Frequently asked
Twelve questions, answered honestly.
If you have a question here that we missed, email us at hello@supercool.com.
How long until my first harvest?
Seven days from the moment you press start. Most varieties produce a second flush 7–10 days after the first, and a third a week after that. From one log, you can expect up to 800 grams across three flushes.
What if my log doesn't fruit?
We replace it. Our logs have a 95%+ first-flush success rate. If yours doesn't produce within 14 days, email us a photo and we'll send a fresh log on us.
Do I need to use the SUPERCOOL brand of logs?
The Box is calibrated for our logs because we control the substrate composition, water content, and mycelium density. Third-party logs will work but we can't guarantee the same yield or flavor profile.
How much does it cost to run?
About $0.50 a month. The Box pulls 13 watts continuously — less than a reading lamp. Running it 24/7 for a year adds about $6 to your electricity bill.
Is it safe to have in a living space?
Yes. The chamber uses a negative-pressure airflow cycle that keeps spores inside the box. It's safe around kids, pets, and people with asthma or mushroom allergies. The ABS housing is FDA-grade food-safe plastic.
Does it work in any climate?
The Box is calibrated for ambient indoor temperatures of 18–28°C. It works in most homes year-round. If your kitchen is below 16°C or above 32°C, the harvest may slow.
Can I grow other mushrooms too?
We support six culinary varieties: Shiitake, Lion's Mane, Golden Oyster, Oyster, King Oyster, and Maitake. We're working on more — there's only so much climate research we can do in a year.
Is there an app?
No. The Box has a touch interface on the front panel. You can see the temperature, humidity, CO₂, and grow timer in real time. You'll never need a phone to use it.
How loud is it?
About 35 dB — quieter than a library. The fan cycles on and off automatically. You can sleep next to it.
What happens if I forget to refill the water?
The Box will alert you on the touchscreen and pause the climate cycle. Mushrooms won't die — they'll just stop growing. Add water and the cycle resumes.
Where do you ship?
Currently the contiguous US. International shipping is on the roadmap. Each Box is hand-assembled in Hefei and ships from California — typically within 2 weeks of order.
What's your return policy?
30 days, no questions asked. If the Box doesn't grow mushrooms for you, send it back for a full refund. We also have a harvest guarantee on every log — if it doesn't fruit, we replace it.