You certainly can freeze fruit to preserve it, and a number of freezing techniques can be used, depending on how you want to use the fruit, and how long it will remain frozen. In fact, in terms of nutritional value, freezing is better than canning, because freezing arrests the fruit at peak ripeness, preserving the vitamins and minerals which make fruit so nutritious. Frozen fruit can be used in all sorts of ways, from smoothies to pies, and it can be especially refreshing in the winter, when your access to fruit might be limited otherwise.
If you want to freeze fruit, it is best to use fruit which is at the peak of its ripeness. The fruit should be washed before freezing and allowed to dry on a towel, minimizing the amount of moisture which will enter the freezer with the fruit. Many people like to chop fruit after washing so that it is ready to use, removing rinds, pits, and other unwanted materials. This also cuts down on the amount of space needed to store the fruit. Once the fruit is prepared, rapid freezing is key, because slow freezing creates big ice crystals which will damage the cell walls of the fruit.
It's a good idea to make lots of room in the freezer to freeze fruit, allowing air to circulate all the way around the fruit while it freezes. You may also want to turn the freezer down a bit to increase the speed at which the fruit freezes.
Tray freezing is a method suitable for small fruits like berries, cherries, and so forth. In this type of freezing, the fruit is laid out on a tray, allowed to freeze, and then bagged or boxed for storage. This reduces the buildup of ice in the container, and freezes each fruit individually so that it can be removed individually. For larger fruits and cut fruits, you will need to pack to freeze.
In a basic dry pack to freeze fruit, you just stick the fruit in a plastic bag or freezer container, squeeze it to get the air out, leave a little bit of headroom so that the fruit can expand, and stick the fruit in the freezer. To reduce browning and preserve the nutrients, you can squeeze lemon juice over the fruit and mix before freezing. In sugar and syrup packing, you mix the fruit with sugar or syrup, which acts as a preservative to keep the fruit in good condition in the freezer. You can also puree fruit for freezing, a technique which works really well for fruits which have peaked.
When you freeze fruit, the freezer life is around eight to 12 months, with syrup and sugar packed fruits faring better on the 12 month end of the spectrum than dry frozen fruit. To use the frozen fruit, you can move it into the fridge to thaw, or run warm water over the fruit in a sieve, allowing the fruit to come quickly to room temperature. Frozen fruit can be added to recipes, blended in smoothies, used as a pie base, made into jams and jellies, and thawed and eaten out of hand like fresh fruit, among many other things.
