Coffee grounds trial

First Observations

We’ve been experimenting with spent coffee grounds as a substrate for oyster mushrooms - our goal: turn urban waste into fertility right in our home spaces.

Here’s how we played:

• We collected coffee grounds from our kitchen and a local café.

• Mixed them with small amounts of cardboard and straw to balance texture.

• Inoculated them with oyster mushroom spawn in jars and small trays.

• Observed the mycelium weaving through the substrate over the course of two weeks.

Early observations: the mycelium colonized quickly, forming thick white networks and producing a sweet earthy aroma. By the end of the cycle, what was once waste became rich, dark compost, ready to feed our soil. It’s amazing to see urban scraps completing their journey back to fertility, and it’s proof that small experiments at home can ripple into bigger cycles in soil systems.

Insight: even small variations in moisture or cardboard ratios changed colonization speed, reminding us that fungi are sensitive collaborators and that observation and curiosity are as important as technique.