We've all encountered a recipe calling for chopped fresh mint or basil and had to wait until the absolute last minute to cut it so the herbs don't turn black (bit of a pain, right?). Well, it turns out there's an easy solution: blanching. This simple and quick technique keeps fresh chopped herbs vibrant and green.
Blanching herbs is easy. Start by bringing a pot of water to a boil. Drop in the herbs and flash boil. About 15-30 seconds for tender herbs, and 30-45 seconds for heartier herbs. Spoon out the herbs and immediately run them under very cold water. Drain and dry well.
There are three key effects of blanching herbs: the process will help maintain their vibrant colour and resist the tendency to turn black, but it will also mellow the flavour. This technique is perfect for recipes where you want your herbs to remain bright—either as a garnish or as a main component in the dish. It is also ideal for make-ahead meals, when you need to prepare an entire dish in advance (such as for a fruit salad or salsa). It is also the perfect fix for pesto or herb-based soups where a vibrant green colour is vital to the appeal of the dish.
Blanch whole mint leaves for 30-45 seconds prior to chopping. This ensures the leaves won't turn black once partly cooked. Mint's a very hearty herb, so it will retain its shape beautifully when blanched taking on an even more vibrant green colour. And, it'll become slightly more delicate in texture, removing a bit of its woodiness. Blanching does subtly mellow the 'minty-ness'—so you may need to increase the quantity you use. Once rinsed, transfer to a paper towel to let dry, and then store in the refrigerator. Try adding blanched mint to your next fruit salad.
Blanch thyme using the entire sprig for about 45 seconds. Like mint, blanching thyme removes a bit of its woodiness, making the texture more delicate but slightly more subtle in flavour. Blanched thyme is ideal for soups and chowders where the leaves are still added whole so you want them to remain green and vibrant.
Basil is a very delicate herb and should only get blanched for between 15-30 seconds. Because of its thin, soft nature, it loses its shape quickly. Blanched basil is only a candidate for dishes where the herb is meant to be well-cooked or pureed, such as a sauce or pesto.
Much like basil, cilantro is also a very delicate herb. It too should be blanched for a maximum of 30 seconds. Cilantro likes to retain water, so it needs adequate time to drain or give it a slight squeeze to remove excess water after blanching. Blanched cilantro is perfect for soups and salsas.
Blanching remains an ideal step to take before freezing herbs. If your herb garden is overflowing (what a wonderful problem to have) be sure to blanch and freeze your herbs (in a plastic bag) so you'll have lovely, vibrant herbs all year long. Find more tips on storing herbs.
Originally published June 2015; Updated June 2019.
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