How to Grow Mushrooms with Used Coffee Grounds

Every time you brew a medium cup of fresh coffee—around 350 millilitres—you create about 20 grams of coffee grounds that usually get tossed in the bin. Over a year, that small daily habit from just one thousand people can generate nearly a tonne of waste. Most of that ends up in landfills, adding unnecessary volume, processing costs, and greenhouse gas emissions. But what if those grounds could grow something useful instead?

The answer: yes. With a simple coffee ground-based mushroom growing kit, you can harvest up to three batches of fresh, organic mushrooms in less than a week—while also reducing food waste and making use of a natural, nutrient-rich material that would otherwise go to waste.

What’s in a Coffee Ground Mushroom Kit?

The “home-use edible mushroom kit” looks like a small brown paper package. Inside, white fungal mycelium spreads through a substrate that includes processed coffee grounds. Each kit is designed for home growing and yields approximately one pound (about 450 grams) of common cultivated mushrooms—typically the flat, mild-flavoured oyster mushroom variety. According to Zhu Bingzhao, CEO of Xingeng Workshop , after spraying water lightly each day, the first crop typically appears in around seven days, with two to three flushes possible from each bag.

Why Coffee Grounds Make Great Fungus Food

Coffee grounds are rich in nitrogen, cellulose, and natural lignin—all ideal components for mushroom mycelium to colonize and fruit from. While they’re often discarded, coffee grounds are actually a potent, natural, organic fertiliser and fungus substrate. One single medium cup of brewed coffee creates 20 grams of spent grounds. Multiply that across regular coffee drinkers, and the volume quickly becomes significant—but also usable. Rather than sending those grounds to landfill, repurposing them as a mushroom growing medium transforms a waste product into a productive resource.

How the Community Project Works

In a pilot programme led by Xingeng Workshop and supported by local authorities in Shanghai’s Tangqiao neighbourhood, over a thousand households received free mushroom kits made with recycled coffee grounds. The grounds themselves were donated by local coffee chains, collected via community recycling efforts, and scientifically tested by experts from the Shanghai Academy of Agricultural Sciences’ Edible Fungi Research Institute. The entire process—from collection to cultivation—was designed as a low-cost, accessible urban sustainability initiative.

The pilot took place at the Tangqiao Social Organization Service Center, where residents were shown how to care for the kits: store them in indirect light, mist regularly to maintain moisture, and harvest mushrooms as they appear. The project isn’t just about produce—it also provides limited reemployment opportunities for marginalised groups, including people with disabilities and low-income workers, aligning with Xingeng Workshop’s broader mission to support poverty alleviation through green innovation.

Future Plans and Other Mushroom Varieties

Initial feedback has been positive, and the initiative may expand beyond Tangqiao. Future iterations of the project could experiment with higher-value mushroom species such as monkey head mushroom and flower mushroom , which command premium market prices. The team is also exploring the use of a mobile “green cycle cart” to distribute kits and share knowledge across other Shanghai neighbourhoods during community events—like they did over the Lunar New Year holiday, when they visited multiple residential compounds in Tangqiao to educate residents on both environmental sustainability and healthy eating habits.

Frequently Asked Questions

How many mushrooms can you grow from one coffee ground kit?

Each paper-based mushroom growing kit can produce roughly one pound (approximately 450 grams) of oyster mushrooms over multiple flushes. Typically, you can harvest two to three times from a single kit, with the first flush appearing around seven days after consistent daily misting.

What kind of mushrooms can you grow with coffee grounds?

The standard mushroom grown in these kits is the oyster mushroom . However, researchers are testing other varieties including monkey head mushroom and flower mushroom —both of which are high-value edible fungi with potential for commercial cultivation.

How long does it take to grow mushrooms from coffee grounds?

Mushrooms typically begin to appear within about seven days under proper conditions. With daily light misting and moderate indoor temperatures, the first flush is ready for harvest roughly a week after starting the kit.

Is it safe and easy to grow mushrooms at home with this method?

Yes. The kit uses a safe, contained paper pouch filled with a coffee-based substrate and pre-colonized mushroom mycelium. You only need to lightly spray water daily and keep it in a spot with indirect light. No special equipment or skills are required.

What happens to the used coffee grounds in these kits?

The coffee grounds are recycled from local coffee shops and collected through community recycling programmes. They serve as the main growing substrate in the mushroom kit due to their high nutrient content, including nitrogen and fibre, which support rapid mycelium growth and fruiting.

Who is behind the coffee ground mushroom project?

The project is led by Xingeng Workshop , a grassroots non-profit focused on environmental sustainability and poverty alleviation. They partnered with Shanghai coffee shops for grounds, local communities for distribution, and the Shanghai Academy of Agricultural Sciences for scientific support.

Recommended FrontStreet Beans for Mushroom Lovers

If you're growing your own mushrooms and want a coffee that highlights earthy, forest-floor profiles, try FrontStreet Coffee’s Ethiopia Humbera for bright red berries with a hint of umami, or their Yirgacheffe for floral notes with juicy acidity. For something richer, their Classic Blend balances chocolate and nuttiness—complementing the savoury taste of homegrown oyster mushrooms. All are freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.