FST102A Question Collective PDF

1. Diacetyl produces a butterscotch flavor 2. There are yeasts that CAN metabolize maltotriose 3. Ethanol is the NOT only type of alcohol produced during fermentation 4. Volatile compounds include: a. higher alcohols b. sulfur compounds c. organic acids d. VDKs 5. During...

1. Diacetyl produces a butterscotch flavor 2. There are yeasts that CAN metabolize maltotriose 3. Ethanol is the NOT only type of alcohol produced during fermentation 4. Volatile compounds include: a. higher alcohols b. sulfur compounds c. organic acids d. VDKs 5. During fermentation, one molecule of glucose will produce two molecules of ethanol and two molecules of carbon dioxide. 6. It is possible to produce an ale beer with a lager yeast 7. There are many ways to use dried yeasts 8. Which yeast is primarily responsible for the production of alcohol during beer fermentation? Saccharomyces 9. Generally, brewers use different species of Saccharomyces yeasts to brew ales and lagers 10. Proline is the least preferred amino acid by yeast 11. Yeast does not metabolize maltose before glucose (opposite) 12. In order to maintain a pure culture of yeast for repitching, some tips include: a. regular microbiological assessment b. Storing yeast at around 4°C c. acid washing between pitches d. water sedimentation 13. Ca mineral aids in flocculation (Zinc can too) 14. You would expect genetic mutation in yeast after 100 repitches 15. Diacetyl flavor threshold is around 0.1 mg/L to 1.0 mg/L 16. A Specific Gravity of 1.072 would be considered a high gravity wort 17. In fermentation, Saccharomyces yeast can produce alcohol contents greater than 8% 18. Yeast will produce more ethanol if oxygen is pumped into the fermenter during fermentation 19. Ferulic acid is decarboxylated to 4-VG, producing phenolic off-flavor (POF) 20. Most yeast do not reproduce via sexual reproducing with other yeast cells 21. During fermentation, ethanol is not produced continuously until the brewer stops fermentation 22. Which of these increase during fermentation: a. yeast cells b. carbon dioxide c. Alcohol d. Aroma 23. Ethylhexanoate: a. smells like pineapple b. is an ester 24. Yeast will not metabolize glucose and maltose at the same time 25. Yeast does not produce more alcohol during respiration than fermentation 26. LTP becomes more foam positive during boiling 27. Excessive filtration and clarification of beer will not improve foaming properties 28. Iso-alpha acids have a positive influence on foam 29. Free fatty acids do not improve foam stability 30. Serpin also known as protein Z, is a foam stabilizer but it is also a Serine protease inhibitor 31. Proteins that are better at forming foam will keep out proteins that are more foam-stabilizing 32. Surface tension is influenced by the amount of carbon dioxide 33. Proteinase A improves foam stability and is produced by yeast 34. When plotting the relationship between protein content and foam stability, you would use first or second order rate laws 35. When plotting the relationship between protein content and foam stability the plot would take on a positive exponential, thus the relationship is only partially linear 36. A typical bubble radius could be 0.5 mm 37. An albumin from egg improves beer foam stability, but is rarely used for allergen reasons. 38. Nitrogen gas will decrease the bubble size of beer foam 39. For a bubble to foam, it needs a nucleation point 40. Beer temperature influences beer foam 41. Generally there is more than enough protein content to create foam bubbles 42. Nucleation sites (such as scratches on glass) are responsible for beading, which replenishes the foam in beer 43. Higher hydrogen ion concentrations are associated with increased sourness in beers. 44. carbon dioxide is directly correlated to a tingling mouthfeel 45. Bitterness is due to iso-alpha acids. 46. Sourness is related to pH 47. You smell beer two ways. You smell it directly and through the retronasal effect: Through the back of the throat 48. To address flavor instability, minimize the oxygen level in the finished package 49. Adding hops at different times during the boil changes the hop character of the beer. 50. In an experiment performed by Dr. Bamforth outlined in the text, he took two yellow tinted beers and darkened one to look more like an ale. People then scored the two beers as having different flavors. What does their reaction say about quality? a. People make judgments on quality based on visual cues before even trying the beer 51. When two glasses of the same beer are compared, the glass with a stable foam is generally considered a superior product. 52. Yeast cell viability is measured using methylene blue 53. The most abundant sugar in wort is Maltose 54. VDKs can be controlled by fermentation time and temperature 55. Yeast are able to metabolize sugars larger than a disaccharide 56. The lag phase is at the start of fermentation 57. Adding extra maltotetrose during the stationary phase of fermentation will NOT increase the final content 58. Lipids help build yeast cells 59. At the end of fermentation, yeast will flocculate 60. Yeast are more likely related to animals than bacteria 61. Organic acids released by yeast helps lower the pH during fermentation 62. Dosing with carbon dioxide or nitrogen at packaging will NOT decrease foam properties 63. Nitrogen gas has a positive influence on a. Bubble size b. Foam color c. Foam stability d. Mouthfeel 64. Nitrogen gas will decrease the foam bubble size 65. Miller Coors has a history of using tetrahops to improve foam stability 66. Which of the following have positive impacts on foam formation and retention in beer? a. Iso-alpha acids b. Manganese c. Peptides d. Propylene glycol alginate 67. The CO2 range of finished beer is typically 1.0 - 5.0 mg/ml 68. There is more than one foam positive protein that comes from malt 69. High ethanol content does NOT increase foam stability 70. Generally, wines can vary by vintage whereas beers do not 71. You should swallow beer because of the retronasal effect, not because the bitter taste buds are at the back of the tongue. 72. People tend to make a decision about the quality of a beer based on the package and label. 73. The flavor threshold refers to the lowest concentration at which a substance becomes detectable 74. Sweetness in beers is not influenced by sugar content 75. Most of the flavor of beer is NOT detected through the tongue, maybe the nose 76. A component with a lower flavor threshold will make a bigger contribution to the character of the beer. 77. A can is a package that provides 100% resistance to MBT formation 78. Adding rice during mashing will increase the amount of sugars to assist in fermentation 79. LTPs and Protein Z are water soluble/foam positive proteins making them Albumins 80. Hordeins contain a lot of hydrophobic amino acids which aids foam flavor in 81. Bitter acids promote foam and maintains bubbles 82. Grease and Detergent kill foam because of their hydrophobic/hydrophilic interactions 83. Surface tension is influenced by amount of CO2 84. 25 bitterness receptors in the human genome 85. Bitter acids are iso-alpha-acids and promote foam and bubble stability 86. Ales are infusion mashing, Lagers are decoction mashing 87. Yeast hydrophobicity influences flocculation 88. Esters are only produced when the alcohol content is greater than 10%. a. false 89. Saccharomyces cerevisiae var. diastaticus will metabolize dextrins 90. Yeast produces more alcohol during respiration than fermentation a. False other way around 91. The only way to use dried yeasts is to rehydrate prior to pitching a. False 92. Yeast will metabolize glucose and maltose at the same time a. False 93. Yeast will metabolize maltose before glucose a. False 94. A wort with an original gravity = 20 oPlato will speed up fermentation compared to an original gravity = 1.040 specific gravity 10 Plato. a. False 95. No yeast are able to metabolize sugars larger than a disaccharide a. False 96. A key mineral for enhancing yeast metabolism is Zn+ 97. Fermentation temperature will influence the amount of esters synthesized by yeast 98. The radius of the nucleation site influences bubble size 99. Which foam positive proteins come from yeast vs malt? a. Yeast: Proteinase A b. Malt: Hordeins, Protein Z, LTP 100. All proteins are foam positive a. False 101. Tetra iso-alpha acids can negatively effect the visual appearance of foam 102. LTP and protein Z are water soluble proteins making them Albumins 103. You smell beer two ways. You smell it directly and through the retronasal effect. What is the retronasal effect? a. Through the back of the throat 104. In addition to proteins, which substance helps maintain bubbles and promote foam? a. Bitter acids 105. What package provides 100% resistance to MBT formation? a. A can 106. Which of the following were mentioned in lecture to be direct contributors to the flavor of beer (select all that apply)? a. Water b. Hops c. Malt d. Adjuncts e. Yeast 107. What are the four main tastes mentioned in lecture? a. Salty b. Bitter c. Sweet d. Sour 108. Contamination with fusarium results in what unpleasant consequence? a. Gushing 109. When you expose beer to light you get MBT which has the aroma of what? a. Skunk 110. Excessive oxygen is bad in beer 111. Iso-alpha acids will bind to peptides in the bubble wall then cross link via a metal to form the foam 112. The cleanliness of the glass impacts the foam properties 113. Beer quality is defined as a consistent product that the consumer wants and will buy again 114. Which of the following is not a mouthfeel?  a. Salty 115. The saltiness in beer is due to sodium and potassium 116. A good quality beer is determined by the consumer and not by tasting professionals 117. Disproportionation is when gas goes from a small bubble to a big bubble 118. Dextrins are not highly fermentable by the majority of yeasts 119. Methods to investigate foam quality include rate of foam formation, foam stability and lacing 120. There isn’t only one foam positive protein that comes from malt 121. When it comes to quality, breweries must be mindful that what the customer wants is what really matters 122. Nitrogen is directly correlated to a smooth mouthfeel