Section 2: Brewing Flashcards
0
Q
Describe diacetyl
A
- buttery movie theater popcorn, butterscotch
- present at low levels in some English style ales
- common in dirty draft lines
- bacterial contamination
- leaks out of yeast cells during amino acid synthesis
1
Q
Name the major steps in the brewing process
A
- Milling
- Mashing
- Lautering
- Boiling
- Whirlpooling
- Cooling
- Fermenting
- Maturing
- Filtering
- Packaging
- Distribution
2
Q
Describe Estery/ Solvent (ethyl acetate)
A
- fruity, nail polish remover
- created in boil
- brew house probs
- microbial infection
- found in high alcohol beer
3
Q
Describe Estery isoamyl acetate
A
- Banana, circus peanuts
- sign of yeast stress
- found in high alcohol beers
- ford during fatty synthesis
- common & desired in Bavarian weizens
4
Q
Describe 4-vinyl guaiacol
A
- clove, phenolic
- only in German weizens
- formed during fermentation if ferulic acid was formed durning malt kilning
5
Q
Describe 4-ethyl phenol
A
- “barnyard”/ Brett
- horsey
- appropriate in lambick, English style old ales and some saisons
- made by Brettanomyces yeast
6
Q
Describe acetaldehyde
A
- green apples
- should NEVER be detected
- symptom of too young “green” beer
7
Q
Describe butyric acid
A
- rancid butter
- should NEVER be detected
- in spent grains
8
Q
Describe isovaleric acid
A
- rancid butter
- should NEVER be detected
- in spent grains
9
Q
What is Brettanomyces and what does it do?
A
- yeast strain
- role in lambic, some saisons, and traditional English old ales
- barnyard aromas
- metabolizes maltose
- can be used to slowly ferment beer
10
Q
What are pichia and candida?
A
- type of yeast
- similar to sherry
- minor role in lambics
- occurs as spoilage organism
11
Q
What are lactobacillus and pediococcus?
A
- types of yeast
- sours lambics and Berliner Weisses
12
Q
What is acetobacteria?
A
- type of yeast
- vinegar and pickle aromas
- common in oak aged beers
- important aromas of lambics➡ Flanders style red/ brown ales
