Plastic-Free Mushroom Leather Reaches Production-Scale Breakthrough

Researchers at Finland's VTT Technical Research Centre have developed a process that produces continuous sheets of mushroom-based leather with durability and strength comparable to traditional leather, addressing a long-standing barrier to scaling up fungal leather production.

Earlier attempts to make leather-like material from fungi grew mycelium, the thread-like root structure of fungi, in trays to form leather-like sheets. A few years ago, VTT researchers developed a process that produced continuous sheets of mycelium leather at about 1 meter (3.3 feet) per minute, a method that could be adapted for industrial manufacturing but still faced limits on the material's quality and durability.

In the new work, instead of turning fungal biomass directly into a leather-like sheet, the researchers first processed it into a thick, wet, pulpy mass and grew it in a nutrient-rich liquid. The pulp was then harvested, washed and mixed with sorbitol, which makes the material softer and less brittle, and cellulose, which adds strength, before being spread into a thin layer and dried.

The researchers used a roller system similar to those used in paper manufacturing to produce mycelium sheets about 20 centimeters (8 inches) wide and 8 meters (26 feet) long, relying on equipment already common in the biotechnology and printing industries. In laboratory testing, the material showed durability and strength comparable to traditional leather and was used to create a prototype handbag; the researchers could also add color to the pulp and adjust its texture.

The material was easy to recycle, breaking down after 28 days when submerged in water and disintegrating completely under industrial composting conditions within six weeks, though the researchers say it still needs to be more tear-resistant before moving toward mass production. The study was published in the journal ACS Applied Bio Materials.