Fresh herbs: The two best ways to preserve them for the winter

By Susan Belsinger
Special to The Washington Post
Tuesday, August 24, 2010; 11:27 AM

The delights of gardening are rewarding at every phase, from witnessing the miracle of sprouting seeds to gathering the fruits of our labor. Later in the season, as the plants mature and produce abundant leaves and flowers, I find a sort of reverence in my first harvests. There is nothing like tasting the first ripe tomato or making a batch of the season's first pesto, grinding it together when the basil is at its finest.

Which, of course, is right now. Basil and other herbs reach their peak of flavor and essential oil production in summer. That means that if you want to experience them in the winter, when you can't gather herbs fresh from the garden, you must preserve the bounty.

But how?

For texture and flavor, I prefer to dry the woody-stemmed perennials such as rosemary, sage and thyme. I also sometimes dry basil, fragrant lemon herbs and mints for use in the kitchen year-round, even though I know that they tend to lose their bright bouquet when dried. Herbs such as tarragon lose their flavor when dried and are better preserved in vinegar.

Generally, freezing most herbs does not yield great results. When you freeze herb leaves in water, the cellular structure breaks down and the leaves turn mushy and dark. Ice crystals often form on the more tender-leaved herbs, making them watery after a month or so in the freezer.

But that doesn't mean you should avoid the freezer entirely. My favorite way to preserve herbs involves chopping them, then combining them with a little oil to make an aromatic paste, which freezes beautifully. To me, it's one of the simplest ways to capture herbal flavor.

I have been preparing these aromatic pastes for about 20 years. The method is good for preserving herbs for cooking (baking, soups or sauces) and for turning the paste into pesto or salsa verde when I just have to have them out of season. This method helps them to better retain their fragrance and flavor than just about any other way I've tried.

When preparing pastes for savory dishes, I use extra-virgin olive oil. If I want to make an aromatic paste with the lemon herbs, the mints or even monarda - which will probably be used for baked goods such as cakes, muffins, breads or cookies - I use a good-quality nut or seed oil such as sunflower.

My second-favorite way to preserve herbs involves making syrups, wonderful flavor essences that can be added in place of the liquid in cakes, pie fillings and all types of baked goods. Brushing lemon verbena syrup on warm lemon poppyseed muffins or a poundcake elevates them to another level, intensifying their aroma and taste. These inspired syrups are delightful on all kinds of fruits and fruit salads, used in beverages, and to make sorbets.

Make these when you have fresh herbs in abundance, and their flavor and perfume will bring a brightness to fruits, cocktails and desserts. Like the herb pastes, they keep best in the freezer, lasting for up to nine months - or until the next season begins.


Avoid the Wintertime Pesto Blues

Basil Paste

Fragrant Herb Syrup

Fruit Salad With Mint

Ginger Syrup

Belsinger is a culinary herbalist, educator and author who lives in Brookeville. You can find more herbal information on her Web site

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