A relatively non-traditional way to preserve basil is to freeze it. In fact, this works with several herbs. The trick is to keep the leaves from getting frostbitten in the freezer, which industry has accomplished through vacuum sealed freeze drying. In the home kitchen, however, that kind of equipment isn’t available.
You can still freeze basil and use it in recipes throughout the year, no matter the season. Many of those who prefer freezing say that the process means you preserve more flavor in your leaves than you do through drying.
There are several ways to freeze basil leaves. Here we’ll show you two that are the easiest to do.
First, you need to harvest your basil. There are different harvest methods for basil. You can harvest all season long to increase production from a basil plant. For the purposes of preserving, a lot of home gardeners will do a large harvest towards the end of the gardening season.
Most gardeners do this in the fall before the weather changes in order to keep their leaves from getting ruined in the frost. You can cut the leaves with shears or scissors as you would as if you were about to use it fresh for cooking. Or, harvest by cutting near the plant’s base at the soil level to remove the leaves in clusters.
Once you’ve done so, wash the leaves in ambient-temperature water (so they don’t curl in shock) and let dry.
Freezing Basil Leaves
This requires little in the way of tools or supplies. After picking the basil leaves, clean them thoroughly and let them completely dry on paper towels or cheese cloth. After they’ve dried (might take an hour or so), either cut off the stems and chop the leaves into bits or leave them whole to preserve the entire basil leaf.
Place into a sealed plastic container (Glad, Tupperware, etc.) in layers, with a paper towel on the bottom and between each layer of leaves or single layer of chopped leaves. Fill the container to overflowing, putting a final paper towel on top. Crush the leaves down as you press the lid into place. Then “burp” the container and place in the freezer. Remove after about three hours and burp the lid again, getting as much air as possible out of the container.
When ready to use, remove the paper towel layer (or layers) you need and replace the lid, burping and putting back into the freezer. You can use freezer bags in place of a plastic container and squeeze the air out, keeping the bag flat.
Basil and Olive Oil Cubes
Another method is to make ice cubes from basil and olive oil. Using an ice tray or styrofoam egg carton to create ice cubes (in a way). First, chop the basil leaves as above, discarding the stems. Then put chopped basil into each tray cavity, usually about 1/2 or 1 tablespoon. Next, fill each section with olive oil (your choice extra virgin or raw). Place in the freezer and let it freeze.
When you’re ready to use it, just pull out one or more cubes and throw into a pan, soup, cooking pasta dish, etc. The olive oil will melt quickly, letting the basil loose into your recipe. This method saves time in the kitchen when cooking. The olive oil for frying or pan coating is immediately available along with the basil you’re going to use anyway without measuring or chopping.
Keep in mind pesto can be preserved by freezing in ice cube trays, too!
Want to learn more about freezing basil?
Frozen Basil Butter Recipe from Ohio State University Extension
Harvesting and Preserving Herbs for the Home Gardener from North Carolina Cooperative Extension Service