Mycoprotein is made in 40 metre high fermenters which run continuously for five weeks at a time.
The fermenter is sterilised and filled with a water and glucose solution. Then a batch of fusarium venenatum, the fungi at the heart of Mycoprotein, is introduced.
Once the organism has started to grow a continuous feed of nutrients, including potassium, magnesium and phosphate as well as trace elements, are added to the solution. The pH balance, temperature, nutrient concentration and oxygen are all constantly adjusted in order to achieve the optimum growth rate.
The organism and nutrients combine to form Mycoprotein solids and these are removed continuously from the fermenter after an average residence time of five to six hours. Once removed the Mycoprotein is heated to 65°C to breakdown the nucleic acid. Water is then removed in centrifuges, leaving the Mycoprotein looking rather like pastry dough.
The Mycoprotein is then mixed with a little free range egg and seasoning to help bind the mix. It is then steam cooked for about 30 minutes and then chilled, before being chopped into pieces or mince.
The product is then frozen. This is a crucial step in the process because the ice crystals help to push the fibres together, creating bundles that give Mycoprotein its meat-like texture.
The pieces and mince are then sold under the Quorn™ brand and also in wide array of products ranging from escalopes to ready meals, deli slices to sausages.