Mushrooms are a versatile ingredient that can be used in many dishes. However, they are also quite perishable and will only last 3-7 days when refrigerated. Freezing is a great way to extend the shelf life of mushrooms so you can enjoy them long after purchase. But should you freeze them raw or cook them first? There are pros and cons to each method.
Quick Answers
– It is generally better to freeze mushrooms raw rather than cooked. Raw mushrooms will retain more texture and flavor when thawed.
– Slicing or chopping mushrooms before freezing can help them freeze and thaw more evenly. Leave whole mushrooms intact.
– Blanching or sautéing mushrooms briefly before freezing can help prevent texture changes but is not required.
– Frozen raw mushrooms will last 9-12 months in the freezer before quality starts to decline. Cooked mushrooms only last 2-3 months.
– Thaw frozen mushrooms in the refrigerator or microwave. Do not thaw at room temperature.
– Use thawed mushrooms immediately in recipes rather than refreezing.
Benefits of Freezing Mushrooms Raw
Here are some of the biggest advantages to freezing mushrooms without cooking them first:
- Better texture – Raw mushrooms maintain their original firm, meaty texture much better than cooked mushrooms when frozen and thawed.
- More flavor – The natural umami flavor of raw mushrooms comes through more strongly than in cooked, frozen mushrooms.
- Longer shelf life – Raw frozen mushrooms will keep for 9-12 months in the freezer before quality declines compared to 2-3 months for cooked mushrooms.
- More versatile – Raw frozen mushrooms can be used in any recipe calling for fresh mushrooms without needing to pre-cook them.
- Faster cooking – There’s no need to thaw raw frozen mushrooms. They can go straight into soups, sauces and other dishes to cook.
- Better nutrient retention – Raw mushrooms retain more nutrients like vitamin D, potassium and antioxidants compared to cooked, frozen mushrooms.
Freezing mushrooms raw helps them retain the attributes we all know and love about fresh mushrooms – texture, flavor, nutrients and versatility in cooking. You just get to enjoy them a lot longer!
Potential Drawbacks of Freezing Raw Mushrooms
Freezing raw mushrooms does come with a few potential downsides:
- Water crystals form – The high water content in raw mushrooms can lead to larger ice crystals forming during freezing, damaging cells.
- Oxidation – Enzymatic browning and oxidation may occur over long frozen storage, leading to some discoloration.
- Soft texture – Even with the best methods, some textural changes are inevitable after freezing raw mushrooms, especially the gills.
- No flavor development – The umami taste of mushrooms intensifies with cooking, so frozen raw mushrooms won’t get this benefit.
While none of these drawbacks are dealbreakers, they are worth keeping in mind. Proper freezing methods can help minimize the texture and color changes. And for some uses like casseroles and soups, mushrooms don’t need peak texture anyway.
Benefits of Freezing Cooked Mushrooms
What are the potential perks of blanching, sautéing or otherwise cooking mushrooms before freezing?
- Prevents enzyme activity – Cooking deactivates enzymes that can lead to off flavors during frozen storage.
- Stabilizes texture – Heat can breakdown cell walls leading to less damage from ice crystals forming.
- Intensifies umami – Cooking boosts natural umami compounds in mushrooms like glutamates.
- Saves time later – No need to cook mushrooms when using them straight from the freezer.
- Better color – Less oxidation means frozen cooked mushrooms may have better color retention.
- Kills microbes – Cooking mushrooms destroys any bacteria, yeasts or molds that could grow over long frozen storage.
For recipes like casseroles, soups and sauces where texture isn’t as important, cooked frozen mushrooms can be more convenient to use right out of the freezer. Their developed flavor can be an asset as well.
Potential Drawbacks of Freezing Cooked Mushrooms
What are some of the downsides of freezing pre-cooked mushrooms?
- Mushier texture – Cooked mushrooms almost always get softer during freezing compared to raw mushrooms.
- Loss of fresh flavor – Subtle natural flavors dissipate when mushrooms are cooked then frozen.
- Shorter shelf life – Cooked frozen mushrooms last just 2-3 months before quality suffers compared to 9-12 for raw.
- Less versatility – Cooked mushrooms can only be used in dishes with further cooking.
- Altered appearance – Blanching and sautéing can change the look of mushrooms, especially the gills and shape.
- Time-consuming – Having to cook mushrooms before freezing adds extra time and effort.
For any recipes where the fresh texture and flavor of mushrooms is critical, cooking them before freezing can negatively impact the finished results. Their shortened shelf life is also a major downside.
Best Methods for Freezing Mushrooms Raw
To freeze raw mushrooms at home with the best results, follow these steps:
- Buy fresh, high-quality mushrooms free of blemishes at their peak ripeness.
- Clean the mushrooms gently by wiping with a damp cloth or paper towel. Avoid soaking them.
- Slice, chop or leave mushrooms whole depending on intended use. Uniform sizing helps freezing.
- Arrange mushrooms in a single layer on a parchment-lined baking sheet.
- Place the baking sheet in the freezer until mushrooms are completely frozen, about 2 hours.
- Transfer frozen mushrooms to freezer bags or airtight containers, removing as much air as possible.
- Return to freezer immediately at 0°F or below for best quality retention.
- Use within 9-12 months for peak flavor and texture.
Slicing mushrooms encourages faster, more even freezing. Leaving mushrooms whole works best for varieties with caps like buttons and portobellos. Always freeze mushrooms in a single layer first to prevent clumping.
Blanching Mushrooms Before Freezing
Some sources recommend blanching or steaming mushrooms for 1-2 minutes before freezing raw. This process stops enzyme activity and helps retain color. However, it can result in more mushiness after thawing. Blanching is optional and not critical for freezing mushrooms properly.
Additional Tips
- Avoid freezing poor quality or old mushrooms, as freezing can’t improve food.
- Don’t rinse or soak mushrooms before freezing, as they will absorb excess water.
- Use freezer bags or containers – don’t just wrap mushrooms in plastic wrap or foil.
- Press out all air and seal packages well to prevent freezer burn.
- Store mushrooms below 0°F for longest shelf life and quality retention.
Best Methods for Freezing Cooked Mushrooms
For cooked mushrooms with the best final results, follow these recommendations:
- Start with high-quality fresh mushrooms without blemishes or bruises.
- Clean gently with a damp cloth or paper towel.
- Slice, chop or quarter mushrooms depending on the recipe needs.
- Cook mushrooms by sautéing in olive oil or butter, microwaving, or blanching until just tender.
- Drain or pat off any excess moisture after cooking.
- Spread in a single layer on a baking sheet and freeze until solid.
- Transfer to airtight freezer containers or bags, removing air.
- Return to freezer at 0°F or below.
- Use within 2-3 months for best flavor and quality.
Mushrooms can also be frozen after cooking in or for a specific recipe like casseroles, soups or sauces. Just cool the finished dish rapidly before freezing.
Microwaving and Blanching
If sautéing isn’t practical, mushrooms can be cooked in the microwave or by steaming or blanching. Cook just until tender-crisp – 1-2 minutes for sliced mushrooms and a bit longer for quarters or pieces.
Additional Tips
- Pat mushrooms very dry after cooking to remove excess moisture before freezing.
- Undercook mushrooms slightly before freezing as they’ll finish cooking when reheated.
- Use cooked frozen mushrooms within 2-3 months for best quality and texture.
- Thaw cooked mushrooms in the refrigerator before use to prevent further moisture loss.
How to Thaw Frozen Mushrooms
To safely thaw frozen mushrooms and retain quality, use one of these methods:
- Refrigerator thawing – Place frozen mushrooms in the refrigerator overnight or up to 1-2 days ahead. Best for raw mushrooms.
- Cold water method – Seal mushrooms in a bag and submerge in cold tap water, changing water every 30 minutes. Takes 2-3 hours for a 1 lb bag.
- Microwave thawing – Microwave frozen mushrooms on defrost setting or very low power until thawed. Best for cooked mushrooms.
- As part of cooking – Raw and cooked frozen mushrooms can be added directly to hot soups, sauces and casseroles to thaw and cook.
Always cook thawed mushrooms immediately rather than trying to refreeze them. Mushrooms are very prone to bacterial growth at temperatures above 40°F.
Storing Thawed Mushrooms
Like fresh mushrooms, thawed frozen mushrooms have a very short shelf life. Use thawed mushrooms within:
- 1-2 days in the refrigerator if raw
- 3-4 days in the refrigerator if cooked
- 6 months in the freezer if incorporated into a cooked dish
The sooner thawed mushrooms are eaten, the better their texture and flavor will be. Cooked thawed mushrooms can be frozen again if used in casseroles, soups or other dishes.
Substituting Fresh for Frozen Mushrooms
In most recipes, frozen mushrooms can be used in place of fresh with some adjustments:
| Fresh Mushrooms | Frozen Mushrooms |
|---|---|
| 1 lb fresh mushrooms | 10 oz frozen mushrooms |
| No added liquid | May need extra thickener like flour to account for moisture released |
| Saute over high heat | Saute over medium heat so mushrooms fully thaw |
| Cook 5-8 minutes | Cook 3-4 minutes just until heated through |
Reduce any cooked frozen mushrooms to remove excess moisture. And allow some extra cooking time for frozen mushrooms to thaw and heat through.
Conclusion
Freezing is an excellent way to preserve mushrooms for 9-12 months while retaining their fresh mushroom flavor, texture and nutrients. For best results overall, it is generally better to freeze mushrooms raw rather than cooked. Raw frozen mushrooms retain more of their original firm, meaty texture and subtle earthy flavors compared to mushrooms that are cooked before freezing. They also have a longer freezer shelf life.
However, cooked frozen mushrooms can be more convenient to use straight from the freezer in some instances. Pre-cooking intensifies the umami taste of mushrooms and stops enzyme activity that could lead to off flavors over months of freezing. Cooked mushrooms are best for uses like casseroles, soups and sauces where perfect texture isn’t necessary.
With either raw or cooked freezing methods, start with fresh, high-quality mushrooms. Portion, spread in a single layer on trays, freeze solid, and transfer to airtight bags or containers removing excess air. Thaw slowly in the refrigerator for raw mushrooms or microwave for cooked. Use thawed mushrooms as soon as possible for the freshest flavor and texture.