Leafy greens such as spinach, kale and chard need to be briefly cooked before they are frozen. Skip this step and you'll end up with black goo when you defrost your greens (yuck). The brief cooking halts an enzymatic process that would otherwise make the leaves continue to decay even in the freezer. Blanching is one of the simplest brief cooking methods and ensures your greens will emerge from the freezer with bright color and excellent flavor and texture.
1. Bring a large pot of water to a boil. While you are waiting for the water to boil, wash the leafy greens by swishing them around in a sink full of water.
2. Strip away and discard (compost) tough leaf midribs and stems. Note: chard and bok choy have thick but tender and delicious leaf stalks, but they do not freeze well. Blanch and freeze the green parts of these vegetables and reserve the leaf stalks to use fresh in a recipe.
3. Stir your leafy greens into a pot of boiling water. Let blanch in the boiling water for 1 minute.
4. Drain the blanched greens in a colander. Immediately run under cold water to stop the cooking process. Alternatively, plunge the blanched greens into a bowl of ice water.
5. Squeeze the blanched and chilled greens hard to get out as much of the watery content as possible. Squeeze hard. You want to end up with a clump of compressed greens.
6. Chop the clump of blanched greens.
7. Pack the blanched, chopped leafy greens into freezer bags or containers. Label with the name of the vegetable and the date. Freeze.
