Term
| Temporary hardness removal |
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Definition
| Boiling will precipitate calciumm bicarbonate, which will not go back into solution, but rest on the bottom of the hot liquor tank |
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Term
| do you want low or high MW (molecular weight) protein for a good head |
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Definition
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Term
| describe fusel alcohol character formed during fermentation |
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Definition
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Term
| describe ester character formed during fermentation |
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Definition
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Term
| describe diacetyl character formed during fermentation |
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Definition
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Term
| What is and when does high croissen occur? |
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Definition
| the foam at the top of the fermenter during log phase |
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Term
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Definition
| the highly bitter croissen, filled with hop resin and alpha acids found at the top of beer during log phase |
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Term
| what is a uni-tank fermenter used for? |
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Definition
a) fermentation
a.1) transer yeast away from beer
b) maturation |
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Term
| What happens during each of the 3 phases of fermentation? |
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Definition
1) lag phase: 3 days, active yeast growth, intense metabolic
activity, esters and diacetyl precursors formed
2) log phase: High temperature to maintain fermentation speed,
remove volatile compounds, convert acetaldehyde to ethanol,
and speed reduction of diacetyl. High pressure with high CO2 saturation lowers yeast
metabolism, ester formation, and fusel alcohols
3)Cooling, creating chill haze and carbonation |
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Term
| What is the difference between sanitizing, disinfecting, and sterilizing? |
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Definition
Sanitizing - Decrease bacteria - Eliminate ‘beer spoilers’
Heat and/or sanitizers
Disinfecting – Destroy micro-organisms,but not spores
Higher intensity heat and/or sanitizers
Sterilizing - Destroy ALL Organisms |
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Term
| diacetyl and DMS are measured in what unit? |
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Definition
| ug/l (ppb) (the book is wrong in stating mg/l per lyn) <100ppb recommended at ferm end |
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Term
| describe how glucose becomes ethonal |
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Definition
glucose (6Carbon) >
glycolysis (loses NAD)>
pyruvate (3carbon) [is the building block to make all the parts]>
acet + CO2 (to get NAD back) >
ethonal |
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Term
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Definition
k = adding wort back
c = braun hefe |
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Term
| why would you increase temperature setpoint on a fermentor halfway through conversion? |
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Definition
| speed up diacetyl absorption by yeast |
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Term
| how would you check diacetyl without a GC? |
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Definition
take sample from fermenter
remove yeast
split into 2, put one in fridge
heat to 60C for 30min
cool and taste (this tells you
if no butter, then no DMSP or DMS
if butter, then compare to refrigerated control. |
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Term
| what causes colloidal instability? |
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Definition
- charge tannins (polyphenols)
+ charge protein |
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Term
| if you use whole or type 90 hops, what affect on colloidal stability will occur? |
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Definition
| all the polyphenol content is entering beer, increasing haze |
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Term
| if you use whole or type 90 hops, what affect on colloidal stability will occur? |
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Definition
| all the polyphenol content is entering beer, increasing haze |
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