Use of coffee grounds as a substrate for home mushroom cultivation eliminates the need to sterilize straw or sawdust typically used by commercial farms with boiling water. Sterilizing straw at home is both messy and inconvenient; additionally, its reduced nutrient content delays fruiting or prevents it altogether. By mixing spent coffee grounds with straw and organic materials like composted manures, the substrate becomes better balanced for mycelial growth, while supplements like gypsum enhance soil structure and aeration for vigorous mycelial growth with high yields.

To prepare the substrate, place straw in a bucket or other container and mix with about 70 percent coffee grounds and 20 percent straw; this should fill the container. Mix mushroom spawn evenly through this mix before adding enough warm water to dampen but not completely wet it; this will allow the spawn to settle more effectively while helping prevent mold growth.

Once your spawn has been colonized by mycelium, place the entire mixture into the refrigerator for 12-24 hours to undergo what’s known as cold shock treatment and promote fruiting of certain mushroom species such as blue and yellow oyster mushrooms and others. Although not necessary in all cases, cold shock treatment will usually improve fruiting of such mushrooms as well as others that produce them.

Once mycelium has completely colonized your mixture, place it in a dark area and periodically mist with water – this should help maintain humidity between 85-95%; using a hygrometer is a useful tool to monitor and adjust this level while also helping identify issues like lack of light or poor air exchange.

Grow bags can be ideal for this process; however, other suitable options include large freezer or ice-cream bags which have been thoroughly cleaned out and with holes drilled for ventilation purposes. A large bucket with lid, empty milk carton or clean ice cream tub may also work.

Once pinhead mushrooms begin forming after about two to three weeks, move your bag to an area with indirect sunlight and continue spraying daily with water until their tops start flattening out; that is when harvest time arrives!

Many people enjoy mushrooms as a tasty and nutritious snack or way to add depth and dimension to meals. Cooked and eaten alone as an entree or added into soups and stews for their earthy flavors, they can even be dried for future consumption. If you want to try growing mushrooms at home, follow all directions carefully so they come out right – then sit back and relish their delectable flavors alongside friends and family members alike!