Freezing is the easiest way of keeping garden tomatoes through the winter. Freezing tomatoes can be as easy putting a washed tomato in a freezer-safe container and putting it in the freezer. If you want to get a little more sophisticated than that, you can peel, seed, core and even cook your tomatoes before freezing them. All of these things, as well as blanching the tomatoes, are optional.
The simplest way to freeze tomatoes is to wash them, remove the stem, then place them on a baking sheet with a little space around each tomato. Put the baking sheet in the freezer until the tomatoes are thoroughly frozen. Then remove them from the sheet and seal them into a freezer-safe, zipper-locking bag. Then you can pull out as many tomatoes as you need for a recipe, sealing the rest and keeping them in the freezer for future use.
Some people prefer to peel their tomatoes before freezing because the peels can get a little tough when they freeze. The pulp of the tomatoes freezes just as well with the peels as without. if you freeze the tomatoes whole, you can just strip off the skin before you cook the tomato. If you chop the tomatoes, you can't remove the skin after freezing. A common way of peeling tomatoes before freezing is to blanch the tomato for about a minute in boiling water. Cool the tomatoes immediately in ice water. The skins will slip right off.
Blanching and Enzymes
Blanching, however, destroys enzymes in the tomatoes. Enzymes help ripen the tomato, but they also help break down and rot the tomato when it is over-ripe. Freezing slows down these enzymes but does not destroy them. The advantage of destroying the enzymes is to slow down the tomato's deterioration. Destroying the enzymes slows down the deterioration process, allowing the tomatoes to be kept in the freezer longer. If you wish to keep the enzymes, something that is only an issue if you plan to use the tomatoes without cooking after thawing them, you should freeze the tomatoes without blanching them. Be aware, however, that your tomatoes might not keep as long as blanched tomatoes.
Peeling Without Blanching
Blanching makes peeling tomatoes easier, but you can peel a tomato raw. One option is to use a sharp paring knife and a lot of patience. Another option is a tomato peeler, a tool specially designed for peeling soft fruit like tomatoes and kiwis. These peelers typically have two blades. The blades are sharper and thinner than potato peelers. Firm-fleshed tomato varieties like Roma and pear tomatoes are easier to peel without blanching than beefsteak varieties.