How to freeze vegetables

Published: 23 November 2015

What you’ll need

You don’t have to buy fancy equipment to portion off foods in the freezer. Zip lock bags and recycled containers such as plastic* peanut butter jars (big and small), margarine tubs and ice cream containers all work well.  If you want smaller portions, freezing vegetables in an ice cube tray can work too (and then transfer frozen cubes to a container).

In the method below, we use a baking tray, but anything similarly flat will do.

1. Cut the vegetables into pieces. Think about how you'll most likely be using the vegetables later on, when you chop them up. For soups and casseroles, small bite-sized pieces are great. If you’ll use them grated, just grate and freeze in a thin layer (best done in the portions you’ll use e.g. one cup per tray).
2. Raw vegetables should be blanched (quick boil) before freezing. This helps kill the enzymes that can spoil frozen foods. Bring a large pot of water to a rolling boil. Fill a large bowl with ice water, settle a strainer inside, and place this near the stove. Blanch (boil) vegetables for 45 to 60 seconds and transfer to the ice water bath to cool. When done, the vegetables should still be crisp-tender and taste raw in the middle.
3. Scoop out of the water and arrange in a single layer on a baking sheet (or similar tray) lined with a silicon baking mat (optional). Pat the vegetables dry with a clean tea towel; you won't get them completely dry, but even patting them a little bit helps prevent puddles and big ice crystals from forming.
4. Freeze until solid. Put the whole baking tray in the freezer to freeze overnight.
5. Lift the corners of the baking mat to dislodge the frozen vegetables and transfer to freezer bags or containers.
6. Label and date the containers. Most vegetables stored correctly will keep for 6 months.

As an alternative to blanching, there may be some vegetables you want to cook completely before freezing. Some examples are mashed potato/kumara/pumpkin, or chopped and cooked courgette/eggplant/tomato. This can be a great way to have parts of a recipe prepared in advance, as long as you freeze it in the portions you’ll need.

You can also make your own baby mash by having cubes of various cooked, frozen vegetables on hand to defrost as needed. For example a few cubes of mashed potato mixed with a cube of eggplant and a cube of pumpkin per child. Having them in small cubes makes it easier to reheat in the microwave.

Remember, it’s best not to freeze vegetables with a high water content such as lettuce, celery and cucumber. The water in these expands and makes the vegetables go limp and mushy.

*Safety Note: Glass containers can shatter by being frozen.