Basically when the cones are sort of dry and papery to the touch. Also split one open and look for the yellow (lupiun) and if it is almost a florescent green they are good to go make sure he dries them right away at no more than 120f heat until they are dry. I get mine to 10% humidity but it is impossible without a dehydrator so around 40 is good for him then freeze them right away to keep mold from growing and ruing them.