Ask the Experts: How To Blanch Vegetables?

Q: What does it mean to blanch vegetables, and how do I do it? When should I blanch vegetables instead of steaming, roasting or sautéing them?

A: Blanching is a smart technique for any cook to understand and use, whether you're preparing vegetables for an appetizer platter or salad, or planning to freeze them. You can even use blanching to loosen skins on tomatoes and other fruit for easier peeling.

Blanching simply means to cook vegetables briefly and cool them quickly.  A few key reasons to use this technique:

1. Blanching reduces potential surface contamination of vegetables;

2. It deactivates food enzymes, slowing spoilage and loss of nutrients;

3. Blanching enhances flavor and preserves color.

How to Blanch Vegetables

Blanching is quite easy as long as you prep ahead of time. You'll need a large stock pot filled with water, tongs or a slotted spoon, a large bowl filled with ice water, and a clean towel spread out on the counter or another bowl lined with paper towels.

Boil the water as you wash and prepare your vegetables -- trim the ends of beans, remove broccoli and cauliflower florets from stalks, snap off the ends of asparagus stalks. Place a small amount of vegetables in the boiling water, which should return to boiling in less than a minute. Blanch for the appropriate amount of time based on our infographic below. (Additional vegetables and blanching times available from the National Center for Home Food Preservation.)

Blanching time is important because if you cook vegetables too long, you lose the benefits of blanching. But if you don't cook them long enough, it actually stimulates enzyme activity instead of halting it. Watch the timer carefully.

Timing is another reason why it's important to work in small batches. If you add too many vegetables to the boiling water, it will take a while to return to boiling. This will throw off your blanching time and likely result in overcooking.

It's also important to quickly transfer the blanched vegetables to the bowl of ice water, a process known as shocking. This stops the cooking process. Leave the vegetables in the ice water long enough for them to cool. Then transfer them to the clean, dry towel or paper towel-lined bowl.

When to Blanch Vegetables

Blanching is a helpful technique for preparing summer dishes when vegetables are at their peak. Try blanching snap peas, carrots, cauliflower and broccoli for appetizer platters; they'll look and taste better than raw. You can also blanch vegetables that will be added to pasta salads and other dishes served cold or at room temperature. Finally, blanch before freezing to keep vegetables as fresh, delicious and nutrient-packed as possible.