1. Yeast Biology

2. General Biology Living Organism Classification- Taxonomy
3 Domain System 5 Kingdom System

3. What is a CELL? Cells are the “basic unit of life”
Cells can live on their own, reproduce and do all the processes living things do
Single cell organisms, like: bacteria and yeast
Multicellular organisms, like: plants and animals

4. What is a CELL? What are the 3 main parts of a cell? 1. Cell membrane
2. Nucleus
3. Cytoplasm

5. What is a CELL? Cell (plasma) membrane
The cell wrapper made of mostly lipids (fats)
This wrapper has control over many important functions, including what goes in and out of the cell

6. What is a CELL?
Nucleus
Primarily made of DNA/chromosomes/genes-- the so-called
“genetic material”
The genetic material is essentially the ‘recipe’ to make other cell parts, cell products (like ethanol in yeasts), and entire cells, for that matter
nucleus

7. What is a CELL? Cytoplasm The water part of the cell
Also contains organelles -- structures that have specific functions
The fermentation chemical reactions occur our here

8. What is a CELL? Cytoplasm
Organelles -- structures that have specific functions
Rough endoplasmic reticulum (ER): site of protein production.
Smooth ER: site of lipid or fat production.
Mitochondrion: site of energy production. Vacuoles: sacks of any kind of product or water.

9. What is a CELL?
Smooth ER
Rough ER
Mitochondrion

10. What is a CELL?
Cell Wall
An additional structure, external to the cell membrane
Most bacteria have cell walls
All yeast have cell walls. (Animals like us and dogs, do not have cell walls.)
Cell walls give the cell extra protection and structure- like an external skeletal system.
Chemicals can go in and out of cell walls.

11. Asexual Sexual Cell Reproduction- 2 types Only 1 Takes 2 Goal
Fast
Simple
However, . . .
Sexual
Takes 2
More lengthy in time
More complicated
More potential problems
Goal
However, . . .

12. Sexual Asexual Cell Reproduction- 2 types Plants Bacteria Fungi
Animals
Some Protists
Asexual
Bacteria
Brewing/Distilling Yeast
Some Protists

13. What is a yeast cell? Single cell organism Member of Fungus Kingdom
Some yeasts cause human/animal diseases
Yeasts are used to ferment alcohol: wine, liquor and BEER!
Yeast can also be used to bake– the CO2 causes bread to rise

14. What is a yeast cell?

15. The 2 basic brewing yeast types: Ale Yeasts and Lager Yeasts
Ale yeast species is Sacchromyces cerevisiae
Lager yeast species is Sacchromyces pastorianus
Sacchromyces, literally means, “sugar fungus”

16. The 2 basic brewing yeast types: Ale Yeasts and Lager Yeasts
Ale yeast species is Sacchromyces cerevisiae
Classic, ‘natural’ brewing yeast
Ferment at higher temperatures
Produce more complex flavor compounds
-esters
-phenols
Lager yeast species is Sacchromyces pastorianus
Developed in lab at Carlsberg Brewery in (Saccharomyces carlsbergensis) 
Ferment at lower temperatures
Produce less complex flavor compounds

17. Yeast REPRODUCTION
Brewing yeast reproduce asexually: they essentially make an exact copy of themselves…called BUDDING
Yeast will start reproducing after being ‘pitched’ into the wort. (there is not enough yeast to eat up all the s-sugars)
They need to reproduce so they can eat up all the simple sugars to produce as much ethanol as possible
Bud (new ‘baby’ yeast cell)
Parent yeast cell

18. WHY WE ADD O2 BEFORE FERMENTING
BREWING CHEMISTRY
C6H1206 → C2H5O + CO2
ENERGY FOR REPRODUCTION

19. WHEN (EXACTLY) DO WE ADD O2 BEFORE FERMENTING?
BREWING CHEMISTRY
TO CHILLED WORT