Yoghurt is produced by lactic fermentation. The process is very similar to the one used for making beer, wine and cheese - in each case, beneficial organisms transform a basic ingredient via a process known as fermentation.
Fermentation is a process that naturally extends the shelf life, notably thanks to the presence of lactic acid produced during the fermentation process. It is the lactic acid that gives the recognisable sour taste in yoghurts, and acts as a natural preservative.
Fermentation also has other advantages such as the addition of organoleptic properties (taste, flavour, texture and consistency), improving the nutritional quality, and enhancing the digestibility of the milk and the better assimilation of minerals naturally present.
- This high heat treatment allows the proteins to form a gel and also removes any harmful bacteria in the milk and provide a better environment for the starter cultures to grow.
- Milk is pasteurized before the starter cultures are added.
Adding the microorganisms
- As the bacteria grow and multiply, they transform the milk sugar, lactose, into lactic acid, which in turn acts on the milk proteins, which then solidify and coagulate.
- Streptococcus thermophilus hydrolyses the milk proteins and contributes to the unique aroma, texture and flavour of yoghurt.
- This process of fermentation thickens the milk into yoghurt, giving it its characteristic custard-like texture and its tangy taste.
Fruits, flavours and other ingredients can be added to the yoghurt at various points in the manufacturing process depending on the type of yoghurt.
Other varietiesThis manufacturing process is identical for all types of yoghurt, only the source of milk changes. The manufacture of other fermented milks also follows the same type of process, again only the starter cultures and fermentation parameters are different (temperature, time ...).