5.7 understand the role of bacteria (Lactobacillus) in the production of yoghurt

Fermentation is where microorganisms break sugars down to release energy - usually by anaerobic respiration.
Production of yoghurt:

1. All equipment is sterilised to kill of any unwanted microorganisms
2. The milk is pasteurised at 72C for 15 seconds to kill of any unwanted microorganisms. The milks then cooled.
3. Lactobacillus bacteria are added and the mixture is heated to about 40C in a fermenter.
4. The bacteria ferment the lactose sugar to form lactic acid
5. Lactic acid causes the milk to clot and solidify into yoghurt
6. Flavours are added and it's packaged.