All those tubs of basil-rich pesto at supermarkets can't hold a candle to fresh, homemade pesto made with brilliant in-season basil. The only problem is that basil has a bit of a short season. When it's big and bushy at the end of summer, giant bundles of this fragrant herb can be had for a song, perfect for making giant batches of pesto. And you don't have to eat it all right then, either, since pesto freezes beautifully!
Freezing pesto is super easy. As with most things, you freeze it by putting it in the freezer. And yet... for the best results there are a few tips to follow. There are two ways to go about freezing pesto, each with different end-uses. I tend to freeze pesto both in larger amounts (1/2 to 1 cup) that can be tossed with pasta for a quick dinner and smaller amounts (1 to 2 tablespoons) that can be added to other dishes for a burst of basil pesto summer flavor when the weather turns less sunny.
How To Freeze Larger Amounts of Pesto
To freeze larger amounts of pesto—from 1/2 cup and up—simply transfer the pesto to a sealable container, cover the surface of the pesto with a layer of olive oil, cover or seal the container, and freeze.
That layer of olive oil will minimize browning on the surface of the pesto as it freezes.
How To Freeze Small Amounts of Pesto
While you can freeze pesto in full-batch amounts, I also like to freeze pesto in smaller portions that can be used as quick flavor-enhancers without being the full flavor force of the dish—to swirl in soups or stir into salad dressings, for example.
To freeze small amounts of pesto: put the pesto into ice cubes trays, freeze, and transfer the cubes to sealable plastic bags. Whenever you want a little hit of summer basil flavor, just toss a cube or two of the pesto ice cubes into soups, toss with pasta, or defrost and spread onto sandwiches.
In either case, use frozen pesto within about 6 months.
How to Keep Frozen Pesto Green
As mentioned above, covering the surface of pesto with a layer of olive oil will help keep the surface from browning while it freezes.
For truly brilliantly green pesto, though, you need to start at the beginning: the basil. Before whirling the basil leaves into the paste that is pesto, give it a quick dunk in boiling water (a.k.a. blanch it) to "set" its green color for pesto that stays remarkably, beautifully, brilliantly green. See details here.