A coffee degassing method is disclosed. A diffusion gas is supplied into a degassing tree in an bin containing roasted coffee. The degassing tree is in the roasted coffee. Carbon dioxide is diffused from the coffee with the diffusion gas. Carbon dioxide and the diffusion gas are exhausted from the bin. Another method of coffee degassing is disclosed. A diffusion gas is supplied into a degassing chamber in a bin containing roasted coffee. The degassing chamber is in the roasted coffee. Carbon dioxide is diffused from the coffee with the diffusion gas. Carbon dioxide and the nitrogen are exhausted from the bin.