Preserving Your Wild Mushroom Harvests through Freezing, Canning, and Salt-Brining

Lots of hens to preserve

When the wild mushrooms fruit in abundance, the picking can be pretty intense in southern New England. Some years the weather conditions cooperate and we get warm temperatures and abundant rain which translates into flushes of black trumpets and enough Boletes to fill shopping bags and car trunks with mounds of fungi (2014, 2018); other years we have heat waves, drought, and gypsy moth caterpillar attacks that leave us crying through the summer (2016, 2017). To keep our tummies full and taste buds satisfied in lean years, we collect what we can in the good years and preserve it in several ways to tide us over in the leaner years, and often share our excesses through potlucks and holiday dinners with friends using out-of-season foraged foods that have been stored safely. We don't have a massive home or pantry, but make due with some shelves and small chest freezers for our wild edibles. We also have made some purchases of a few specialized pieces of equipment to make preservation easier, and can heartily recommend the Excalibur dehydrator, and a Foodsaver vacuum sealer with plastic bags and optional jar sealing attachment.

Cooking and Freezing

When it comes to freezing mushrooms, we feel it is best to cook them first for a couple of reasons. First, it greatly reduces the volume of the mushrooms when you cook them, taking up much less freezer space. We try to cook them in the least amount of neutral oil needed, just until they have given up their juices and have become dry in the pan. That way, they can portioned into plastic bags, vacuum packed in plastic bags, or placed in hard containers with the least amount of liquid. If you want smaller portions for smaller recipes, portion the mushrooms out into smaller containers or into an ice cube trays, then pop out the mushroom "cubes" and then bag those up in plastic with most of the air removed. The second reason for cooking the mushrooms before freezing is that it prevents the formation of ice crystals in the raw mushrooms. The ice crystals will burst open the cell walls of the mushrooms, resulting in mushy, wet, flabby mushrooms once thawed out for use in recipes, a rather unappetizing texture.

Meadow mushrooms, good to cook and freeze for recipes

Many of the gilled wild mushrooms we collect are very good candidates for the cooking and freezing method of preservation. We keep winecaps, meadow mushrooms and other edible Agaricus, oysters, and honey mushrooms in the freezer, ready to thaw and add to dishes. Chanterelles are another wild mushroom that fare better with the cook and freeze method since they don't re-hydrate well from dried. Some of the tougher polypores like the chicken mushroom or Berkley's polypore should never be dehydrated, but cooked and frozen for later use. Even a tender polypore that we can dehydrate successfully, the hen, works well cooked and frozen as whole fronds, shredded into strips, or finely chopped in the food processor like ground meat. 

Wild Rice and Hen soup, keeps well in the freezer in large plastic containers

Other wild mushroom items we keep in the freezer are already prepped dishes. These include things like Thai curries made with coconut milk and curry paste that include cooked wild mushrooms. When we want to eat this dish, we just need to that out the curry sauce, heat it up, add some fresh vegetables, and serve over cooked jasmine rice. Pot pie bases with wild mushrooms keep well in the freezer, with the cooked wild mushrooms--usually hens--carrots, celery, peas, herbs, and the thick gravy. When we need it for dinner, I remove it from the freezer, thaw it, add a fresh top crust, and bake it all together. Mushrooms soups can be frozen in single or larger family sized portions. Patties or "burgers" made with ground mushrooms with egg or breadcrumbs as binders can be par-baked and frozen; I find it is best if they are frozen individually on a sheet pan first, then stacked with a small piece of parchment between each patty inside of a bag to prevent sticking. To reheat, just thaw and microwave, or heat in the oven or in a skillet.

Pickling, Canning, Marinating, and Salt-Brining

Two long term methods of keeping your mushrooms preserved would be pickling or canning. We personally haven't done very much of either of these. To stay safe and avoid botulism, it is strongly

recommended to not can wild mushrooms at all and the method suggested for button mushrooms is actually pressure canning. It is important to add enough acid to bring the brine to a pH level of 4.6 or lower to stay safe. Use paper pH test strips or a digital pH tester to check the acidity levels. Marinating mushrooms in a flavorful dressing for short term storage in your refrigerator can produce a great snack for a pickle tray or garnish a mixed drink. We like to use small button honeys or Agaricus for something like this, and make a sweet and sour marinade that tastes similar to a cocktail onion, and soak the mushrooms for 3 days to a week or so. Using a good Italian dressing is another option for marinated mushrooms as well.

Salt Brined Lactifluus mushrooms

Salt brining mushrooms for long term preservation is a technique that Robert was familiar with from Hungary, one that his family used. We use it for a few edible Lactifluus species we like to collect, L. volemus, L. hygrophooides, and L. corrugis. This method would also work with Russulas, honeys, Agaricus, Leccinum, hens, or any other firm-fleshed mushroom that can withstand an initial boil. First, the mushrooms are cleaned of debris, then cut into manageable pieces. They are then boiled for about 10-15 minutes then cooled. We then place them in a single layer in a jar and sprinkle with a heavy layer of sea salt. Another layer of mushrooms is added and another layer of salt, until the jar is filled or you run our mushrooms. After a day or so, the mushrooms will let out some liquid, but you will have to add some fresh water, enough to cover the mushrooms so that none are exposed to the air. The mushrooms can then be kept in a covered jar or crock in a cool place for a year or two, if you don't eat them first! They will be incredibly salty, so to use them in a dish, you need to de-salt them first. We do this by taking out what we need for a recipe and soaking it in a few changes of fresh water for 2 days in the refrigerator. The mushrooms will be quite good and have excellent texture, which is why it is important to start with firmer mushrooms to begin with.

Chowder made with Salt-Brined Lactifluus mushrooms, after soaking to remove the salt

Preserving your wild mushrooms can provide you with tastes of your harvests for many months after your foraging, and the more ways you know to keep your bounty fresh and safe, the more options you have for the best tasting food.