Fermentation Principles Overview Exam Questions with Correct Answers 100% Pass
Fermentation - Answers Yeast growth on wort, converting extract into alcohol and CO2
Industrial Fermentation - Answers Controlled conversion of wort into beer by yeast and possibly other
microorganisms
Alcohol (Ethanol) - Answers Product of fermentation process
How is fermentation monitored - Answers Decrease in wort gravity by a hydrometer or densitometer
How does yeast adjust during the lag phase - Answers Yeast adjusts its physiology in response to being
moved from starvation conditions to growth conditions.
What happens to yeast during the lag phase? - Answers Yeast takes up oxygen, breaks down glycogen,
and synthesizes essential membrane lipids, sterols, and unsaturated fatty acids.
What is the outcome of the lag phase in fermentation? - Answers The yeast is prepared to grow and
convert extract into alcohol and CO2 during fermentation.
What characterizes the Log Phase in brewing? - Answers Wort gravity decreases at the maximum rate,
controlled by various factors.
What controls the rate of wort gravity decrease in the Log Phase? - Answers Initially, the rate is
controlled by pitching rate and wort oxygen levels, then by temperature.
What reaches their maximum levels during the Log Phase in brewing? - Answers Rates of CO2 formation,
alcohol, and yeast concentration.
Deceleration Phase - Answers Yeast stops multiplying, wort gravity decrease slows. Occurs due to
running out of essential nutrient, or alcohol too concentrated.
What happens during the stationary phase? - Answers Cells return to starvation state, constant wort
gravity.
What is the relationship between cell growth and cell death in the stationary phase? - Answers Rate of
cell growth equals the rate of cell death.
What do brewers monitor to track the progress of fermentation? - Answers Gravity profile
What are the key indicators in a gravity profile? - Answers Time to reach final gravity and final gravity
What does OG-FG indicate in brewing? - Answers Amount of sugar fermented
What does it mean when a wort is fully attenuated? - Answers Yeast has used up all fermentable sugar
Fully Attenuated - Answers Yeast uses all fermentable sugar, end of fermentation
, Plato Scale - Answers Converts specific gravity to weight percent of sucrose in wort
What is specific gravity (SG) in the context of density measurement? - Answers SG = Weight of a volume
of sample/weight of equal volume of water at 20 degrees
How is Plato scale used in density measurement? - Answers Plato scale is used to convert SG to weight
percent of sucrose (e.g., 12 degrees Plato = 12% sugar by weight in the solution)
How is ABV (Alcohol by Volume) calculated using gravity measurements? - Answers ABV = (Original
Gravity - Final Gravity) x 0.13
What is fermentability in the context of density measurement? - Answers Fermentability = Degrees
fermented/Plato Gravity x 100
What is the purpose of maximum cooling in the brewing process? - Answers Max cooling is used to stop
fermentation early, commonly seen in cask beer or traditional lagering
What test can be done to problem solve fermentation stopping early - Answers Forced fermentation test
(AL)
What steps can be taken if fermentation stops early? - Answers Perform AL testing. If gravity does not
change, it may be a brewhouse issue. If gravity drops, it is likely a fermentation issue caused by wort
oxygenation, pitching rate, temperature control issues, wrong yeast strain, selection of a more
flocculant mutant, or a malt problem.
What are some key indicators of a successful fermentation? - Answers Time to reach gravity and VDK
spec, correct degree of attenuation, expected yeast crop size and consistency, yeast crop viability,
expected ABV, true to type flavor
VDKs - Answers Beer flavor compounds produced by yeast during fermentation
What is diacetyl? - Answers A flavor compound formed in the early fermentation stages. Undesirable
flavour in lagers
How is diacetyl managed during fermentation? - Answers It is mopped up by yeast after final
attenuation, so having enough yeast at the end of fermentation is crucial.
Cycle Time - Answers Duration for fermentation to finish, excluding filling, emptying and cleaning
What is Warm VDK Stand? - Answers Rapid process where beer is kept at fermentation temperature
after the log phase so that yeast is active enough to remove VDK. Temperature only goes down after
VDK concentration has decreased below a threshold.
Why is Warm VDK Stand important in brewing? - Answers Fermentation is not complete until VDKs have
gone below a certain threshold, making it crucial to keep the beer at a warm temperature to ensure the
yeast is active enough to remove VDK
Fermentation - Answers Yeast growth on wort, converting extract into alcohol and CO2
Industrial Fermentation - Answers Controlled conversion of wort into beer by yeast and possibly other
microorganisms
Alcohol (Ethanol) - Answers Product of fermentation process
How is fermentation monitored - Answers Decrease in wort gravity by a hydrometer or densitometer
How does yeast adjust during the lag phase - Answers Yeast adjusts its physiology in response to being
moved from starvation conditions to growth conditions.
What happens to yeast during the lag phase? - Answers Yeast takes up oxygen, breaks down glycogen,
and synthesizes essential membrane lipids, sterols, and unsaturated fatty acids.
What is the outcome of the lag phase in fermentation? - Answers The yeast is prepared to grow and
convert extract into alcohol and CO2 during fermentation.
What characterizes the Log Phase in brewing? - Answers Wort gravity decreases at the maximum rate,
controlled by various factors.
What controls the rate of wort gravity decrease in the Log Phase? - Answers Initially, the rate is
controlled by pitching rate and wort oxygen levels, then by temperature.
What reaches their maximum levels during the Log Phase in brewing? - Answers Rates of CO2 formation,
alcohol, and yeast concentration.
Deceleration Phase - Answers Yeast stops multiplying, wort gravity decrease slows. Occurs due to
running out of essential nutrient, or alcohol too concentrated.
What happens during the stationary phase? - Answers Cells return to starvation state, constant wort
gravity.
What is the relationship between cell growth and cell death in the stationary phase? - Answers Rate of
cell growth equals the rate of cell death.
What do brewers monitor to track the progress of fermentation? - Answers Gravity profile
What are the key indicators in a gravity profile? - Answers Time to reach final gravity and final gravity
What does OG-FG indicate in brewing? - Answers Amount of sugar fermented
What does it mean when a wort is fully attenuated? - Answers Yeast has used up all fermentable sugar
Fully Attenuated - Answers Yeast uses all fermentable sugar, end of fermentation
, Plato Scale - Answers Converts specific gravity to weight percent of sucrose in wort
What is specific gravity (SG) in the context of density measurement? - Answers SG = Weight of a volume
of sample/weight of equal volume of water at 20 degrees
How is Plato scale used in density measurement? - Answers Plato scale is used to convert SG to weight
percent of sucrose (e.g., 12 degrees Plato = 12% sugar by weight in the solution)
How is ABV (Alcohol by Volume) calculated using gravity measurements? - Answers ABV = (Original
Gravity - Final Gravity) x 0.13
What is fermentability in the context of density measurement? - Answers Fermentability = Degrees
fermented/Plato Gravity x 100
What is the purpose of maximum cooling in the brewing process? - Answers Max cooling is used to stop
fermentation early, commonly seen in cask beer or traditional lagering
What test can be done to problem solve fermentation stopping early - Answers Forced fermentation test
(AL)
What steps can be taken if fermentation stops early? - Answers Perform AL testing. If gravity does not
change, it may be a brewhouse issue. If gravity drops, it is likely a fermentation issue caused by wort
oxygenation, pitching rate, temperature control issues, wrong yeast strain, selection of a more
flocculant mutant, or a malt problem.
What are some key indicators of a successful fermentation? - Answers Time to reach gravity and VDK
spec, correct degree of attenuation, expected yeast crop size and consistency, yeast crop viability,
expected ABV, true to type flavor
VDKs - Answers Beer flavor compounds produced by yeast during fermentation
What is diacetyl? - Answers A flavor compound formed in the early fermentation stages. Undesirable
flavour in lagers
How is diacetyl managed during fermentation? - Answers It is mopped up by yeast after final
attenuation, so having enough yeast at the end of fermentation is crucial.
Cycle Time - Answers Duration for fermentation to finish, excluding filling, emptying and cleaning
What is Warm VDK Stand? - Answers Rapid process where beer is kept at fermentation temperature
after the log phase so that yeast is active enough to remove VDK. Temperature only goes down after
VDK concentration has decreased below a threshold.
Why is Warm VDK Stand important in brewing? - Answers Fermentation is not complete until VDKs have
gone below a certain threshold, making it crucial to keep the beer at a warm temperature to ensure the
yeast is active enough to remove VDK
