Phase 1 - Compost ↓

To grow quality mushrooms, it all starts with making high quality mushroom compost which takes passion, attention to detail and an understanding of chemistry and biology. Mushroom compost is made up of 4 essential ingredients:

· Wheat straw

· Chicken manure

· Gypsum

· Water

These ingredients are chemically analysed to make a recipe that balances carbon and nitrogen as well as moisture and pH. These ingredients must be thoroughly blended to create a completely homogeneous blend, which contains 75-76% moisture. To ensure the compost is of best quality, it must remain aerobic. This is done by placing the mixed compost on a high pressure aerated floor, which blows air though the compost. The natural decomposition process raises the temperature of the compost to 80’C which takes place in concrete bunkers.

After the compost has been through the phase I process, it is analysed to ensure it has broken down sufficiently. It is then transferred into the tunnel facility to commence the next stage of the process, phase II.

Phase II - Spawning ↓

The tunnel facility is a purpose-built facility for handling and processing mushroom compost. It is known as a tunnel facility due to the long stainless-steel climate-controlled chambers inside, called tunnels. The phase I compost is filled into the tunnels onto a strong pulling net using a telescopic conveyor called a filling cassette. The tunnels are equipped with a low pressure aerated grid floor with a plenum chamber underneath that forces air through the compost. Once filled, the tunnel is sealed and the climate units are turned on.

Now the compost is allowed to raise to a temperature of 60'C for a period of 10 hours, this process is known as pasteurisation. This step is critical as it kills of bad bacteria, spores, moulds or other potential competitors to mushrooms. The air temperature is then lowered and the compost is therefore cooled down to 48’C for 4 days before finally lowering it again to 25’C ready to be inoculated with mushroom spawn. Mushroom spawn is produced in specialised laboratory, where the mushroom spores are inoculated on to a sterile grain seed, such as Rye. These spores grow mycelium which is the foundation of the mushroom.

Before the tunnel is opened it is essential that the hall where the work is carried out, known as the spawn hall is meticulously cleaned to ensure no disease can get into the pasteurised mushroom compost. The hall is then pressurised to keep airborne contaminates out.

The phase II compost is pulled out from the tunnel using a specially built tunnel winch, which pulls the net from the tunnel. After the compost has had spawn added to it, the compost is transferred into another sterilised stainless-steel insulated tunnel where the mycelium will grow and colonise the compost for the next 2 weeks.

Phase III - Casing↓

The mushroom compost is now ready to be transported to the mushroom farm and our customers. The compost is emptied from the tunnel using the tunnel winch into the trucks.

Once arrived at our family farm Pure Mushrooms, the compost is filled into the growing trays with a layer of peatmoss on the top.

The trays are transferred into the fully climate controlled growing rooms, where it takes up to 17 days before the mushroom harvesting can start. Each square meter will grow up to 35kg of mushrooms over 2-3 flushes. Once the final flush is harvested the room is “cooked out”. Steam is injected into the growing room where it remains at 70’C for 8hrs to sterilise the compost. The trays are then emptied and the compost and peatmoss are sold as soil conditioner to gardening and landscaping companies.

Phase IV - Growing↓

The growing rooms are equipped with sophisticated sensors and computer software to monitor and control the climate inside the rooms in order to ensure optimum conditions are maintained for mushroom cultivation. After the compost has been through all of the machines the mycelium is damaged and needs time to be repaired, which is the first stage in growing, called mycelium recovery. After the 5 day recovery and mycelium growing period the air temperature is lowered and fresh air (higher oxygen air) is added to the growing room, which is known as airing. The mycelium will stop growing and knit together which forms tiny mushrooms, called "pins". The development of these pins into fully formed mushrooms is directly influenced by a perfect balance of the climate in the room, such as air temperature, carbon dioxide (CO2), relative humidity and moisture deficit/evaporation. Mushrooms do not grow by photosynthesising and therefore do not need light to grow. The grower must carefully change the conditions (the parameters listed above) for several days to stimulate the formation and growth of different pins at different times, this practice is known as sizing stagger. This stagger is essential for getting the best quality, the highest yield as well as the easiest harvesting of the mushrooms.

Phase V - Harvesting↓

As soon as some of the mushrooms have grown to approximately 40mm in diameter, the air temperature is steadied around 18'C with a relative humidity of 90%. The trained mushroom pickers can start harvesting the first mushrooms. When the climate is ideal mushrooms double in size every 24hrs. Therefore the pickers are able to continually pick only the correct sizes, knowing that the mushrooms that might not be ready to pick now, will be ready to be picked by the end of the day. Our pickers are trained to strategically select certain mushrooms, to fulfil the orders of our valuable customers. For example, at times there might be a demand for large open mushrooms, these are simply mature mushrooms. The pickers must create space around selected mushrooms to allow them to fully develop. Each flush is harvested over approximately 5 days before all mushrooms are picked off. The climate is changed and is now ready for the next flush.

Mushroom Cultivation is a True Profession↓

Mushroom farms and compost yards have a very high capital investment and like other food producing industries are exposed to risk of pest and disease. This can potentially cripple the businesses to grow consistent yield and consistent quality all year-round, year after year. The compost and peatmoss are natural products and vary through seasons and years. The outside weather conditions vary from extreme dry heat, to cold wet winters therefore vary these natural products and needs to be carefully monitored by the grower. The grower must adapt to all of these variables in order to maintain quality and yield, while also sustaining a stringent hygiene program to prevent pests and diseases.