When it comes to freezing mushrooms, there are two main options – freeze them raw or cook them first before freezing. Both methods have their pros and cons, so deciding which is ‘better’ depends on your priorities when freezing mushrooms. In this comprehensive guide, we’ll look at the key factors to consider and help you determine whether raw or cooked is best for your needs.
Quick Answer
For most purposes, it is better to freeze mushrooms raw rather than cooked. Raw mushrooms retain more texture and flavor when thawed. The cell walls in raw mushrooms remain largely intact during freezing, so they avoid becoming mushy or waterlogged. Raw mushrooms are also more versatile – they can be used in any recipe after thawing. The only exceptions are if you need to freeze mushrooms that will be used exclusively for cooked dishes where texture isn’t important. In that case, cooking them first can help them last longer in the freezer.
Factors to Consider When Freezing Mushrooms
Here are the main variables that impact the freezing process for mushrooms:
- Texture – Raw mushrooms retain more of their original crispiness and firmness.
- Flavor – Raw mushrooms maintain more of their natural umami taste.
- Usability – Raw mushrooms can be used without cooking after thawing.
- Shelf life – Cooked mushrooms may last slightly longer in the freezer.
- Convenience – Raw mushrooms require no prep before freezing.
- Recipe needs – Cooked mushrooms are suitable for casseroles and other dishes with long cooking times.
Let’s explore each of these factors in more detail.
Texture
Freezing causes damage to the cell structure of mushrooms. When frozen raw, the cell walls rupture less than if the mushrooms are cooked first. This results in a better texture – mushrooms frozen raw retain more of their original crunchy, crisp consistency when thawed.
On the other hand, cooking mushrooms before freezing breaks down pectin and plant cell walls. The high water content is released, resulting in a softer, mushier texture after thawing.
Flavor
Along with changes in texture, freezing and thawing degrades the flavor of mushrooms. This flavor loss is minimized by freezing mushrooms raw. The natural umami taste remains more intact, versus cooked mushrooms which tend to taste more watered down.
Usability
Raw frozen mushrooms can be used for any recipe after thawing – soups, salads, sandwiches, pizzas, breakfasts, etc. Their texture and flavor is suitable for quick cooking methods like sauteing, stir frying or dropping into soups.
Pre-cooked mushrooms are limited in their post-thaw uses. As they are already soft, they are only suitable for dishes with longer cooking times like casseroles or mushroom pie. They would become overcooked and mushy in quick recipes.
Shelf Life
Cooked mushrooms may potentially last a bit longer in the freezer compared to raw. Heat from cooking deactivates enzymes that can lead to faster deterioration during freezing. Cooked mushrooms also have less liquid, so there is less risk of ice crystals forming that can damage the cell structure.
However, for most homemade freezer storage times, the shelf life difference is negligible. Properly frozen raw mushrooms hold up very well for 6-12 months.
Convenience
Freezing mushrooms raw requires no prep work besides cleaning and slicing. You can go straight from the grocery store to the freezer bag.
Cooking mushrooms before freezing takes more time and effort. You also have to let them cool completely before freezing, adding more time.
Recipe Needs
If you plan to only use your frozen mushrooms for long-cooked recipes like casseroles, soups, sauces or mushroom pie fillings, then cooking them first is reasonable. Since they’ll be cooked again anyway, the lesser texture and flavor after thawing won’t matter as much.
But for any recipes requiring quick cooking, sauteing, or no cooking, raw frozen mushrooms are always preferable.
Optimal Methods for Freezing Mushrooms Raw
To maximize quality when freezing mushrooms raw, follow these tips:
- Clean mushrooms thoroughly – wipe with a damp cloth or paper towel to remove dirt and debris.
- Slice mushrooms to desired size if needed for recipes. Uniform sizing helps mushrooms freeze evenly.
- Blanch for 30 seconds (optional) – quick dip in boiling water helps preserve color and texture.
- Pat dry – remove excess moisture to prevent ice crystals forming during freezing.
- Spread in single layer on tray and freeze initially, then pack into bags.
- Exclude as much air as possible and use freezer bags or airtight containers.
- Freeze quickly at 0°F or below. Use fast blast or flash freezing if possible.
- Avoid refreezing mushrooms after thawing.
Let’s look at why each step contributes to better results:
Cleaning
Give mushrooms a quick wipe, rub or rinse to remove any visible soil, debris or grit. This prevents frost burn spots from dirt freezing onto the mushroom surface during freezing. Any dirt will also degrade quality over the long freezer storage time.
Slicing
Uniformly sizing your mushrooms allows them to freeze solidly all the way through. Whole mushrooms freeze slower in the center, leading to larger ice crystals. Quicker freezing equals smaller ice crystals for less cell damage.
Common slicing options include:
- Button or small mushrooms – keep whole or slice in half.
- Cremini or portobello – slice 1/4 to 1/2 inch thick.
- Shiitake – remove stems and slice caps 1/4 inch thick.
- Oyster – remove whole stems and slice caps crosswise.
Blanching (Optional)
A quick 30 second dip in boiling water helps set the color and firm up the texture. Pat dry thoroughly before freezing. Blanching is optional but can improve post-thaw quality.
Patting Dry
Remove as much moisture as possible from the surface of mushrooms before packing for freezing. Moisture leads to more ice crystal formation and structural damage during freezing. Dry thoroughly with paper towels or a clean dish cloth.
Single Layer Freezing
Spreading mushrooms out on a sheet pan or tray initially helps them freeze faster than stacking together in a bag or container. Faster freezing equals smaller ice crystals and better texture retention. Freeze in a single layer for 1-2 hours before packing into freezer bags or containers.
Minimizing Air Exposure
Exclude as much air as possible when packing mushrooms for the freezer. Use freezer bags and the water immersion or vacuum seal method. Or use rigid airtight containers, pressing out air before sealing. Trapped air causes freezer burn over time.
Fast Freezing
Get mushrooms into the freezer as quickly as possible, at 0°F or ideally -10° to -20°F or below. A blast chiller is optimal but the coldest home freezer will work. Slow freezing in a warmer freezer leads to larger ice crystals.
Avoid Refreezing
Only freeze mushrooms once – don’t refreeze after thawing. The ice crystals damage the cell structure, and refreezing aggravates this deterioration of texture and flavor.
Methods for Freezing Cooked Mushrooms
If you do opt to freeze your mushrooms cooked, follow these guidelines:
- Clean mushrooms thoroughly first.
- Slice or leave whole depending on recipe needs.
- Saute, simmer or roast until tender – avoid overcooking.
- Drain any excess liquid, pat dry.
- Spread on tray and cool completely before freezing.
- Pack into freezer bags, excluding air.
- Freeze at 0°F or below as quickly as possible.
Freezing mushrooms cooked is simpler overall. But take care not to overcook them prior to freezing, as they’ll become even softer after thawing. Cook just until tender but not mushy.
Thawing Frozen Mushrooms
Both raw and cooked frozen mushrooms should be thawed in the refrigerator overnight when possible. Microwaving or quick thawing leads to more moisture loss.
Whether frozen raw or cooked, mushrooms will deteriorate in texture, flavor and appearance over time in the freezer. Eat within 6 months for best quality.
Best Mushroom Varieties for Freezing
Button, cremini, portobello and white mushrooms freeze very well raw or cooked. Their compact structure resists damage from ice crystals. Shiitake and oyster mushrooms also freeze decently when done carefully.
More delicate mushrooms like enoki, chanterelle and porcini don’t hold up as well to freezing. Avoid freezing them when possible.
Conclusion
Freezing mushrooms raw is the best option for preserving flavor, texture and versatility. The exception is if you only plan to use the mushrooms in long-cooked dishes, in which case cooking them first is acceptable. Make sure to pack raw mushrooms for the freezer in single layers for fast freezing, and minimize air exposure. Handle them gently during thawing and use within 6-12 months.
Following these tips, you can enjoy delicious mushrooms straight from your freezer any time of year!
References
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