And though it's sturdy enough to hold a cadaver, the living cocoon isn't designed with longevity in mind. It starts to decompose once it enters the ground, and in just six weeks, the coffin and its contents are reduced to compost for comparison. Conventional wooden caskets can take decades to fully biodegrade. Now, a mushroom coffin from Loop Biotech costs €995, which works out to about $1,067 in US