The Surprising Benefits of Growing Mushrooms in Coffee Grounds

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If you’re looking for an eco-friendly way to grow mushrooms, using coffee grounds is an excellent option. Not only does it divert waste from landfills, but it also creates a nutrient-rich substrate that mushrooms love. Plus, the process of growing mushrooms in coffee grounds is straightforward and rewarding.

In this article, we’ll look at the details of growing mushrooms in coffee grounds, from the materials you need to the steps to follow. We’ll also cover common questions about this technique and its benefits.

The Basics of Growing Mushrooms in Coffee Grounds

Before we dive into the specifics of this technique, let’s first understand why coffee grounds are an excellent substrate for mushroom growth. Mushrooms thrive in environments that are rich in nutrients and moisture. Coffee grounds are both of these things, thanks to their high nitrogen content and ability to hold moisture. By using coffee grounds as a substrate for growing mushrooms, you’re creating an ideal environment for their growth.

Here are the basic steps to growing mushrooms in coffee grounds:

Materials You’ll Need

  • Coffee grounds
  • Mushroom spores or spawn
  • Container or grow bag
  • A misting bottle or spray bottle
  • A sterile environment to work in

Step by Step Instructions

  1. Collect coffee grounds from a local cafe or make your own at home (one pound of coffee grounds is enough for one grow bag).
  2. Mix the coffee grounds with mushroom spawn or spores.
  3. Fill a container or plastic bag with the mixture, leaving enough room for the mushrooms to grow.
  4. Poke holes in the container or bag for air circulation.
  5. Mist the substrate with water daily to keep it moist.
  6. Place the container or bag in a warm, dark place with good airflow (around 70-75°F).
  7. Watch the mushrooms grow! Depending on the type of mushroom, it may take anywhere from a few weeks to a few months for them to mature.

Benefits of Growing Mushrooms in Coffee Grounds

Growing mushrooms in coffee grounds has numerous benefits, both for the environment and for the mushroom growers:


By using coffee grounds as a substrate, you’re diverting waste from landfills. In the US alone, it’s estimated that 25 billion pounds of coffee waste go to landfills each year. Instead of contributing to this waste, you can use it for mushroom growth.

Rich in Nutrients

Coffee grounds are a rich source of nitrogen, making them an ideal substrate for mushroom growth. Mushrooms also require other nutrients, such as potassium, phosphorus, and calcium, which may need to be added to the substrate.

Easy to Source

Coffee grounds are readily available, especially if you live near a coffee shop. You can often pick them up for free or at a very low cost.

Delicious and Versatile

Mushrooms grown in coffee grounds are just as tasty and nutritious as those grown in other substrates. Plus, you can grow a variety of mushroom types using this technique, from oyster to shiitake to lion’s mane.

FAQs About Growing Mushrooms in Coffee Grounds

Q: Can I use any type of coffee grounds?
A: Ideally, you want to use coffee grounds that are freshly used (within a day or two). Avoid using grounds that have been sitting for too long, as they may have started to break down and lose their nutrients.

Q: Do I need to sterilize the coffee grounds?
A: No, coffee grounds are already a sterile environment. However, you do need to be careful about introducing contaminants when mixing the mushroom spawn or spores into the substrate.

Q: How do I know when the mushrooms are ready to harvest?
A: The mushrooms will mature at different rates, but you’ll typically see small pinheads forming on the surface of the substrate. These will grow into mushrooms over time.

Q: Can I reuse the substrate?
A: Yes, you can typically get two or three flushes of mushrooms from one batch of substrate. After the first flush, give the substrate a break for a few weeks before using it again.

In Conclusion

Growing mushrooms in coffee grounds is an excellent way to create a nutrient-rich substrate for mushroom growth while diverting waste from landfills. It’s a simple and rewarding process that yields delicious and versatile mushrooms. By following the steps outlined in this article, you’ll be well on your way to cultivating your own crop of mushrooms in no time.


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