EastScape Wikibuilt from the game itself
Black truffle spawn
“Plant it in a fungus bed in your cellar (Fungiculture 65) with 2 compost. It grows black truffle, and gives spawn back.”
How to get it
- Scraped up with the shroom 35% of the times you pick wild Black truffle (Fungiculture 65), and given back by every bed you harvest.
Grows
Plant it in a fungus bed in your cellar (Fungiculture 65, 2 compost): grows 
Black truffle in about 180 minutes, and gives spawn back.