How to Return Exams: Preferred method: Scan, save as a pdf and email to exam@abgbrew.com Please create a separate file for brewing and engineering exams (we sent the engineering portion to Dan to grade separately). One file only for each section please and label it with your name. (We ve previously been sent a completed exam consisting of 20 individual pdf s and there s a very real possibility that one will get lost) Mail to: (keep a copy) American Brewers Guild 1001 Maple St Salisbury VT 05769 Please follow these guidelines when answering the exam questions: (1) You may use your books and notes to answer the following questions. (2) Do not consult with others; work by yourself. No discussing the answers on the forum. (3) Show all of your work; credit is also given for your approach. (4) Put a box around your final answers in which calculations are required. (5) Try to write neatly; Spread your work out so that it can read and understood. (6) Start each problem on a new piece of paper unless the previous problem used less than 1/2 a page. (7) Answer the descriptive portions of the exam concisely. (8) The instructors will not provide you with assistance in completing this exam. Brewing 1) According to Morten Meilgard a) What are the three primary flavor components of an American pale lager? b) What are the primary flavor components of specialty beers? 8 points 2) What are three essential differences between a sensory analyst and an organaleptic taster? 3 points 1
3) Modification has a proximal to distal pattern in malting that leaves a steely tip. Explain this phenomenon, mentioning enzymes and hormones involved by name. 8 points 4) What are the three phases of grain drying during pale malt kilning, and write a brief description of each? 5) What are -glucans, where are they found, and why are they important in brewing? 5 points 6) a) Name the two reactants involve in the Maillard reactions. b) What two strategies are employed by maltsters to increase the concentration of the Maillard products. c) Briefly, why would the maltster be interested in controlling the Maillard reactions? 7) Name the two components of barley starch on the diagram attached, and draw how -amylase, -amylase and limit dextrinase would act upon them. Also label all of the reducing and non-reducing ends of each molecule. + 1 bonus available 8) You receive a malt shipment showing the following analysis: Moisture 4.0% Soluble Protein 3.05 Total Protein 11.2 Extract, finely ground, as is 82.0 Extract, coarse, as is 78.0 Calculate the following: S/T ratio Extract, finely ground, dry basis Extract, coarse, dry basis Fine-Coarse difference (dry basis) 2
Would you consider this malt to be over, under, or well modified? List a milling and mashing regime that you feel would adequately convert this malt. 9) Explain the difference between total nitrogen, soluble nitrogen and free amino nitrogen (FAN). 10) Given the following water analysis, calculate the residual alkalinity of the water. Would this water have an alkalizing or acidifying affect on the mash ph? Ion Molecular Weight ppm Ca 2+ 40 250 Mg 2+ 24 25 - HC0 3 61 60 2- S0 4 96 120 Na + 23 10 11) Examine the brewhouse shown on the attached diagram. Describe how you would convey malt from the silo through the mill, into the grist case and finally to the mash tun? Draw your conveying system on the diagram. Explain your choices. 12) (i) Relate fineness of milling to extract yield and ease of wort recovery. 2 points (ii) How do these factors change in: a) Infusion mash tun b) Lauter tun c) Mash filter 13) During a normal run-off in an infusion mash, the mash bed tends to compact. Why, and how is this controlled? 5 points 3
14) Answer the following true/false questions about mashing enzymes: a) -glucanase is primarily responsible for wort fermentability. b) -amylase can cleave the -1 6 bonds of amylopectin. c) -amylase is required to degrade amylose to maltose. d) -amylase can break the -1 3 bonds of the pentosans and b-glucans. e) -amylase can degrade un-gelatinized starches. 5 points 15) Compare the following infusion mashes #1 #2 L:G Ratio 2:1 4:1 Temperature 149 158 Which mash would have a higher fermentability? Which would you expect to have a higher extract yield? Explain your reasoning. 4 points 16) Given the information on the recipe sheet attached, calculate the other values. 11 points 17) Hops contain and acids, explain how these may be responsible for bitterness 4 points 18) What is hop utilization and what factors increase it? 19) State at least four benefits of a vigorous boil. Give a one sentence description for each benefit. 8 points 20) Describe the action of a whirlpool with a diagram. Why does material not simply settle on the outside perimeter of the tank due to centrifugal force 4 points 4
ENGINEERING EXAM #1 Instructions and hints: Please start a new page for your engineering exam since your engineering exam is graded by somebody else. Put your name clearly on each page of your work in case the wind blows all the pages around. Save a copy of your exam in case my dog eats your pages. Each correct question is worth 10 points. An incorrect answer is worth zero points. However, if you don t show any work, you will not receive any points. It is possible to write neatly, show your work and have the exam answers fit on one or two pages. o If you have absolutely no idea how to solve the question, and wish to receive partial credit, show some reasonable detail about how you went about investigating an answer. It should be easy to get half credit on any question if you at least try something. Be careful on unit conversions. Many students get something backwards. 1. A 50 bbl fermenter takes 30 minutes to fill, what is the flow rate in: a. Gallons per minute b. Hecto Liters per hour c. If the wort is SG 1.050, what is the mass flow rate (kg/s)? d. If the maximum allowable flow rate of wort is 7 ft/sec, what minimum size brewer hose would you select? 2. A brew kettle has a nice even 1/32 layer of calcium oxalate (beerstone) on the inside. The stainless steel is 3/16 (K=16 W-m/m 2 K). a. Explain what would happen if the beer stone was removed and what quality issues this may involve with the production of your beer? 5
b. What is the heat flow in kilowatts per square meter for the two layer system that includes the kettle s stainless steel and the beerstone (Kstone = 0.85 W-m/m 2 K) assuming the driving force as you come to a boil is a delta T of 50 Kelvin. c. How many kw/m 2 would you expect with no beer stone? d. How can we remove beer stone? 3. In the brewery, we normally mash into a preheated vessel at 67 C with 350 kg of malt (Cp = 1.8 kj/kg K) of initial temperature 10 C and 1050 kg of water (Cp = 4.182 kj/kg K) at 75 C and this gives us an initial mash temperature of 67 C. Suppose you forgot to preheat the mash mixer (680 kg stainless steel, Cp = 0.46 kj/kg K) one cold November morning when it was 10 C in the brewhouse. Assume no heat losses to the atmosphere, but all the other laws of thermodynamics apply to you. a. Would the initial mash temperature be higher or lower than you intended? b. After writing the controlling equation, what would the initial mash temperature be? c. How much additional water at 75 C would you need to add in order to bring the entire mash and the vessel up to 67 C? d. What is the Liquor:Grist ratio after you make the addition in Q 3.C.? 4. Why does stirring a pot as it heats up cause a boil quicker than unstirred? Draw a picture or use equations to help explain your answer. 5. A small 1,000 bbl per year capacity brewpub has a boiler designed to run a 15 bbl kettle, heat other hot water, and steam cleaning with the keg cleaner. Explain how we can use the enthalpy change (not latent heat) from the phase change in a boiler loop to replace the recently broken commercial water heater used in the brewpub kitchen. Name at least one reason why this is not a good idea. (10 points for each question) 6
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Silo Grist Case 16ft 1.3ft 2.5ft Mash Tun 12.2ft Mill 4.3 ft 8
Exam # 1 Brew DESIRED CHARACTERISTICS COLD WORT VOLUME 20 BBL gal GRAVITY 19.0 Plato S.G. LIQUOR:GRIST RATIO 3:1 TARGET BITTERNESS 65 IBU SYSTEM CONSTANTS BREWHOUSE YIELD 87% MASH TEMPERATURE (ºF / ºC) 158 ºF MALT TEMPERATURE (ºF / ºC) 38 ºF MASHING REQUIREMENTS LIQUOR VOLUME bbl gal LIQUOR TEMPERATURE (ºF / ºC) F WORT SPECIAL MALT TYPE WEIGHT HWE % OF COLOR (LB) AS-IS EXTRACT (L) Pale Malt 79% 80% Crystal Malt 75% 5% Carapils 75% 10% Munich 78% 4% Roasted Barley 72% 1% TOTALS 100% HOP VARIETY % ALPHA % OF % WEIGHT WEIGHT TOTAL BU'S UTILIZATION (grams) (lbs) Columbus 14 96 30 Cascade 5 4 2.5 Malt Colors L Pale Malt 2 Crystal Malt 60 Carapils 22 Munich 8 Roasted Barley 500 9