Wash and remove the stem core. Tomatoes can be frozen whole (skin on), halved, chopped, or puréed. If you want to remove skins before cooking, blanch whole tomatoes for 30 seconds, ice bath, and slip the skins off before freezing.
Whole (easiest method): Wash, core, and place whole tomatoes on a sheet pan. Freeze solid, then transfer to freezer bags. When you need them, run a frozen tomato under warm water for a few seconds and the skin slips right off.
Chopped or crushed: Core and chop or crush tomatoes. Pack into rigid containers or freezer bags with ½ inch headspace. Flat-pack bags for efficient stacking.
Sauce or paste: Cook tomatoes down into sauce, cool completely, and freeze in measured portions. Ice cube trays work well for tomato paste — freeze in cubes, then bag the cubes.
Roasted: Halve tomatoes, drizzle with olive oil, roast at 400°F (200°C) until concentrated and caramelized. Cool, then pack into containers with their juices. Frozen roasted tomatoes add incredible depth to winter sauces and soups.
2 to 3 months for raw whole or chopped. 6 to 8 months for sauce, paste, or roasted.
For sauces and soups: add frozen directly to the pot. For recipes needing skinned tomatoes: run frozen tomatoes under warm water to slip off skins, then chop while still partially frozen.