Danish Biologists Cultivate Morel Mushrooms Year-Round With New Indoor Technique

In the world of edible mushrooms, the morel mushroom is one of the most coveted and tasty species. In spring, the highly seasonal mushrooms are found in forests all over the Northern Hemisphere among leaf litter around dead elm, Sycamore, apple, and Ash trees. Despite their popularity, the mushrooms are difficult to cultivate indoors. While some attempts have been made, the yield and quality of the product varies. 

Now, two Danish biologists Jacob and Karsten Kirk, who are also twins, have found a reliable method to cultivate hefty amounts of morels indoors in a climate-controlled environment year-round, reports Alla Katsnelson for the New York Times. The technique is the culmination of four decades of research conducted in collaboration with the Royal Veterinary and Agricultural University and the University of Copenhagen, per a statement. The growing method produces 4.2 kilograms of mushrooms over a 22-week growing cycle, which is equivalent to about 10 kilograms per square meter, or 20 pounds of mushrooms per square yard, per year.

Morels are wild fungi that stand three-to-six inches tall. They sport a cone-shaped, wrinkly, lattice cap that ranges in color from cream to chocolate brown. They are treasured in the culinary world for their earthy and nutty taste, reports Lauren Rothman for Tasting Table. (Rothman recommends enjoying them in a springtime pasta dish or sliced atop toasted bread with a good quality butter.) Fresh morels sell for $50 per pound or $200 per pound if dried, per the New York Times.

“The cost per square meter for producing a morel will be roughly the same as producing a white button mushroom,” Karsten Kirk tells the New York Times. Cultivating the mushrooms indoors could bring the cost of the fungi down.

Cultivated morels have some benefits and advantages that foraged morels lack. Chefs note morels grown in nature carry dirt, slugs, and bugs, and while the grime and pests can be washed off, wetting the cap degrades its texture. Too much sun or rain can also ravage the cap’s signature wrinkles, per the New York Times. 

Unlike other wild mushrooms, the sought-after fungi are difficult to cultivate due to an extra step in their life cycle called the sclerotium. To germinate in spring, the sclerotium can either form new mycelium, the root-like network of underground filaments, or they can form a fruiting body, which is the above-ground mushroom.

Growers can quickly get the sclerotium to form new mycelium, but it is difficult to force it to create the fruiting body. To produce the mushroom, specific nutritional conditions, humidity, carbon dioxide levels, and temperatures need to be met.

The Kirk brothers detail their story—from the first experiment to the final product—on their webpage The Danish Morel Project. The duo studied optimal growth conditions, created nursery pallets and climate chambers, and mixed a special blend of morel soil. Based on observations in nature, the Kirk brothers found including grass in the soil stimulates the morel’s mycelium, the New York Times reports.

They also identified ideal genetic variants for mass production. Their best strain is Variant 195, a type of black morel that develops fast and can be harvested early.

Their direct methods of cultivating the morels indoors are not detailed fully because they are protected under patent law, according to the Danish Morel Project website. The pair says commercial production can begin after appropriate automation of the cultivation process.

Elizabeth Gamillo | | READ MORE

Elizabeth Gamillo is a correspondent for Smithsonian and a science journalist based in Milwaukee, Wisconsin. She has written for Science magazine as their 2018 AAAS Diverse Voices in Science Journalism Intern.