Growing Mushrooms in Coffee Grounds at Home

Last Updated on April 4, 2024 by Real Men Sow

Mushrooms are notorious for being hard to grow due to the mass-produced kits that were low-quality. If you want to know how to grow mushrooms easily, follow this guide. Let’s find out the best ways for growing mushrooms in coffee grounds right at your home without any equipment. 

How to Grow Mushrooms in Coffee Grounds

Mushroom Life Cycle

The life cycle of a fungus exists because of mycelium, the dense and root-like network of cells. The network grows out in all directions in the wild. It breaks down food to fuel its growth and when it runs out, it produces mushrooms to release its spores and find a new place to live. Therefore, it’s difficult to reproduce this system at home. Oyster Mushroom

What kind of  Mushrooms Grows in Coffee Grounds?

The Oyster Mushrooms are the best variety to start with when you are planting in used coffee grounds. People grow these mushrooms on hardwood logs or shredded straws, however, there’s a big catch to both of these two. Hardwood Logs are difficult and unpredictable, it might take a long time before you can harvest the mushrooms. Shredded Straws need to be pasteurized to kill off other microorganisms that may compete with your mycelium. Special mushrooms like shiitake mushrooms grow on trees so these probably won’t go well in coffee grounds.


Grown on Hardwood LogsUsed Coffee Grounds is the perfect material for growing mushrooms since it has already been pasteurized by brewing. It’s also nutritious and that’s where Oyster Mushrooms love to grow.

Inoculating Process for Growing Mushroom

You’ll need to order your spawn in, it’s recommended you use a high spawn. Use 500g of your oyster mushroom spawn to 2.5kg of coffee grounds. Purchase filter patch grows bags if available to increase your chances of success. However, if there’s no luck in finding one, you can use a 2L freezer bag, milk carton, or an empty ice-cream tub that has been cleaned out well with 4mm by 5mm holes in the sides.

Collect the Coffee Grounds for the Growing Mushrooms

You need to fill your bag or container two-thirds full of coffee grounds. So, it’s suggested that you ask a busy cafe nicely if they can give you their used coffee grounds. Make sure to use the coffee grounds you asked for that day. Weigh 2.5kg of coffee grounds and place it in a mixing bowl. 

Make sure to wash your hands before mixing your spawn into the bowl with coffee grounds. Evenly distribute the spawn throughout the coffee grounds. Put the mixture in your container and close it shut.

How Long Will It Take To Grow Mushrooms?

Your container must be in a warm, at 18°C – 25°C and dark location, (ex: cupboard, under a bed). After three weeks, the spawn should have turned white. 

How does the Fruiting Process look like?

The mixture in your container should be white. Add a little salt if there is a small patch of green in the mixture, this would kill off the competitor mold and allow the mycelium to claim the place. If the mixture in your container turns completely green, you may need to start over. Make sure you use high-quality spawn, fresh used coffee grounds, and follow proper hygiene throughout the process. 

Put the container at a spot with widely available fresh air and a little light. You should cut a 5cm by 5cm square hole in your container, this is the spot where you will spray twice a day with water. Make sure to keep it damp. One week later you’ll see that small mushrooms will start to appear. Leave it for a week again and it would be twice the size. Harvest them as soon as the edge of their caps begins to turn upwards. Just cut the base of the stems and start cooking.

Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.