This article reviews how freezing affects mushrooms, as well as the best ways to freeze them to preserve their flavor and texture as much as possible.
To keep mushrooms longer, you can freeze them. However, it’s important to understand how freezing may affect their quality.
That said, sometimes it’s not possible to use all of the mushrooms you bought before they go bad.
To maximize texture and flavor, mushrooms should ideally be used fresh.
Freezing mushrooms can increase their shelf life and reduce food waste. However, the process may negatively affect their nutrient composition, texture, and flavor.
Fortunately, some pre-freezing preparation methods can help mushrooms maintain their freshness, texture, and nutrients.
Texture can likewise be affected. While you can freeze raw mushrooms, given their high water content, they can become mushy when thawed. This can work for soups, casseroles, or blended dishes, but you may not want squishy mushrooms for other things.
While freezing doesn’t affect the calorie, fiber, or mineral content of foods, it can reduce the content of water-soluble vitamins like riboflavin, niacin, and folate. Keep in mind that fresh produce also loses nutrients over time ( 2 , 3 ).
Over time, frozen produce tends to lose some of its nutritional value. Mushrooms are a good source of nutrients like B vitamins, copper, potassium, and vitamin D ( 1 , 2 , 3 , 4 ).
While you can freeze mushrooms, keep in mind that this can negatively affect their quality.
Most fresh mushrooms last for about 1 week in the refrigerator before they start showing signs of nearing their expiration date, such as becoming soft, brown, or even slimy.
The fresher mushrooms are when you freeze them, the better they’ll keep in the freezer. Fresh mushrooms have a firm texture and pleasant earthy smell. Plus, they’re free of mushy or dark spots.
Sometimes the best place to purchase fresh mushrooms is at your local farmer’s market, but you may also find locally grown mushrooms at your grocery store.
Before freezing mushrooms, brush off any visible dirt. Many people are tempted to wash mushrooms before freezing them, but this tends to make them mushier when cooked.
If you choose to freeze the mushrooms raw, trim their stems and place them in a freezer-safe plastic bag. Squeeze out as much air as you can before sealing the bag and placing it in the freezer.
If you don’t want to freeze raw mushrooms, below are two recommended methods for preparing them prior to freezing.
Steam blanching is a quick cooking process that helps preserve produce before it’s frozen. It works by destroying enzymes that can increase how quickly foods spoil (5).
An added benefit of steam blanching is that it inactivates Listeria and Salmonella, two common foodborne bacteria, improving the safety of the mushrooms prior to freezing them (6).
Furthermore, blanching produce may help preserve nutrients (7, 8).
Blanching times vary depending on the size of the mushroom, so it’s a good idea to either sort them by size or cut them into similar-sized chunks before steaming.
To prevent discoloration during the blanching process, first soak your fresh mushrooms in a mixture comprising 2 cups (480 mL) of water and 1 teaspoon (5 mL) of lemon juice for 5–10 minutes.
Alternatively, you can steam your mushrooms using a mixture of 4 cups (960 mL) of water and 1 teaspoon (5 mL) of lemon juice.
To steam blanch your mushrooms, bring a pot of water to a boil and place a steamer basket inside. Add the mushrooms to the basket and let them steam for 3–5 minutes.
Then, remove the mushrooms and place them immediately into a bath of ice water for the same amount of time that you steamed them. Strain the water, place the mushrooms in airtight, freezer-safe bags, and store them in the freezer.
Sautéing is a method of dry heat cooking that uses a small amount of fat and relatively high temperature to soften and brown food quickly.
Cooking this way without water may prevent the loss of B vitamins. Additionally, cooking with fat may improve the absorption of antioxidants and other plant compounds (9, 10, 11, 12).
In a large skillet, add fresh mushrooms and a small amount of hot oil or butter and bring to medium-high heat. Cook them for approximately 5 minutes, until almost fully cooked. The mushrooms should become tender but not squishy.
Remove your mushrooms from the skillet and place them on a paper towel or plate to cool. Once thoroughly cooled, place them in an airtight, freezer-safe bag and store them in the freezer.
Frozen mushrooms prepped using any of these methods can be used in many ways. They work best if added to dishes that will be cooked rather than eaten cold.
SUMMARYYou can freeze mushrooms raw, or prepare them for freezing by first steam blanching or sautéing them to help preserve qualities like nutrition, flavor, and texture.