot water is just enough to cook the outside without wilting the most fragile parts.
Blanching is fast, so you want to be ready for the next move. Set a large pot on medium heat with a lid on it and bring the water to a boil. While that’s happening, fill a large bowl with cold water and add a cup of ice. Have the veggies prepped (trimmed or cut if needed), an easy timer to use, and a wide slotted spoon to plunge and scoop out the food.
When the water is boiling, remove the lid and add a bit of salt—a half-teaspoon is fine for a medium pot. Add a handful of the veggies. If the pot is large, you can add more, but you don’t want the water to cool down so much that it stops boiling; you’ll probably be working in batches. Activate your timer for however long you need to. Use the slotted spoon to plunge the veggies so they submerge completely. When the timer is up, scoop 'em out.
Drop the veggies straight into the ice bath and use the spoon to submerge them. You might actually see the color of the vegetable really brighten at this moment. Get all of the veggies in the cold water as soon as possible. After 20 seconds or so you can scoop them out onto a wire rack to drip dry. They’re ready to use.
Cruciferous veggies are often tough and hold some bitterness so they do really well with blanching. Try doing this with broccoli, cauliflower, green beans, asparagus, and thin heirloom carrots. I highly recommend this method for peeling tomatoes and peaches too. Cut a shallow “x” on the bottom of either fruit, blanch for 20 to 30 seconds, and when you take them out of the water bath you’ll feel the skin slip right off.