- Mushrooms can be grown in reusable plastic bottles. Enoki is already grown in them but they are gaining in popularity for oysters. - Yes, no way around spawn

- Mushrooms can be grown in reusable plastic bottles. Enoki is already grown in them but they are gaining in popularity for oysters. - Yes, no way around spawn or lab equipment. - Humidification is relatively low energy. Even a regular consumer-grade humidifier will be enough for an amateur grow operation. And even for larger humidifiers, the water and energy requirement is minimal. - You can pasteurize substrate with zero-energy methods like cold pasteurization (via calcium hydroxide) or composting (industry standard right now, basically what all commercial button mushroom farms do). - Sterilization of spawn is indeed high energy, but using electric desktop autoclaves (AA has a few models) significantly reduces energy use. They are used quite rarely commercially, though.