A prehistoric multitool
In the forests of Uusimaa, attached to birch trees, grows a woody, hoof-shaped mushroom with a long history of human use. Fomes fomentarius, commonly known as the tinder fungus or hoof fungus, is a parasitic mushroom that causes white rot in trees. Its connection to humanity is most famously demonstrated by Ötzi the Iceman, the 5,300-year-old mummy discovered in the Alps in 1991. Among his meticulously curated equipment was a pouch containing pieces of this fungus, part of a sophisticated fire-starting kit. This find shows that as early as 3,300 BCE, humans were making fire, but mastering its transport, carrying embers within the fungus to reliably start a new fire regardless of weather conditions.
The fungus's utility comes from a soft, fibrous layer inside its hard exterior called the trama. This material is processed into a substance known as amadou. The creation of amadou is a labor-intensive process that involves separating the trama layer from the hard outer crust and the pore-filled underside. The trama is then often boiled, sometimes in an alkaline solution like water with wood ash, and pounded with a mallet. This breaks down the fibers, resulting in a soft, absorbent, felt-like material that is exceptionally good at catching a spark from flint and pyrite. It does not flame, but smolders with a hot, long-lasting ember that can be used to ignite other tinder.