Master Brewer Certification Advanced Cooking Techniques & Methods 2 — Questions and Answers
Question 1: When producing a wort with a high adjunct ratio (>40% corn grits), which mashing technique is most critical to ensure full starch conversion?
- Single infusion at 152°F
- Cereal mash with subsequent blending into the main mash (Correct answer)
- Decoction mash with triple boiling
- Cold steeping overnight at 35°F
Correct answer: Cereal mash with subsequent blending into the main mash
Corn grits require a cereal mash step to gelatinize starches before blending with the main mash for enzymatic conversion.
Question 2: A brewer notices persistent haze in a filtered lager despite extended cold conditioning. Which advanced technique best addresses protein-polyphenol chill haze?
- Increase mash temperature to 162°F
- Add silica gel or bentonite during conditioning (Correct answer)
- Extend boil time to 120 minutes
- Reduce hop additions during whirlpool
Correct answer: Add silica gel or bentonite during conditioning
Silica gel adsorbs haze-active proteins while bentonite removes polyphenols, both directly targeting the protein-polyphenol complexes causing chill haze.
Question 3: During the Maillard reaction in wort kettle caramelization, which precursor pair is primarily responsible for melanoidin formation?
- Amino acids and reducing sugars (Correct answer)
- Fatty acids and hop alpha acids
- Calcium ions and phosphates
- Sulfur compounds and polyphenols
Correct answer: Amino acids and reducing sugars
Melanoidins form when amino acids react with reducing sugars (like glucose and maltose) via the Maillard reaction during wort boiling.
Question 4: Which mash temperature range maximizes the activity of beta-amylase for a highly fermentable, dry wort profile?
- 140–145°F (60–63°C)
- 148–154°F (64–68°C) (Correct answer)
- 158–162°F (70–72°C)
- 165–170°F (74–77°C)
Correct answer: 148–154°F (64–68°C)
Beta-amylase is most active between 148–154°F, producing the maltose-rich, highly fermentable wort desired for dry beer styles.
Question 5: A master brewer wants to increase wort viscosity for a full-bodied oatmeal stout. Which mashing approach achieves this?
- Lower mash pH to 5.0
- Increase alpha-amylase rest temperature to 162°F to favor dextrins (Correct answer)
- Add exogenous amyloglucosidase at knockout
- Extend lauter time with a thick mash
Correct answer: Increase alpha-amylase rest temperature to 162°F to favor dextrins
Mashing at higher temperatures (around 158–162°F) favors alpha-amylase and produces more unfermentable dextrins, contributing body and viscosity.
Question 6: In the context of step mashing, what is the primary purpose of a protein rest at 122°F (50°C)?
- To gelatinize adjunct starches before saccharification
- To activate proteolytic enzymes that break down large proteins, improving head retention and filterability (Correct answer)
- To denature lipase and prevent staling
- To solubilize hop acids prior to the boil
Correct answer: To activate proteolytic enzymes that break down large proteins, improving head retention and filterability
A protein rest at 122°F activates proteases that cleave large proteins into smaller peptides and free amino nitrogen, improving foam and clarity.
Question 7: When using a recirculating infusion mash system (RIMS), a brewer must primarily guard against which thermal risk?
- Over-acidification from lactic bacteria during recirculation
- Scorching of enzymes at the heating element if flow rate is too low (Correct answer)
- Excessive CO2 off-gassing destabilizing the grain bed
- Hop oil volatilization from elevated mash temperatures
Correct answer: Scorching of enzymes at the heating element if flow rate is too low
In a RIMS system, insufficient flow past the heating element can create localized hot spots that denature mash enzymes or scorch wort.
Master Brewer Certification Advanced Cooking Techniques & Methods 2
When producing a wort with a high adjunct ratio (>40% corn grits), which mashing technique is most critical to ensure full starch conversion?