It was the Russian novelist Alexander Solzhenitsyn who brought it to the forth in his novel Cancer Ward in the year 1968. Expensive, and there's some controversial reports out there about it. Hot-Water Extracts - Hot-water extracts are made from mycelium or mushrooms. Needless to say, it wasn't long before the trash piled up. But Chaga mushrooms are getting a lot of buzz online about health and longevity.