Master Brewer Certification Brewer Raw Materials & Ingredients 3 — Questions and Answers
Question 1: Which hop variety was the first American-bred cultivar released by USDA and became foundational to the Pacific Northwest hop industry?
- Cascade
- Centennial
- Cluster (Correct answer)
- Columbus
Correct answer: Cluster
Cluster is one of the oldest American hop varieties, a USDA-developed cultivar that dominated US hop production for decades before the craft beer movement popularized varieties like Cascade.
Question 2: What does the term 'modification' refer to when describing malting barley quality?
- The degree to which the starchy endosperm cell walls have been broken down by enzymes during malting (Correct answer)
- The color change caused by Maillard reactions during kilning
- The ratio of alpha to beta amylase activity in finished malt
- Moisture content reduction achieved during withering
Correct answer: The degree to which the starchy endosperm cell walls have been broken down by enzymes during malting
Modification describes the enzymatic breakdown of beta-glucan cell walls and protein matrix in the endosperm during germination, making starch accessible for mashing.
Question 3: A brewer wants to brew a Hefeweizen with authentic banana ester (isoamyl acetate) character. Which raw material consideration most directly supports this goal?
- Using wheat malt with high FAN to provide sufficient amino acids for ester synthesis (Correct answer)
- Adding banana extract post-fermentation to supplement yeast esters
- Using low-nitrogen barley malt to suppress ester formation
- Increasing sulfate in water to accentuate the fruity character
Correct answer: Using wheat malt with high FAN to provide sufficient amino acids for ester synthesis
Isoamyl acetate is synthesized from isoamyl alcohol and acetyl-CoA during fermentation; adequate FAN from wheat malt ensures yeast have the amino acid precursors for ester production at low fermentation temperatures.
Question 4: Which mineral addition would a brewer use to replicate soft, round Dublin-style water suitable for dry Irish stout?
- Gypsum (CaSO₄)
- Calcium chloride (CaCl₂)
- Sodium bicarbonate (NaHCO₃) (Correct answer)
- Magnesium sulfate (MgSO₄)
Correct answer: Sodium bicarbonate (NaHCO₃)
Dublin water is naturally high in bicarbonate, which buffers mash pH upward, suits dark roasted malts, and imparts the soft, round palate associated with dry stouts.
Question 5: Diastatic power (DP) measures a malt's ability to convert starches. What is the minimum DP (in degrees Lintner) generally recommended for a mash that contains 30% unmalted adjuncts?
- 25°L
- 50°L
- 100°L (Correct answer)
- 150°L
Correct answer: 100°L
A DP of at least 100°L is generally considered the minimum threshold for mashes with significant adjunct loads to ensure complete starch conversion within a normal mash time.
Question 6: Which component of hops is primarily responsible for the 'cheesy' or 'goaty' off-aroma that develops when hops are stored improperly at warm temperatures?
- Alpha acids oxidizing to iso-alpha acids
- Myrcene volatilizing from hop oil
- Isovaleric acid forming from the breakdown of alpha acids (Correct answer)
- Geraniol converting to citronellol
Correct answer: Isovaleric acid forming from the breakdown of alpha acids
Isovaleric acid is produced when alpha acids (particularly humulone) oxidize and degrade under warm storage conditions, giving hops and beer a rancid cheese or sweaty aroma.
Question 7: Rice is used as a brewing adjunct in certain lager styles. Compared to corn grits, which statement best describes rice's contribution to beer flavor?
- Rice contributes a pronounced grainy sweetness similar to corn
- Rice contributes an even more neutral flavor profile than corn (Correct answer)
- Rice adds significant color due to its natural pigments
- Rice contributes more body than corn due to its protein content
Correct answer: Rice contributes an even more neutral flavor profile than corn
Rice is considered a more neutral adjunct than corn, contributing fermentable sugars with minimal flavor impact, which is why premium light lagers like Budweiser use rice for a very clean profile.
Master Brewer Certification Brewer Raw Materials & Ingredients 3
Which hop variety was the first American-bred cultivar released by USDA and became foundational to the Pacific Northwest hop industry?