Lesson 8 - Yeast

Question 1

Name the 4 parts of a yeast cell and there function

Answer 1

1. Cell Wall/Membrane - surrounds the yeast cell and provides strength. Membrane controls everything to leave and enter the cell
2. Nucleus- contains the cells DNA which has 16 chromosomes.
   3 Mitrochondria - site of reactions that produce energy.
3. Cytoplasm- fluid in the cell which stores materials

Question 2

Describe how and the steps of yeast Growth

Answer 2

Yeast grows by budding mechanism.

New cells form when the mother’s cell wall is partially broken which allows for a bud to form.

The bud grows gradually forming the cell components. Which eventually separates from the mother. Leaving scars on both bud and mother.

Question 3

Name the three types of yeast

Answer 3

Creamed

Pressed

Dried

Question 4

How is cream yeast stored

Answer 4

Deliverered in tankers and stored in bulk tanks onsite. This is at around 3-4 c

Question 5

How is pressed yeast stored

Answer 5

Supplied in 25 kg bags. And stored at 3-4 c. Has a shelf life of around 2 weeks

Question 6

How is dried yeast stored

Answer 6

Delivered in packs at ambient temps. Has a shelf life of 3 years

Question 7

Describe the difference between culture and wild yeast.

Answer 7

Culture. - Yeats grown in a commercial setting in sterilise conditions to prevent contamination.

Wild yeast. - mixture of yeast and bacteria. Very unpredictable however can contribute to different flavours and is cheap