How do I pasteurise straw for oyster mushrooms?

Chop the straw, then either soak it in hot water held at 65 to 80°C for one to two hours, or use cold lime pasteurisation by soaking it in water raised to a high pH with hydrated lime for 12 to 18 hours. Drain until it holds moisture but does not drip, which is around 65 to 70% moisture. Cool it, then mix in grain spawn.