Spore Prints – Self-sufficiency for Mushroom Growers
If you grow edible or medicinal mushrooms, you really should be extending the lifetime of your favourite strains by making spore prints. Not only is this fun, but it’s highly economical too!
Perform these instructions in the most sterile environment available to you. If you don’t already have a still air box, search online for ‘still air box construction’ for cheap and simple plans. Every home mushroom grower will benefit from owning one of these, ensuring a reduced risk of contamination.
You will need –
70% isopropyl alcohol or alcohol wipes
Large glass jar
Extra-thick / heavy-duty foil
Lysol / Oust disinfectant spray
Mushroom caps (one per print)
Scalpel or sharp knife
Still air box
CD case (or other portable surface)
- Spray your workspace with disinfectant, put on your gloves, and wipe them down with alcohol.
- Wait a few minutes in another room while the disinfectant does its work.
- Cut two-inch square pieces of foil, two squares for each print you plan to make.
- Put the squares of foil into the glass jar.
- Cut another strip of foil, fold it in half, and use in place of a lid for the jar.
- Sterilise the jar and its contents by baking in the oven for one to two hours at 250°C.
- While the jar is baking, choose the mushroom caps which you will use to make the prints.
- Once the jar is finished baking, allow it to cool completely for several hours.
- Wrap the CD cases in squares of paper towel and place into the still air box.
- Place everything else needed inside the still air box.
- Spray inside and around the box with disinfectant, put the lid on the box, and wait a few minutes for the spray to take effect.
- Disinfectant your gloves with alcohol once more.
- Inside the still air box, carefully remove the foil lid from the jar.
- Remove the squares of foil one by one, and place shiny side up onto the CD cases, one square per case. Cover each with an upturned shot glass as you go.
- Put the lid back on the jar.
- Disinfect the scalpel with alcohol and cut the chosen mushroom caps from their stems. Ideally, the caps should sit flat on the foil, so try to cut away as much stem as possible.
- Holding each cap by its edges, place inside the still air box (use the holes so the foil does not meet ‘fresh’ air).
- Lift a shot glass, place the cap on the foil square, and re-cover. Repeat until all the caps are on their squares.
- To ensure good spore prints, leave everything to sit in the still air box undisturbed for 36 to 48 hours.
- After 36 hours, add an unfolded paper clip and some alcohol or wipes to the still air box contents.
- Again spray the room and still air box with disinfectant and wait a few minutes for it to take effect.
- Put on a fresh pair of gloves and wipe down with alcohol.
- One by one, remove the shot glasses and gently pierce the caps with the paper clip – just enough to lift them straight up and off. Don’t slide the cap around or puncture the foil.
- Re-cover each of the spore prints as soon as the cap has been removed.
- The caps can now go to dry with the rest of your harvest as normal.
- Leave the spore prints somewhere to dry for at least 24 hours, preferably with some desiccant gel nearby.
- Once the spore prints are dry, spray some more disinfectant and wait a few minutes.
- Put on some gloves and disinfect with alcohol.
- Inside the still air box, uncover the prints one by one by removing the shot glasses.
- Disinfect the ruler and scissors with alcohol.
- Trim the excess foil from each print, leaving a small square.
- Remove the foil lid from the jar and, holding it shiny side up, take out a square of foil.
- Using the ruler, make a crease along one side, roughly 5mm from the edge.
- Take a spore print and place it print-down onto the unprinted square, tucking one side in the crease.
- Fold the crease tightly over to hold the spore print in place.
- Holding by the folded side, cut the excess from the unprinted foil, leaving around 5mm on each of the three sides.
- Crease the remaining three sides up over the printed foil.
- Label the unprinted side of the foil using a marker pen. List the date, strain, and anything else relevant.
- Place the finished spore prints inside a clean Ziploc bag and store somewhere cool, dry, and dark for later use.