Well-ripened tomatoes don’t last long, whether they’re from the farmer’s market or your own garden. Freezing them is one way to preserve their rich flavor for use later in the year, when flavorless supermarket varieties are all that’s left. Most instructions call for tomatoes to be blanched and peeled before they’re frozen, but you can skip the messy and inconvenient blanching stage if you wish.
Blanching your tomatoes means either dropping them briefly into boiling water, or steaming them for a few minutes. The time spent in the boiling water or steam isn’t long enough to actually cook the tomatoes, but it does two important things. Blanching stops the enzymes in tomatoes that normally cause them to decompose. This helps your tomatoes retain their quality longer in the freezer. The process also loosens the skins, making them easy to remove with your fingers or a paring knife. The skins become tough and leathery after freezing, so that’s a definite plus. However, you can skin tomatoes without blanching.
Preparing Your Tomatoes
Pick out the ripest unblemished tomatoes you can find, and remove the stems. Rinse them thoroughly under cold water and pat them dry. Use a tomato corer or the tip of a paring knife to cut out the stem area and tough, pale section just beneath it. You can peel a tomato with your paring knife by scoring the skin and loosening it with the knife tip; peel the skin off gently with your paring knife. It’s easier to buy a tomato peeler, a device that looks like a vegetable peeler but with thinner, sharper serrated blades. It enables you to peel a ripe tomato just like any other vegetable, though you’ll probably lose some of the juice.
Freezing Your Tomatoes
Once you’ve peeled the tomatoes, you can freeze them either whole, halved or chopped. Bag them in portions that work for your favorite recipes. For example, if your marinara sauce recipe uses a quart of whole tomatoes, freeze that many per bag. Alternatively, halve or chop your tomatoes and squeeze out the seeds and surplus juice. Portion the tomatoes into individual bags or freezer containers, and place them around your freezer in a single layer. They’ll freeze more quickly than if they’re stacked, and the faster they freeze the better texture they’ll have.
Alternatively, you can freeze the tomatoes without peeling them at all. Wash and dry them, and cut out the core under the stem. Freeze the tomatoes on a parchment-lined baking sheet in a single layer, with space between them for the air to circulate. Once they’re frozen, bag them for later use. You can defrost as many tomatoes as you need for a given recipe. Run them briefly under warm water and the skins will simply slide off, just as if they’d been blanched.
References and ResourcesOn Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
National Center for Home Food Preservation: Freezing -- Tomatoes