Exam 3 Flashcards
1
Q
Malting definition
A
Germination and drying under CONTROLLED conditions resulting in malt/malted cereal
2
Q
Brewing definition
A
Action of yeast fermentation on malted cereal
3
Q
Reason small breweries died out
A
- Pasteurization and refrigerated transport
- Milwaukee producers ‘boom’ (Millers Busch, budlight all got big at the same time)
- Prohibition
- effective canning technologies
4
Q
Light Beer definition
A
Reference to caloric content (1/3 reduction at least)
5
Q
Pale, Amber, and Dark beer refers to
A
color
6
Q
Ale - definition
A
Top Fermented
often cask conditioned after it has been produced
Germany
7
Q
Lagers
A
Bottom Fermented
Aged (lagered)
Austria
8
Q
Malting goal
A
uniform and complete modification of the endosperm
9
Q
Malting results/yields
A
Enzymes and soluble fermentables
Color and flavor
Friability
10
Q
This plant hormone signals the scutellum to produce enzymes to break down cell walls and endosperm during germination
A
Giberick acid (moves in a wave across the seed)
11
Q
Malt quality control is highly dependent on the __
A
variety
12
Q
Different cereal varieties (malting) can have differences in what factors that would effect the malt quality
A
Percent germination (want highest possible)
enzyme levels
extract %
13
Q
Extract percent (malting quality)
A
Ability to modify the endosperm
14
Q
Dormancy - definition
A
lack of germination, under germinative conditions
- common in all cereals
- must know dormancy of a grain and break it before starting malt process
15
Q
After-ripening is key to preventing these malt quality issues
A
-Poor endosperm modification
-hazy wort
-lower solubles extracted
-very high viscosity of the extracted soluables making for hard processing
(*generally 3 month minimum post harvest)
16
Q
Malting process steps
A
Grading
Steeping
Germination
Kilning
17
Q
Grading step
A
size, then malted according to shape, need uniform shapes for a uniform malt
- plumper = brewers malt
- smaller/thinner = distillers malt
18
Q
Steeping (hydration) step goals
A
Get kernel to 43% moisture (not shriveled, not blown up)
- evenly distributed moisture
- hydrostatic and osmatic pressure equiliberated
19
Q
Factors affecting steeping rate and time
A
- Variety
- Plumpness
- Temperature and rate of aeration
- Final product moisture
- distillers higher 47%, brewers lower 43%
20
Q
Steeping process steps
A
- Barley in excess water at 15 C
- Air pumped through steep water (keeps anaerobes down, keeps pH up)
- After 12-24hr steep water drained
- Air rest (with turning)
- Repeat until target %M (usually 3 stages)
21
Q
Under steeping results in
A
Too dry poor enzyme production poor endosperm modification low extract **Therefore reduced yield to make beer with
22
Q
Over steeping result in
A
Delayed germination
Mold and bacterial growth
off odors and flavors
23
Q
How is mold controlled during malting steeping
A
multiple changes of clean water
air pumping
turning grain during air rest
24
Q
Germination goals
A
Maximum enzyme production (alpha and beta amylases, beta glucanase)
25
Germination controlled by
temperature
water concentration
oxygen concentration
Variety ***biggest one
26
Germination process
```
Steeped barely in 1-2meter thick layer
cool water saturated with air is circulated
grain bed turned frequently
acrospire length is monitored
Product = GREEN malt
```
27
Green malt characteristics
result of germination
high in enzyme activity
low in storage stability
28
Kilning definition and goals
* Controlled drying*
- stops germination
- Primary goal: stabilizes malt to storage level while keeping max enzyme activity
- Secondary goal: color and flavor development (at expense of enzyme activity)
29
Kilning steps
- Controlled temp increases (dry to 5.5% moist)
| - Malt experiences higher temps as it dried
30
Why do we slowly increase temps during kilning and what is the result in the malt characteristics
Enzymes are more stable at lower temperatures and lower moisture. So we dry gently until reach a lower moisture, then can use higher temps to give color and flavor (can kiln for darker colors here)
31
Long cool drying during kilning results in what color and enzyme activity
pale malt
high enzyme activity (maybe a dry flavor bc?)
(in practice multiple malts used for final product)
32
Rapid hot drying during kilning results in what color and enzyme activity
Dark malt
low enzyme activity
(in practice multiple malts used for final product)
33
Diastatic malt definition and uses
still retains enzyme activity
| brewing and distilling, baking
34
Non-diastatic malt definition and uses
has not retained enzyme activity
| flavoring (ready to eat breakfast cereals)
35
Malt provides what to brewing process
- Fermentable carbohydrate source
- enzyme source
- color, flavor, foam/head
36
Adjunct provides what to the malt and its benefits,
| what is typically used
* it is not required for brewing*
- less expensive source than malt of CHOs
- bland (don't want extra flavors)
- low in lipids
- allows lighter beers to be made using unmalted cereals
- commonly used: corn, rice, high DE glucose syrups
37
Hops do what for brewing
flavor
aroma
clarity
microbiological safety
38
Hops processing after harvest and why
-Must be dried or extracted immediately after harvest. (extracted using CO2 under conditions that make it liquid)
To preserve or isolate functional compounds
39
What are the brewing prinicpals from hops and where are they located in the cone
Concentrated in luplin glands
- Essential oils
- Bitter resins (alpha and beta acids)
- Polyphenols (tannis)
Composition varies by variety
40
Hop resin characteristics and provide what to beer
Unique to hops, extremely powerful
-provide bitterness
Alpha acids = primarily bittering
beta acids= microbial inhibition
41
Essential oils in hops provide what to beer
Provide aroma and flavor
| -some are volatile and will be in the head space above a beer
42
Polyphenols in hops do what in brewing
Tannins
| react with and precipitate protein
43
Waters role in brewing
Cooking medium, solvent
44
pH of water affects and the optimum level
(optimum is 5.0-5.2)
- max sugar production
- max bitterness from hops
- max protein coagulation
45
Minerals in water effect what in brewing
Flavor- masking or enhancing
enzyme activity
protein solubility
46
Minerals in brewing, what we want and don't want
Sodium chloride want for taste. Less = a lighter taste
Keep out
-Iron (catalyzes oxidative reactions, gives off odors and flavors)
-Nitrates (kill yeast)
47
Solution to poor water at brewing site
ion exchange columns and charcol filters
48
Yeast strains used for brewing
```
Sccharomyces pastorianus (lagers) and S. cevevisiae (ales)
Many strains exist.
```
49
Yeast vigor
How vigorously in converts CHOs to ethanol, produces CO2 and secondary flavor components
50
Yeast flocculence
Rates and extent of aggregation
- consequence of movement away from fermentable CHOS, metabolism slows and stops
- affects attenuation
51
yeast attenuation
Degree/extent of conversion of CHOs to alcohol
| -function of yeast type and brewing process
52
Rapid yeast flocculence does what to attenuation and therefore the beer
Rapid decrease in metabolism
-High residual CHOs - low attenuation
Beer= sweet, full mouth feel (heavy)
53
Slow yeast flocculence does what to attenuation and therefore the beer
Delayed reduction in metabolism
- Low residual CHO - high attenuation
- beer= dry and light mouth feel
54
Why do s. cervisiaes top ferment
trap CO2 as they flocculate and rise to the top
- fast floc. low atten.
- ales
55
Why doesn't bakers yeast work for brewing
No aggregation, little to no floc.
56
Brewing process steps
```
Malt milling
adjunct cooking
mashing
wort isolation
hopping / boiling and straining
cooling
pitching
fermentation
yeast separation
finishing
```
57
Mill the malt to what size
Endosperm to small particle size (want it friable to come apart easily)
hull in large pieces
58
Adjunct cooking goals
starch gelatinization
protein denaturation
thinning
kill mircrobes (first sterilization point)
59
How to cook adjunct
Adjunct + water + part of rested malt
-Acid pH
Heat increased over 2hrs with stirring
60
Mashing purpose
Starch conversion to fermentables
| enzymes are acting on the mash converting CHOs to glucose chains of 3 or less
61
Mashing result
```
Soluables = wort
insoluables = spent grain, insoluable protein and nonstarch polysacc.
```
62
Mashing process
Cooked and cooled adjunct added
entire system heated and stirred gently
enzymes are acting on the mash converting CHOs to glucose chains of 3 or less
63
Wort separation is a critical step because
- amount of wort affects process and results
| - problems with filtration / sep. will complicate the process
64
Wort separation products
```
Sweet wort (#1) -(oulables)
brewers spent grains
```
65
Sweet wart
product of wart seperation
| 85% CHO conversion
66
Wort sep. methods
Thin-bed filter = plate and frame filtration
Centrifugal / whirpool = continuous process
Sparging = flushing with water until water ~1% solids
Lauter Tun = tradition batch process using hull bed as natural filter
67
Hopping goals
-Sterlization
Extraction of hop principalsl
removal of some protein
68
Hopping process
Hops added in single or multiple additions
Dry hopping or extract
double dry hopping = as dry intact cones
69
First addition of hops in double hopping
Get tannins to complex with protein, float to top in a foam = hot break, is removed
Bittering
Oils are lost bc they are volatile
70
Second addition of hops in double hopping
Near end of the boil
after hot break
flavor and aroma hops
71
Result of hopping / boiling / straining and characteristics
Bitter wort is darker, anerobic, sterile
72
bitter wort cooling purposes and steps
- keep yeast alive
- refridgerate
- oxygen sparging (pumped through) produces cold break to remove more tannin protein complexes
73
Pitching -def and steps
Yeast addition
- oxygen pumping dramatically accelerates growth and metabolism
- pumped to fermentation tanks
74
Fermentation
- how long
- produces what
- what is key to control and why
Most action in first 3-4 days but goes up to 9 days
Yeast lost to flocculation
CO2 is produced and captured
Temp control is key to prevent yeast inactivation, runaway ferments, and off-flavor metabolites
75
Krausen
Blocky head formation on the fermt after 2 days
- Hop resins, tannin-protein complexes, CO2
- is skimmed off
76
Yeast separation techinique by type
Lagers - top pumping
Ales- skimming
About 4x amount as original
77
Fate of separated yeast
Can be used in next batch about 4 times ( don't want other strains developing)
Co-product
78
Finishing
```
Beer is chilled
Aging dependent on beer type and packaging
chill-proof
final filtration
adjust carbonation
Pasteurize if bottled or canned
Package
```
79
Lagering
Partial recarbonation
| extended bulk cold storage (12weeks)
80
Cask conditioning of ales
Barrel storage with residual yeast - secondary fermentation
| proteins precipitating out, sharp flavors being removed
81
Distillation grains define
the end product
barley = scotch
corn - bourbon
82
Distillation steps
```
Adjunct cooking and cooling **no malt**
mashing
fermentation
dsitillation (2x in some cases)
blending
aging
bottling
```
83
Cooking process in distillation vs brewing
More severe process - hot and high pressure
no malt
completely paste the starch
84
Fermentation process in distillation vs brewing
```
Different yeast
higher temps
shorter ferment 3-4days
whole mash, no worst seperations
bacterial innoculum optional to give sour mashes
```
85
Distillation step process
Entire fermented mash in the still
heat and trap volatiles in a condensing column
usually more than one still "pots"
86
Extent of distillation
Based on ethanol present
87
Aging in distillation -purpose - time required
critical step
aging smooths and mellows and develops flavors
Years rather than months like beer
88
Whiskey blending
Heavy with light flavored whiskeys to get consistency
89
Distillation flavor due to
```
Type of grain used
Type of malt
innoculum or not (sour mash)
-set of the still (range of volatiles taken off= the art)
length and type of aging
blending or not
```
