Mushrooms: Drying Out And Preservation Techniques

Mushrooms are a popular food item with a highly seasonal availability, typically fruiting in spring and autumn. To enjoy mushrooms all year round, it is necessary to preserve them, and the best way to do this is by drying them. There are several methods to dry mushrooms, including air-drying, using a dehydrator, or an oven. Air-drying involves placing mushrooms in a well-ventilated area with good airflow, and allowing them to dry for about a week. Using a dehydrator is a more expensive option, but it is a worthy investment for those who plan on drying mushrooms regularly. The oven method requires placing the mushrooms on a baking sheet and cooking for an hour, repeating the process until they are dry. Dried mushrooms can be stored in airtight containers and used in recipes by reconstituting them in hot water or broth.

Air drying

Preparation

Start with fresh mushrooms, as this method will not work with mushrooms past their prime. Wipe them clean with a lightly dampened towel, but do not wash them under running water. If you wish, you can slice the mushrooms into 1/2-inch pieces or cut them in half, depending on their shape.

Air-drying Process

Place the mushrooms in an open container that allows good airflow underneath them. A mesh colander or a baking rack set on a baking sheet works well for this purpose. Ensure the mushrooms are not overcrowded and are not stacked on top of each other.

Choose a well-ventilated area with a ready supply of fresh air and, if possible, sunlight. A room with ample sunlight, a flat roof, or a windowsill can be ideal, as long as it is protected from moisture, insects, and animals.

Let the mushrooms air-dry for 7-10 days, or until they do not give when squeezed and feel like little rocks. The drying time may vary depending on humidity levels and the size of the mushrooms. If you live in a humid place, consider partially drying the mushrooms in the oven first and then allowing them to finish air-drying.

Storage

Once the mushrooms are completely dry, they should be stored in an airtight container. Properly dried and stored mushrooms can last up to a year or even longer. However, be cautious of any moisture infiltration, as it can cause the mushrooms to develop mold.

Air-drying mushrooms is a simple and effective method of preservation that does not require any special equipment. By following these steps, you can successfully dry mushrooms and enjoy their flavour and texture for an extended period.

Oven drying

Oven-drying is a great way to preserve mushrooms for long-term storage. It is also a good alternative to air-drying, which may not be practical if you live in a humid place.

To dry mushrooms in the oven, start by cleaning fresh mushrooms with a lightly dampened towel. Do not wash them under running water. Slice the mushrooms into 1/8- to 1/2-inch pieces, or cut them in half, depending on their shape. The key is to have similarly sized pieces to ensure even drying.

Arrange the mushroom slices on a clean dishtowel and gently roll it up to remove any surface moisture. Then, place the mushrooms on a baking sheet, ensuring that none of the pieces overlap or touch. You can also use a baking rack placed over a baking sheet to allow for better air circulation.

Preheat your oven to a low temperature, ideally between 150°F and 175°F (80°C). If your oven has a dehydrator setting, use that. Place the baking sheet with the mushrooms inside and leave the oven door slightly ajar to allow moisture to escape. Check your mushrooms after an hour, flip them over, and return them to the oven for another hour. Continue this process until they are dry. Thicker slices may take longer to dry, so adjust the timing accordingly.

Once the mushrooms are out of the oven, let them cool before checking if they are completely dry. Mushrooms will crisp up as they cool, similar to cookies. If they are not fully dry, return them to the oven for 30-minute intervals, flipping them over each time, until they are ready.

Properly dried mushrooms will be crispy and fragrant. They should snap when bent and feel like little rocks. Store them in airtight glass jars in a cool, dry place. Properly dried and stored mushrooms can last up to a year or even longer.

Sun drying

Sun-drying is a great way to dry mushrooms without the need for an oven or dehydrator. It is also the best method for preserving flavour and potency. The process is simple and requires no electricity, making it an easy and cost-effective method for drying mushrooms.

To begin, choose a good spot for drying your mushrooms. This could be a room that gets a lot of sun, a flat roof, or a windowsill. Ensure that the area is protected from moisture, insects, and animals. It is also important to have some airflow, so a stagnant, closed-off room is not ideal.

Next, prepare your mushrooms. Start with fresh mushrooms, and wipe them clean with a lightly dampened towel. Do not wash them under running water. You can then choose to slice the mushrooms into 1/2-inch pieces or, depending on their shape, cut them down the middle. It is important not to stack the mushrooms on top of each other, as this can trap moisture.

Now, you are ready to sun-dry your mushrooms. Place the mushrooms in direct sun for 8-10 hours with the gills facing upwards. The drying time will vary based on humidity levels and the size of your mushrooms, so be sure to check on them throughout the day. If, after a couple of days, your mushrooms are mostly dry but still flexible or have a "rubbery" feel, finish them off in an oven or dehydrator.

Once fully dried, your mushrooms should snap when bent and will be very fragrant. They can then be stored in an airtight container in a cool, dry place for up to a year.

It is worth noting that sun-drying has the disadvantage of slowly drying mushrooms at a low temperature. If dried slowly, forest-grown shiitake mushrooms, for example, can quickly decompose after picking, leading to a rapid deterioration in quality and taste. Additionally, the amount of ultraviolet rays varies depending on the season, so you may need to adjust your drying time accordingly. However, sun-drying has the added benefit of increasing the vitamin D content in mushrooms.

Freezing

• Start with fresh, high-quality mushrooms.
• Wash the mushrooms thoroughly to remove any dirt and debris.
• Trim any woody parts and stems that you don't want to consume.
• Cut the mushrooms into uniform pieces, such as quarters or slices. Small mushrooms can be left whole if they are less than one inch in diameter.
• Steam the mushrooms for the appropriate time: 5 minutes for whole mushrooms, 3.5 minutes for buttons or quarters, and 3 minutes for slices.
• Cool the mushrooms promptly after steaming.
• Place the cooled mushrooms on a parchment-lined baking sheet, ensuring they are in a single layer and not overcrowded.
• Put the baking sheet with the mushrooms in the freezer until they are frozen solid.
• Transfer the frozen mushrooms to a freezer-safe container or bag, removing as much air as possible. Seal and label the container.
• To thaw the mushrooms, you can leave them overnight in the fridge or add them directly to a pan during cooking.

It is recommended to cook mushrooms before freezing, as raw mushrooms tend to become slimy when thawed due to their high water content. Cooking or steaming the mushrooms first helps draw out internal moisture, resulting in a nicer texture and more intact mushrooms after freezing. Additionally, cooking concentrates their earthy flavor.

Some people have had success freezing sliced raw mushrooms for pizza toppings or sauces, but they recommend not thawing them before cooking. Freezing cooked mushrooms, such as roasted or sautéed mushrooms, is generally more successful and reduces the mess associated with freezing raw mushrooms.

Dehydrator

Drying mushrooms is a great way to preserve them for long-term storage. It is possible to dry mushrooms without a dehydrator, but using a dehydrator is an optimal way to dry mushrooms.

Using a dehydrator is the most expensive way to dry mushrooms, but it is a worthy investment, especially if you plan on cultivating mushrooms regularly. Dehydrators remove the water content of mushrooms using a heat source and constant airflow, which minimises the risk of contamination.

When using a dehydrator, it is important to first clean the mushrooms with a lightly dampened towel. Do not wash them under running water. Then, slice the mushrooms into pieces that are between 1/4 to 1/2 inch thick. The thicker the slices, the longer it will take to dry. Arrange the cleaned, sliced mushrooms on the dehydrator trays, ensuring that none of the pieces touch or overlap. This allows for the best airflow, and they will dry faster and more evenly. Slide the loaded trays into the dehydrator and set the device to a low-temperature setting of around 40°C. The drying process will take between 4 to 8 hours, depending on the thickness of the slices. Check on your mushrooms every hour or so to see how they are doing. Once they snap under pressure, they are ready for storage.

Other Methods

If you do not have a dehydrator, there are other methods to dry mushrooms. One way is to air dry them. Place the mushrooms in a well-ventilated area, preferably in the sun, and allow them to air-dry for 7-10 days, until they do not give when squeezed. To expedite the process, you can partially dehydrate them in the oven before air-drying. Place them in an oven heated to 175°F/80°C for 2 hours, flipping them halfway through. After this, transfer them to a colander to continue to air-dry for another 3-5 days. Once fully dried, store them in a sealed container for up to a year.

Another method is to use a desiccant, such as Epsom salt, to pull moisture out of the mushrooms. First, pre-dry your mushrooms by placing them on a piece of cardboard or a dry towel in a well-ventilated area out of direct sunlight. Alternatively, place the cardboard in front of a fan to air them out. This will pre-dry your mushrooms within a matter of hours. Then, thoroughly dry your mushrooms using a desiccant.

Frequently asked questions