Yeast and Bacteria Flashcards
What is pitching or inoculation?
The process of adding cultured yeast to the wort.
What are the two different origins of yeast?
Cultured or Wild
What 3 things does the choice of yeast strain influence?
1) The type of aroma created.
2) The amount of aroma created.
3) The sweetness of the final beer.
What’s ale yeast called?
Saccharomyces cerevisiae
What temperature does ale yeast ferment at
Warmer (18 - 24 Degrees C)
How long does Ale yeast take to Ferment?
3 - 5 days
What are the 6 example ale yeast strains
Abbey Ale Yeast, Saison Yeast, Witbier Yeast, Weizen Yeast, British Ale Yeast and American Ale Yeast
What’s lager yeast called?
Saccharomyces pastorianus
What temperature does lager yeast ferment at
Colder (7 -15 degrees C)
How long does lager yeast take to Ferment?
7 - 14 days
How many Ale yeast strains are there?
1500 - 2000
How many Lager yeast strains are there?
approx. 150
Esters give you …..
Fruity Aromas
Phenols give you …..
Spicy Aromas
What is Brettanomyces? (Brett)
It is a type of Yeast
What complex flavours does Brett Yeast add?
Fruity esters (ripe pineapple), stone fruit (peach) and farmyard notes (hay, horse blanket, earth or leather)
What general style of beer is made when using Brett Yeast?
Beers with low or imperceptible sweetness.
Lambic styles are often influenced using Brett as well as lactic acid bacteria.
What is the most common type of bacteria used in beer production?
Lactic acid bacteria
What does using lactic acid bacteria give to a beer?
Acidic notes as well as aromas of yoghurt/kimchi or sour fruits
Apart from Lactic acid bacteria, name another style of bacteria used in beer production?
Acetic Acid Bacteria
What flavour and aroma can acetic Acid Bacteria give to a beer
It can give the flavour profile of vinegar
Do you want high or low levels of acetic acid bacteria in the beer
Low levels, as it can add complexity
What beer is known to use acetic acid bacteria in the production process?
Flanders’s red
