Large Scale Microbe Production

Microbes and nutrients are put into the fermenter and air is bubbled through so that the microbes can respire aerobically. As carbon dioxide builds up the gas outlet releases it to avoid build up of pressure. A water jacket surrounding the fermenter maintains an optimum temperature so the proteins do not denature. The product is run off from the bottom. It is separated from the microbes and purified so that it can be sold or distributed.

Temperature, pH and oxygen probes are linked to a computer which monitors the conditions inside the vessel. Paddle stirrers ensure that the microbes, nutrients and oxygen are well mixed and distributes the heat evenly.

Poor temperature control often results in fermentations that are too hot, causing the yeast to become too sensitive to alcohol toxicity (meaning that they will die off from the alcohol before their usual tolerance is met).

Mycoprotein is made in 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 constantly monitored to maintain the optimum growth rate.

The organism and nutrients combine to form Mycoprotein solids and these are removed continuously.

Once removed the Mycoprotein is heated to 65°C to breakdown the nucleic acid.

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.