CFPS Beer Service and Cellar Management 2 — Questions and Answers
Question 1: What CO2 pressure range is typically used to maintain a properly carbonated keg of American lager at 38°F?
- 10–14 PSI (Correct answer)
- 25–30 PSI
- 2–5 PSI
- 35–40 PSI
Correct answer: 10–14 PSI
At 38°F, most American lagers (2.5–2.7 volumes CO2) require 10–14 PSI of serving pressure to maintain carbonation without over- or under-carbonating.
Question 2: Beer lines that are too long or have too little resistance will cause:
- Foamy, over-carbonated pours (Correct answer)
- Flat, under-carbonated pours
- Oxidized off-flavors
- Skunky light-struck aromas
Correct answer: Foamy, over-carbonated pours
If there is insufficient line resistance (lines too short or large diameter), beer flows too quickly and pressure drops cause CO2 to come out of solution, resulting in excessive foaming.
Question 3: How often should draft beer lines be cleaned according to the Brewers Association guidelines?
- At least every two weeks (Correct answer)
- Once per year
- Only when a new keg is tapped
- Daily with hot water rinse
Correct answer: At least every two weeks
The Brewers Association recommends cleaning draft lines with caustic or enzyme cleaner at least every two weeks to prevent biofilm, yeast, and bacteria buildup that can cause off-flavors.
Question 4: What is the purpose of a mixed gas (beer gas) blend such as 70% N2 / 30% CO2?
- To serve stouts and nitro beers at low carbonation with a creamy, cascading head (Correct answer)
- To increase alcohol content during service
- To purge oxygen from empty kegs before filling
- To force-carbonate beer faster
Correct answer: To serve stouts and nitro beers at low carbonation with a creamy, cascading head
Nitrogen is nearly insoluble in beer and provides serving pressure without over-carbonating, allowing stouts and nitro beers to be served at the low carbonation levels needed for their creamy, cascading pour.
Question 5: A 'bright tank' in a brewery is used for:
- Final conditioning, carbonation, and storage before packaging or service (Correct answer)
- Initial mash and wort separation
- Fermenting beer with active yeast
- Storing grain before milling
Correct answer: Final conditioning, carbonation, and storage before packaging or service
A bright tank (also called a serving tank or brite tank) receives filtered beer from the fermenter for final carbonation adjustment, clarification, and holding before packaging.
Question 6: When tapping a new keg, what is the first step a cellarman should take?
- Allow the keg to rest at cellar temperature for at least 24 hours before tapping (Correct answer)
- Connect the gas line immediately upon delivery
- Tap the keg while warm to purge any contamination
- Shake the keg to mix any settled yeast
Correct answer: Allow the keg to rest at cellar temperature for at least 24 hours before tapping
Kegs should be allowed to rest undisturbed at serving temperature for at least 24 hours after transport to allow CO2 to re-dissolve and any agitation-induced foam to settle.
CFPS Beer Service and Cellar Management 2
What CO2 pressure range is typically used to maintain a properly carbonated keg of American lager at 38°F?