Things You'll Need
Oil or water
Ice cube tray(s)
Fresh basil offers a vibrant flavor that can enhance dishes ranging from pasta sauce to pizza. Pesto, a blend generally containing finely chopped basil leaves, olive oil, nuts, garlic, salt and cheese, also works with a wide variety of dishes; you can, for example, toss spaghetti with this rich green sauce, add it to mashed potatoes or simply spread it on a piece of bread for a quick snack. Despite their rather different consistencies, you can freeze basil leaves and pesto in almost exactly the same way.
Prepare the basil or pesto you wish to freeze. Chop any fresh basil you wish to freeze into very fine pieces, then place it with a bowl. Add just enough oil or water to make a thick paste. Stir constantly as you add the liquid to help avoid adding too much. Make the pesto as normal, but leave out any cheese in the recipe. Cheese does not freeze well, so you should leave it out for now and add it after thawing the pesto just before you wish to serve it.
Spoon the pesto or your fresh basil paste into an ice cube tray. Fill each hole, but try not to spill too much onto the sections around the holes. If you are freezing both pesto and chopped basil, keep track of which hole contains which. Ideally, use a separate ice cube tray for each so you do not confuse the two.
Place the ice cube tray or trays into your freezer. Leave them here until the pesto or basil paste has frozen solidly enough to handle easily.
Remove the frozen basil or pesto cubes from the ice cube tray and place them into freezer-safe bags. If you froze both basil paste and pesto cubes, put them into separate bags so you that know which is which when you are ready to use them. Place the bags into the freezer and use within six months.
Rinse your fresh basil thoroughly before freezing it or making it into pesto. Thaw pesto at room temperature. Thaw basil at room temperature, or add the frozen cube to a hot recipe and allow it to melt.