Agaricus Bisporus was the first mushroom to be cultivated for commercial use and is still today the most commonly grown. In the 17^th Century France the first mushroom ‘farms’ were started up just outside of Paris. Today mushroom farming is a very sophisticated and highly technical business that has spread around the world into a vast international industry.

Mushroom Farms consist of large, dark, climate controlled rooms in which the mushrooms are carefully cultivated. To produce mushrooms, spores are collected in laboratories and used to inoculate grain that then becomes the spawn. It is from this spawn that the mushrooms are grown.

One of the most fundamental elements of growing a top quality mushroom is the compost. The compost is the medium in which the mushrooms will grow and it is from this that they will get all their nutrients. Preparation of compost takes on average between two and three weeks. Once it is ‘composted’ sufficiently it is placed in large trays and put into the peak heat rooms.

In these the temperature is increased over a period of days and the compost is pasteurised. It is then dropped back to a sustainable level conducive to growing, removed from its trays and mixed with the spawn. The trays are then re-filled and placed in ‘Spawn Running Rooms’. These rooms are carefully monitored with the heat and humidity being controlled by the growers.
During spawn running the compost becomes filled through with what looks like spiders webs or a very fine lacy structure that runs throughout the compost and is known as ‘mycelium’.

After almost two weeks of being left to grow, the compost is again removed from the sheds and still in its trays another layer is added. This layer of casing is a thin layer of peat moss. It is this that actually provides the environment for the mushrooms to develop from the mycelium stage into mushrooms.
Once the casing has been added the trays are placed back into growing rooms. Over the next 18 or so days the mushrooms begin to develop. Tiny white protrusions start to show through the casing. These are about the size of small pin heads to start with but each of these will grow into a mushroom.
Mushroom growing is a cyclical process. Each ‘crop’ that comes through is referred to as a ‘flush’. A shed with one lot of compost can produce up to and more than five flushes but each consecutive flush takes a little bit longer to come through and yields less than the last.
During the growing cycle the temperatures, air flows and humidity are carefully and constantly monitored. Each of these can have a dramatic impact on the product quality and shelf life. The mushrooms are picked when mature and unlike some produce, size is not a factor of maturity. Their actual size when mature may vary greatly. This too can be affected by the growing process.
Both the white and brown buttons are grown in this way. What is often not realised is that a large Flat is actually just a brown button that is older and has been grown specifically to this size.
Following harvesting all the trays are removed from the sheds and are emptied and steam sterilised before the process is repeated. It is an extremely labour intensive process that requires a great deal of careful planning if there is to be a consistent supply of mushrooms available. From starting to make the compost to harvesting the first flush takes around eight weeks.
At Meadow Mushrooms Ltd we produce our own spawn and our own compost which gives us an advantage of being able to better control our production. Many other farms buy both of these components from other producers..