Microbes and food 3. Food producers
Selection of food photo
Picture 3.1a A selection of foods made with microbes.

3.1 What do food producers do?
For thousands of years humans have taken advantage of natural fermentations to make alcoholic drinks, bread, dairy products and pickles, although no-one understood that microbes were responsible for these processes until recently. Fermentation not only gives food a good taste, texture and smell, but it causes changes that inhibit the growth of undesirable food microbes, improving its storage life and safety. Nowadays fermentations are used to make an amazingly wide range of food and drink. Microbes are involved in the production of foods in other ways too, and without their help our diet would be very dull indeed.
Vinegars photo
Picture 3.2a Vinegars and pickles rely on fermentations.

3.2 Fermented foods

Microbes break down complex molecules in food to provide the energy for their growth. As by-products they sometimes produce the fermented foods and drinks that we enjoy.

For many years fermentation was a hit and miss process which relied on naturally occurring microbes getting into our food. For example, yeasts in the air would land in fruit juice and ferment the natural sugars in it, producing wine.


Microbes and fermentation are now better understood and each process is carefully controlled from start to finish. Special cultures of microbes are used in the fermentations to give the product the required properties. Two main types of microbes are used to make fermented foods, either separately or together:

Moulds sometimes also play a part in the fermentation process.