How to Freeze Mushrooms Without Them Turning Slimy

If you have ever tried to throw raw mushrooms into a ziplock bag and freeze them, you know the result: a disgusting, slimy, brown mush. Mushrooms are mostly water. When that water freezes and expands, it bursts the delicate cell walls.

To freeze mushrooms effectively, you must cook them first.

The Steam or Sauté Rule

You need to remove some moisture and collapse the cell structure with heat before freezing.

1. Sauté (Best for Flavor): Slice the mushrooms and sauté them in a little oil or butter until they release their liquid and brown slightly.
2. Steam (Best for Neutral Flavor): Steam whole or sliced mushrooms for 3-5 minutes, then plunge into ice water.

Freezing

Once cooked and cooled:

• Spread them on a tray to flash freeze.
• Once hard, bag them up.

Using Frozen Mushrooms

Since they are already cooked, you don't need to thaw them! Toss the frozen slices directly into your omelet, pasta sauce, or beef bourguignon. They add instant umami without the prep work.