The key to saving your fresh herbs until you need them again is simple. You just need a freezer and a little olive oil to keep them delicious for six months, according to Rodale’s Organic Life.
The unique flavors of fresh herbs come from the oils in the leaves, so you want to keep them from drying out. To do so, you can mix them into a paste with a fat like olive oil or butter. Stick the oily herbs in the freezer in a Ziplock bag and they will be good to go for up to six months—far longer than they’d last wrapped in a wet paper towel in your fridge. They’ll keep their flavor and texture far better in oil than they would frozen on their own or in water.
Ideally, you should mix the leaves of your fresh herbs in a food processor with your oil or butter. Organic Life’s Laurie Constantino recommends using 1/3 cup of olive oil for every 2 cups of leaves, or, for butter, one unsalted stick for every 2 to 4 tablespoons of leaves. Either way, it should come out as a chunky herb paste, rather than an oily soup.
Then, just freeze the mixture in a flat, thin layer inside a plastic bag. Once frozen, you can break off chunks of the icy herb concoction and stick them directly into whatever you’re cooking.
[h/t Rodale’s Organic Life]