Mushroom production at Kuckucksmuehle
Aim
Produce enough mushrooms to meet local demand for mushrooms, eliminating the need to buy mushrooms. This should be as low-maintenance as possible and as automated as practical.
If this proves successful, supplying fresh mushrooms to nearby shops and restaurants should be considered, increasing the production accordingly.
After some consideration it was decided to try growing Oyster Mushrooms initially. This is because they are easy to grow, as they grow well in a wide range of environmental conditions. There are several varieties of various oyster mushrooms:
- Oyster mushrooms
- King oyster mushrooms
- Golden oyster mushrooms
- Blue oyster mushrooms
Projected output volume and savings estimate
The proposed setup uses 24x5l buckets, spread out in 6 batches of 4 buckets.
Each 5ltr bucket is projected to produce an average of 0.2kg of edible mushrooms every 3 weeks, which is about 1.6kg of mushrooms / week. Mushrooms cost €9/kg, so each week will save €14.40 in mushrooms. Over 1 year it is expected to save €750, producing 83kg of edible mushrooms.
| Week | Batch 1 | Batch 2 | Batch 3 | Batch 4 | Batch 5 | Batch 6 |
|---|---|---|---|---|---|---|
| 1 | Harvest 2 | Wait | Wait | Harvest 1 | Wait | Wait |
| 2 | Wait | Harvest 2 | Wait | Wait | Harvest 1 | Wait |
| 3 | Wait | Wait | Harvest 2 | Wait | Wait | Harvest 1 |
| 4 | Harvest 1 | Wait | Wait | Harvest 2 | Wait | Wait |
| 5 | Wait | Harvest 1 | Wait | Wait | Harvest 2 | Wait |
| 6 | Wait | Wait | Harvest 1 | Wait | Wait | Harvest 2 |
Projected running costs
| Item | Cost | Cost in € | Comments |
|---|---|---|---|
| Labour | 312 hours / year | 441 / year | Assumes 2 volunteers for 3 hours each per week at €1.26/hour |
| Straw | 1040kg / year | 195 / year | Assumes we need 5kg of straw/bucket, and bales are small |
| Water | ??? | 0 (local) | |
| Electricity | ??? | 0 (local) | |
| Air filters | 2 / year | 20 / year | Assumes new filters every 6 months |
| Respirator filters | 4 / year | 40 / year | Assumes new filters for both respirators every 6 months |
| Gloves | 0 (sourced) | ||
| Replacement buckets | 96 / year | 144 / year | Assumes buckets last for 6 months, cost €1.50 each |
| Total | 840 / year |
Proposed setup
Location
Mushrooms require a stable temperature. Therefore the cellar is an obvious location for the mushroom growing space.
Enclosure
Inside the cellar we want to create a stable environment where temperature, CO2, and moisture levels can be controlled. This environment should not be contaminated by the outside environment, i.e. prevent spores and microorganisms from outside from entering inside. It should also avoid contaminating the cellar itself, i.e. prevent large amounts of spores and moisture escaping from the enclosed space and degrading the structure of the house.
Physical structure for enclosure
- Hydroponic grow tent
Carbon dioxide control inside tent
- 120mm PC fan blowing air into the grow tent from the cellar
- Can be linked up to CO2 censor to only turn on when needed
Prevent contamination from the outside
- Particulate filter on the fan vent
Prevent contamination from the tent to the cellar
- Output fan ducted to the outside through the window
- Metal grill to prevent rodent ingress from the outside
Moisture control inside the tent
- Mister linked to a humidity sensor
Temperature control inside the tent
- Heater linked to a temperature sensor
Light
- Mushrooms do not need much light, but some should be there.
Cleaning / maintenance
- Cloths and steriliser to wipe down the inside of the tent and shelving unit
- Brush to clean out the air supply vents
Problems
- Rodent ingress through the tent structure
- Maintaining positive internal pressure in a system with an outlet fan
- No response to overheating
- Not currently any system for alerting to abnormal conditions
Inside the enclosure
- Shelving system to accommodate the growing mushrooms. It should be spore and corrosion resistant, and should be easy to clean.
On the shelves
- Buckets with holes drilled into them containing the growth medium
Growth medium
- Straw - it is suitable for the mushrooms we want to grow (oyster mushrooms), and we have an ample supply. Wood chips would also be suitable.
Sterilising the growth medium and buckets
- A large pressure boiler or pot with a heater to heat up the straw in buckets to above 80 degrees. Needs to be large enough to contain a full bucket.
Harvesting
- A table
- A knife
- Container for freshly harvested mushrooms
Personnel Protection Equipment
Spore exposure can initially lead to flu-like symptoms, and then develop into a permanent mushroom allergy. To avoid that, spore contamination of people should be avoided as much as possible. At the same time, when working with mushrooms, the intended growth sites should not be contaminated by things that we do not want to grow. Hence, what is needed is:
- Particle filter masks to avoid breathing spores
- Gloves to avoid contaminating the growth sites
- Clean clothing / coats to avoid contaminating inside
- Hair netting / shower cap to avoid cross contamination
- Keep the growth area shoe free
Procedure
Initial setup
Purchase parts
TODO: BOM
Assemble the setup
Erect growing tent
TODO: Instructions
Add lights
TODO: Instructions
Add shelving system
TODO: Instructions
Add air intake
TODO: Instructions
Add air outtake
TODO: Instructions
Add mister
TODO: Instructions
Add heater
TODO: Instructions
Add shelving unit
TODO: Instructions
Add workbench
TODO: Instructions
Add steriliser
TODO: Instructions
Add location to store PPE
TODO: Instructions
Prepare buckets
TODO: Instructions
Continuous running
Once the above is set up, the procedure for growing the mushrooms is:
| Task | Time estimate in minutes per week |
|---|---|
| Clean the buckets | 20 |
| Place straw into buckets | 20 |
| Sterilise the buckets | 120 |
| Introduce mushroom culture into the buckets | 30 |
| Place buckets onto the shelf in the enclosure | 5 |
| Wait for mushrooms to grow (about 3 weeks) | 0 |
| Harvest mushrooms | 60 |
| Wait for mushrooms to grow again (about 3 weeks) | 0 |
| Harvest mushrooms again | 60 |
| Place straw into compost | 10 |
| Perform maintenance tasks | 30 |
| Go back to the beginning | 0 |
| Total time | 5h55m |
Cleaning the bucket
TODO: Instructions
Placing straw into bucket
TODO: Instructions
Sterilising the bucket with straw inside
TODO: Instructions
Introducing mushroom culture to the straw
TODO: Instructions
Waiting for the mushrooms to grow
TODO: Instructions
Harvesting
TODO: Instructions
Maintenance
TODO: Instructions
Composting
The straw leftover form the mushroom production can be added to the garden compost when in large quantities or the vegetable compost in smaller quantities eg. 1 bucket a week is ok for the vegetable compost but anything over this would have to go in the garden waste compost as it would need to be mixed with additional organic matter to compost effectively.