Bacteria Ferment Milk to Produce Yoghurt

Question 1

What is fermentation?

Answer 1

When microorganisms break sugars down to release energy - usually by anaerobic respiration

Question 2

What is yoghurt basically?

Answer 2

Fermented milk

Question 3

1) why is the equipment sterilised?

Answer 3

To kill off any unwanted microorganisms

Question 4

2) why is the milk pasteurised (heated up to 72°C for 15 seconds)?

Answer 4

To kill any unwanted microorganisms

Question 5

3) what is then done to the milk?

Answer 5

It is cooled

Question 6

4) what is added?

Answer 6

Lactobacillus bacteria

Question 7

5) what is then done to the mixture?

Answer 7

It is incubated

Question 8

6) what is it incubated in?

Answer 8

A vessel called a fermenter

Question 9

7) what does the bacteria ferment and what does it form?

Answer 9

The lactose sugar in the milk to form lactic acid

Question 10

8) what does lactic acid cause the milk to do?

Answer 10

Clot, and solidify into yoghurt

Question 11

9) what is done last?

Answer 11

Flavours and colours are sometimes added and the yoghurt is packaged