One way to preserve some fruits and vegetables to use later is to freeze them. Most vegetables survive the freezing process better if they are blanched before they are frozen. Blanching is a term for the process of boiling for a short amount of time and then placing in ice water to stop the cooking process. Blanching some vegetables preserves their flavor, color and texture. The cooking times are different for various vegetables, it is advised to consult a food preservation guide or website for information on the different vegetables.
There are different ways to blanch vegetables, water blanching, steam blanching and microwave blanching. One of the most used is water blanching. Bring a large pot of water to a rapid boil over high heat. While you are waiting for the water to heat, fill a medium bowl about three fourths full with ice and add enough cold water to cover the ice. Cut the vegetables into bite size and add to the boiling water in small batches. It is important to blanch in small batches so the water maintains a boil. Once the vegetables are cooked the recommended amount of time, remove with a slotted spoon and put immediately into the ice water. As soon as they are no longer warm, you can remove them from the ice water.
They can be dried off and packaged in whatever size servings you prefer. Some items you may want to flash freeze on a baking tray before freezing so they do not freeze into a ball. If they are frozen on a tray before freezing it will be easier to remove a certain amount without needing to thaw the entire package.
Steam blanching is only recommended for a few certain vegetables such as broccoli, pumpkin, sweet potatoes and winter squash. Microwave blanching may not be as effective as the other two methods.
Some items that can be frozen without blanching are onions, peppers, raw tomatoes and some berries. They can be washed and cut into small pieces and frozen. They may not have the same crispness as they had, but can be used in casseroles and other meals where they are cooked.
Some vegetables such as lettuce do not survive freezing at all. It is best to use these while they are fresh. There is no way to preserve lettuce to use in the future.
Blanching is a way to preserve some vegetables so that they retain more of their color, flavor and texture after they are frozen.