Yes you can freeze mushrooms, but there are some important things to keep in mind. Mushrooms contain a lot of water, so they will start to become soggy when they're frozen. That means if you want them to have a texture like fresh mushrooms, then you need to blanch them first and dry them well before freezing. - If you're going for the best quality after thawing, it's best to use a vacuum sealer or heavy-duty freezer bags with as much air removed from the bag as possible. - To prevent freezer burn, store your frozen mushrooms at least 3 inches (8 cm) away from any other food or packaging material. - Mushrooms can be frozen for up to 12 months. - You can add these mushrooms to any dish that will be thoroughly cooked (like casseroles). - Alternatively, if you want the mushrooms on the softer side, let them thaw in the fridge until they are soft enough for use.