Whether you buy mushrooms in bulk or find yourself with a bunch of leftovers [1] from a single package (the joys of cooking for one!), you probably don't want the veggies (or any of your groceries) to go to waste. So, can you stick them in the freezer? Katie Heil, CP-FS, a certified professional in food safety at StateFoodSafety [2] says you sure can, but they can't be uncooked.
According to the National Centre for Home Food Preservation, mushrooms should be partially cooked before freezing [3] to guarantee they stay fresh, so you have to decide whether you would like to steam or fry them before setting storing them in the freezer for later use or consumption. These are Heil's suggested steps to follow:
- Wash the mushrooms in cold water and trim off the ends. Check the mushrooms for any spots or signs of decay so your frozen batch is as fresh as it can be pre-cooking.
- Quarter any mushrooms larger than 1 inch.
- Choose your preparation:
- To steam: Mix 1 teaspoon of lemon juice in 1 pint of water and soak the mushrooms in the solution for five minutes. The citric acid will help the mushrooms retain their colour in the freezer. Steam quartered mushrooms for 2 minutes — if the recipe you plan to use these on in the future requires whole mushrooms, steam them for 5 minutes. Cool them quickly with an ice bath, and drain the water. Package the mushrooms in a sealed, airtight container and freeze.
- To Fry: Fry mushrooms in margarine or butter until almost done. Cool them quickly and package them in a sealed, airtight container before freezing [4].
Following these steps will keep mushrooms fresh, but it is important to note that freezing may alter the mushroom's colour and in some cases flavour. "Storing mushrooms at 0 °F or lower will prevent microbial growth, but freezing might alter any food's texture [5]," says Heil, adding that you should plan to use your frozen mushrooms within eight to 12 months — when you're ready for that, just put them in the fridge until they've thawed.