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| Question | Answer |
| What kind of a hazard does malt dust represent? | -Explosion Hazards -Allergic Reactions -Lung Disease - long term -Lung damage - Immediate -Brewery Cleanliness and sanitation -product Integrity(contaminate wort) |
| What kinds of gases may be used in a brewery? | -Oxygen -Carbon Dioxide -Nitrogen -Industrial Gases -Laboratory Gases |
| -What measures can be taken to reduce pressure hazards in brewing thanks? | -Use safe operating procedures -Use vessel safety Devices -Install pressure sensing warning devices and interlocks -Cleaning and maintenance of vessel safety devices |
| What information is on a MSDS information sheet? | It is intended to provide workers and emergency personnel with procedures for handling or working with that substance in a safe manner, and includes information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill-handling procedures. MSDS formats can vary from source to source within a country depending on national requirements. |
| Why is water such an effective solvent? | water is polar, and it also dissolves many substances. |
| Why is calcium important in brewing water? | -Protects enzymes from thermal degradation, and extends activity. -Improves trub formation during wort boil. -Encourages precipitation of calcium oxalate (beer stone) in tanks instead of package, if allowed in package may cause gushing -Decreases pH during mashing and wort boil. -100 ppm calcium addition decreases wort pH 0.4 pH units. |
| What is temporary hardness? | Hardness that can be removed by boiling. -contains calcium and magnesium bicarbonates. |
| What is permanent hardness? | -Hardness that cant be removed in the boil. -Contains calcium sulfate and magnesium sulfate. |
| What are the most commonly used brewing salts? | -Calcium -magnesium |
| Define residual alkalinity? | a measure of the alkalinity left after the acidifying reaction between the malt's phosphates and the water's calcium and magnesium has been taken into account. |
| List factors that contribute to a successful brewery startup? | -Organized Market Research -professional plant/equipment design/planning -sound/realistic business plan: product mix, product quality. -adequate funding -timing -good luck |
| What kinds of analyses must be done when planning a new brewery? | -Market area analysis -Project site and area analysis -competition -demand |
| What is demand analysis? | Demand analysis is a study that uses the data collected from sales of a specific good or service to determine if the product or service will be successful on the market or not. These studies can also be used to help find ways to increase the sales performance of the good or service in the future. |
| How do you decide what level of risk is acceptable in business planning? | By gathering all your analysis, and determining whether or not one can go bold, or play it safe. |
| Describe alpha-acid utilization during the beer production? | Alpha-acids are converted by isomerization process during the wort boiling stage. thus helping with bittering and aromas in beers, helps with biological stability, colloidal stability, and foam stability. |
| describe the hop cone. | the hop cone consists of a spindle, cone leaves and lupulin glands. |
| Where are the hop resins located? | Hop resins are located in the lupulin glands. |
| List 4 Countries importing/exporting hops. | U.S.A, Germany, The Czech Republic, and Poland. |
| List 2 American aroma hops. | Cascade, Mt. Hood. |
| List 2 American Bittering Hops. | Cluster, and Chinook. |
| List 2 German aroma hops. | Hersbruck, Perle. |
| List 2 German bittering hops. | magnum, merkur |
| Explain the term isomerization of alpha-acids. | Isomerization of alpha-acids means that the alpha acids have been boiled and converted to iso-alpha-acids. |
| What is the reason for sun-struck or skunky flavor? | ultra-violet rays cause a deterioration in the aroma of the beer. It reacts with iso-alpha-acids and produces 3-methyl-2-butene-1-thiol. |
| What is the advantage of using pre-isomerized hop products? | -Higher yields of bittering -easy to store and handle -high stability. |
| Explain the difference between type 45 and type 90 pellets. | Type 45 have 45% of the original hop cone in it, where type 90 has 90% of the original cone. |
| Which 3 solvents are used to create hop extract from raw hops? | CO2, Ethanol, and Hexane. |
| What is a catalyst? | Catalyst is a substance that increases the rate of chemical reaction without itself undergoing any permanent chemical change. |
| What Large biochemical family do enzymes belong to? | Proteins |
| What is the common ending for all enzyme names? | ase |
| What does malt modification mean? | malt has been processed and that both starches and proteins become more accessible. |
| what practical way can a brewer determine the optimum enzymatic activity of his mash with respect to various temperatures? | Check the pH leaves at each temperature. |
| What 2 main brewing enzymes are know as starch degrading enzymes? | a-amylase, b-amylase |
| Name 2 enzymes that attack cell walls surrounding starch granules in malting barely. | B-glucanases and cytases |
| Proteins breakdown into what? | Peptides and amino acids. |
| Where is alpha amylase formed? | formed during malting at 158-160 degrees f |
| what do endo and exo stand for? | endo means from the interior of a molecule. Exo means from the end of a molecule. |
| List 4 reasons why barley malt is suitable for brewing. | -large amount of proteins and starches. -enzyme systems beneficial to brewing. -Husk protects grain and provides a filter bed, -Ably to develop different flavor combinations. |
| List the characteristics of 2-row malting barley that make it suitable for brewing. | High extract content availability low protein content low enzyme content |
| List 3 Analytical targets for the AMBA. | Plumpness protein levels germination levels |
| Why is barley husk important to brewers? | Provides protecting for the barely and provides as part of the filtration bed in lautering |
| What is the function of the aleurone layer? | releases enzymes responsible for initiating starch modification. |
| the endosperm is a living tissue. true or false | false |
| What does the acrospires become as the barley grows? | it becomes the leaf sheath |
| Why is thin barley unsuitable for brewers? | It contains less of the proteins and starches needed in the malting and brewing process. Also yields less extract. |
| What causes pre-germination? | Caused by rain or excessive humidity during ripening or in the windrow. |
| What are the effects of plant diseases? | -decreased kernel size -excessive protein -decreased extract -undesirable appearance -premature enzyme synthesis -gushing |
| What is the purpose of micro malting? | Used to determin modification potential,and modification vigor. |
| How is Germination potential measured? | measured by germination capacity tests. |
| What are the 4 "traditional" basic tastes? | Sour, salty, sweet, and bitter. |
| List 4 reasons for using sensory evaluation as a quality control tool. | -Monitor off-tastes -Maintain product consistency -validate process, ingredient changes -Helps define beer flavor profile. |
| List some reasons why sensory analysts vary from one test to the next. | To make sure the tester doesn't get fatigued, or adapted to the same beers. |
| Describe the correct procedure for tasting a beer sample | The correct procedure is to swirl and smell the beer, then drink the beer and hold it in your mouth, then swallow and wait for the aroma to come back up to the nose. |
| List 5 objectives of steeping | -clean the grain -remove floating material -increase moisture from 12% to about 44% -remove growth inhibitors. |
| What are the 2 main control parameters during steeping? | -aeration -co2 extraction |
| List 5 objectives of germination. | -controlled breakdown of cell walls and matrix proteins -production of hydrolytic enzymes -hydrolyze barley reserves -minimize loss of potential extract from growth and respiration while achieving optimal modification of carbohydrates -produce a balanced 'green malt' that will not produce excessive color during kilning |
| what are the main control parameters during germination? | Keeping temperatures between 57 and 64 degrees f, controlling humidity(44-48%) and giving proper amount of oxygen for respiratory reasons and removing co2. |
| what 3 enzymes break down starch during germination? | Starches are broken down by a-amylase, b-amylase, and limit dextrinase. |
| list 4 objectives of kilning. | -Terminate the malting process -Develop the desired color, flavor, and aroma -Stabilize the product and its enzyme package for storage -leave the malt in a friable and easily milled condition. |
| What analytical changes take place in malt during kilning? | the changes that take place are a decreased enzyme activity, color increase, pH Decrease, Soluble nitrogen decrease, extract decrease, and extractable polyphenol increase. |
| What effects do higher temps have on DMS formation? | higher temps increase S-methyl methionine(SMM) degradation and therefore increases DMS. |
| What is the most energy intensive part of the malting process? | Kilning |
| Why do we age malt? | Aging is meant to allow time for moisture equilibration in the malt. |
| What drives high extract potential and alcohol yield? | a well modified malt, with high protein and enzyme counts. |
| What determines DMS potential? | how much the moisture are in the malt, as well how modified the malt is. |
| What is FAN and what impact does it have on the brewing process? | FAN is Free amino nitrogen's, and its impacts are helps with create foam and foam stability. It helps with yeast growth, fermentation profiles and flocculation, and also helps with haze stability |
| Why is it difficult to achieve high DP and low malt protein? | because you cant have one without the other. If there is a low protein count in malt, then youll have a low DP since there wont be enough proteins to help brake down starches. |
| why is it difficult to achieve high color and high DP? | to get a high color a maltsters would have to kiln barley for longer, resulting in lost of proteins which therefore lowers DP of the barley. |
| When should specs be reevaluated? | every years harvest since barley varies from year to year. |
| list 4 reasons for using specialty malts. | A brew would use specialty malts to change the color, flavor, body of a beer, and also to improve head retention. |
| List the 3 basic classes of specialty malts. | Kilned (hi-dried)malts Roasted Malts Dry-roasted malts |
| List 4 reasons why barley malt is suitable for brewing. | -Availability -Starch and protein package -husk for the grain bed in lautering -Enzymes |
| List the characteristics of 2-row malting barley that makes it suitable for brewing. | -High extract potential -low protein content -low enzyme content |
| List 3 Analytical targets for the AMBA | Plumpness protein levels germination potential |
| why is barley husk important to brewers? | It helps protect the kernel, as well as providing a good filter bed in lautering. |
| What is the function of the aleurone layer? | To release the enzymes responsible for initiating starch modification. |
| The endosperm is living tissue. True or False? | false |
| What does the acrospires become as the barley grows? | It becomes the leaf sheath. |
| How is germination potential measured? | measured by germination capacity tests. Maltsters also conduct germinative energy tests to check that dormancy has broken. |
| why is thin barley unsuitable for brewers? | Thin barley kernels exhibit higher protein levels and also low starch levels resulting in less extract, and low fermentable sugars. |
| what causes pre-germination? | caused by rain or excessive humidity during ripening or in the windrow. |
| What are the effects of plant diseases? | can cause: -decreased kernel size -excessive proteins -decreased extract -premature enzyme synthesis |
| what is the purpose of micro malting? | helps determine modification potential, and vigor. also helps to check for mistakes on a small scale first. |
| list some reasons why sensory analysts vary from one test to the next. | taster can get fatigued. taster can also get adapted to the same beers. |
| what are the 4 "traditional" basic tastes? | sour, salty, sweet, and bitter. |
| List 4 reasons for using sensory evaluation as a quality control tool. | -Monitor off-tastes -maintain product consistency -validate process, ingredient changes -new product development |
| Describe the correct procedure for tasting a beer sample. | -First sniff the beer(with drive by or bunny sniffs). - take a sip and let it sit on your tongue, to hit all the taste buds. - swallow and wait to allow aroma to come back to the nose. |
| List 5 objectives of steeping. | -Clean the grain -remove floating material -increase moisture from 12%- about 44%(initiates germination) -remove growth inhibitors |
| what are the 2 main control parameters during steeping? | Aeration to make sure the grain can breath, and CO2 extraction so that the grain wont suffocate. |
| List 5 objectives of germination. | -Controlled breakdown of cell walls and matrix proteins -Production of a and b amylases -Minimize loss of potential extract from growth and respiration while achieving optimal modification of carbohydrates. -produce a balanced 'green malt' that will not produce excessive color during killing. |
| what are the 3 main control parameters during germination. | maintain temperature, maintain humidity, and oxygen levels for respiration and co2 removal. |
| What 3 enzymes break down starch during germination? | broken down by a and b amylase and limit dextrinase. |
| List 4 objectives of kilning. | to stop the malting process, stabilize the product and its enzyme package, develop the desired malty color, flavor, and aroma as well as leaving the malt in a friable and easily milled condition. |
| What analytical changes take place in malt during kilning? | analytical changes are decreased enzyme activities -color increase -pH decrease -extract decrease -extractable polyphenols increase -soluble nitrogen decrease |
| What effects do higher temps have on DMS formation? | higher steeping and germination temps will promote DMS formation, as well as higher kiln temps increase SMM degradation and therefore increases DMS |
| What is the most energy intensive part of the malting process? | Kilning |
| why do we age malt? | It allows the malt moisture to equalize threw the batch. |
| What drives high extract potential and alcohol yields? | a well modified malt, as well as using 2-row malt instead of 6 row. |
| what is FAN and what impact does it have on the brewing process? | FAN stand for free amino nitrogen's. Its important for foam and foam stability. Helps yeast growth, fermenting profile and flocculating. |
| which analysis is best at predicting brew house yields? | Having Malt specs. |
| What determines DMS potential | Using 2-row instead of 6 Using good kiln airflow Using higher killing temperatures |
| When should specs be reevaluated? | Every time you harvest since barley varies from year to year. |
| List 4 reasons for using specialty malts. | To give wort color, flavors, improve body, and improve head retention. |
| list the 3 basic classes of specialty malts | -Kilned malts -Roasted malts -Dry-roasted malts |
| Do kilned malts still have enzymatic activity? | yes, it is mealy with most enzymes preserved. still provides fermentable starches, sugars and amino acids. |
| List the 4 steps in the production of dry-roasted malts. | steep, germinate, kiln, roast |
| What kinds of beers is roasted barley usually used in? | darker beers such as stouts and bocks. |
| What is the purpose of malt milling? | Crack the husk to allow water in. Crush the endosperm so its exposed for speedy enzymatic degradation. Help with lautering. |
| why does the brewer want to keep the husk intact? | To act as a filtration medium. |
| List 3 types of mills. | Dry mills, wet mills and hammer mills |
| What are the principle fractions of grist? | Husk course grist fine grist flour |
| How do grist fractions differ when milling for a mash filter versus a lauter tun? | for mash filters a flour grist is needed where lauter tuns use a course grind so it doesn't get plugged up. |
| what is malt conditioning? | Malt condition involves add moisture to the husk to soften it to make it easier to remove and reduce shattering. Suppose to improve yield/ and reduce dust. |
| Define the term 'beer style'. | is a term used to differentiate and categorize beers by factors such as color, flavor, strength, ingredients, production method, recipe, history, or origin. |
| List some factors that affected the creation of most 'classic' beer styles. | -Local barley types -Different ways of making malt -local water sources -different yeast strains, temperature ranges and cross cultural influences. -introduction of hops. |
| what is the most common beer style in the world? | Lager style beers |
| Have 'traditional styles' changed over time? Give some reasons for your answer. | Traditional styles have changed over time due to knew technology, consumer taste changes, different types of malts and hops. |
| Define the term extract. | extract means to pull stuff out of something. which in brewing is the portion of the malt that goes into solution during mashing to form wort. |
| List some components of wort extract. | proteins, enzymes, starches, trub. |
| list components of modern mash tun. | CIP system, chimney, agitator, inlets, outlets, |
| Describe the influence of grain to water ratio on the mashing process. | the weight of grain to water ratio in the mash is and important consideration for the brewer since it affects the mash vessel capacity, amout of lautering sparge wahter available and ability to mash high gravity beers. |
| how would you define a thin mash? | Grain to water ratio of 1:4-1:5 Positive influence on amylolytic enzyme activity. |
| List the enzymes involved in the cell wall breakdown during mashing. | Endo-B-1,4- gulcanase Endo-B-1,3-glucanase B-glucan-solubilase Phosphatase |
| List the pH and temperature optima of protein degrading enzymes. | Endo Peptidase 3.9-5.5 pH 45-50 Celsius carboxy peptidase 4.8-5.6 50 Celsius amino peptidase 7.0-7.2 45 Celsius di-peptidase 8.2-8.8 pH 45 celsius |
| Which enzymes will degrade starch in the brewing process | B-amylase A-amylase limit dextrinase maltase saccharase |
| how can you check saccharification in the brew house? | Iodine test. |
| List 5 Advantages of mash acidification. | - Better enzyme activity -Lower wart viscosity -Better protein breakdown and trub separation -Improves flavor stability -Fewer diacetyl problems. |
| List 5 Disadvantages of mash oxygenation. | Results in: -Poor protein breakdown -Poor taste and poor flavor stability -beer ages faster - causes oxidation -less protein precipitation. |
| define brewing adjuncts. | adjuncts are another starch or sugar source used in brewing to supplement malt as a source of wart extract |
| list 3 major types of adjuncts and where they are used in the brewing process. | Rice, corn and wheat. they are all used in the mash |
| List 3 quality tests for dry adjuncts. | test for: -moisture, extract and protein. |
| List 2 advantages of adjunct use. | -Less expensive extract source -helps with flavor stability needed for long distances shipping |
| List 2 disadvantages of adjunct use. | -Need for different types of equipment -Difficult to match existing all malt beer styles |
| why does a brewer need a cereal cooker for unmalted cereals? | a mash cooker is needed to gelatinize the starch cells the same way malt starches are in mash tun. |
| What enzyme sources may be used in a cereal cooker? | Alpha amylase from fungal or bacterial sources may be used in the cooker. |
| List typical steps in a (mashing) schedule for a cereal cooker. | -Water and malt mixed at 38-48 Celsius -Mixer on high speed-ground adjuncts added -once mashed-in raise temp by 1-1.5 Celsius/minute -liquefaction rest at 74-76 Celsius for 10 minutes -raise to a boil for 12 mins |
| Define lautering | Lautering is essentially a strainer or colander used to hold insoluble materials to filter mash and to separate spent grains from wort. |
| List 3 factors that may affect lauter tun performance. | -grist grind whether its to fine or to course. -wort viscosity -bed depth |
| What is the purpose of Vorlaufing? | to settle grain bed and clarify wort. |
| Why is the temp of the sparge water critical? | too low-viscosity and time of run off increases Too high- leach polyphenolic componds, lipids or unconverted starches. |
| what are the negative effects of cloudy wort runoffs. | cloudy wort makes for harder filtration, poorer foam retention, darker in color, less flavor stability, and inferior tastes. |
| what are the objectives of mash filtration systems? | to produce clear wort for the kettle Higher extraction efficiency of wort from grains less oxygen pick-up in wort quick equipment turnaround |
| List 3 advantages and disadvantages of the mash filter. | Advantages: Less brew house space, use higher levels of adjuncts, and higher extract yield. Disadvantages: More expensive to maintain, cannot see what your doing, not as flexible with mash volume changes. |
| List the operational steps of a mash filter. | -Filter preparation -Filling the filter and first wort run-off -first compression -sparging and second wort run-off -final compression -spent grain discharge. |
| List the main components of wort. | Water, hop constituents, Carbohydrates, nitrogenous constituents, tannins, salts and minerals. |
| List 4 changes in wort that occur during boiling. | pH decreases, color increases, wort is sterilized, and enzyme destruction. |
| what is break formation? | the flocculation of proteins and other materials during the boil |
| What are some disadvantages of direct kettle heating? | -Over-boiling -excess color formation in the wort -flavor changes -heavily soiled heating surfaces |
| What parameters of wort should be checked during or after the boil? | -wort clarity -amount of casting wort -extract in wort -check for starch residues -check pH levels -check wort gravity |
| CALCULATING TOTAL EVAP RATE FORMULA: C=[(A-B)/Ax100 | A=Volume of wort before start of boiling B=Volume of finished wort after boiling C=total evaporation rate |
| CALCULATING SPECIFIC EVAP RATE FORMULA: C=(AX60)/B | A=Total evaporation rate(%) B=wort boiling time(minutes) C=Evaporation rate(%per hour) |
| Define trub or break | is an insoluble precipitate, consisting of coagulated protein, polyphenols and carbohydrates. |
| why do brewers want to remove trub? | Trub can smear the yeast cell membrane, causes beer flavor instability, and causes haze in beer. |
| what are some differences between hot and cold break? | Hot trub forms at hotter temps during wort boil where cold trub forms when wort is cooled for fermentation. |
| what methods can be use to remove hot break | using a whirlpool where wort is rotated and trub can settle out. Hot wort filtrations with D.E., could use a centrifuge. |
| what are some causes of poorly sedimenting trub? | Interferences in the settling of trub in the whirlpool -Sedimentation speed is to slow - excessive shear during transfer to whirlpool. |
| List 3 cold break removal methods | -Skimming open fermenters -Use fermenters with foam chambers. -flotation tanks |
| what are the purposes of wort cooling? | to pitch yeast at proper temp. -minimize microbiological breakdown -use to recover energy. |
| what are the 2 most common coolants used in wort cooling | water and glycol are the two most common coolants |
| list 3 advantages of a plate cooler | good heat transfer less space usage relative microbiological integrity |
| what minimum cleaning velocity should be used on the wort side of the color | cleaning fluid velocities must be about 1.5 times faster than wort flows. |
| why do brewers oxygenate wort? | brewers oxygenate to make sure there is enough D.O. for yeast growth. |
| If wort temperature is raised how does this effect oxygen solubility? | the warmer the wort temperature the less soluble oxygen becomes |
| Is bubble size important for oxygen solubility in wort? | Yes, smaller bubbles stay suspended better than bigger bubbles. |
| Air flow rate=(brew size x D.O. desired x .35) / time to cool | O2 flow rate = air flow rate/ 5 |
| List 5 reasons for taste testing. | -Quality maintenance -Consumer research -Panel training -Comparison with competition -Monitor changes |
| before holding taste panels what decisions must be made? | -reason for the test -type of panelist group -type of test |
| Name 3 general types of sensory panels. | Paired comparison Duo-trio test Triangle test |
| How is a duo-trio taste panel set up and what is a taster suppose to do? | One sample is clearly identified as the control and taster will look for degree of similarity and preference. |
| What training measures should be undertaken with in-house panelists | make sure everyone knows the difference between sour, salty bitter and sweet. Identification of some common flavors. detection thresholds. |
| what must be included in a beer recipe | -List of ingredients and their quantities -tell us how and when they should be combined -temperature control at all stages of the brewing process. -Yeast handling -the fermenting/aging and filtering regiments. |
| List 3 types of recipe formulations that a brew must do. | -Creation of a new beer recipe -Revision of an existing beer recipe -Modification of existing beer recipe to create a new beer |
| how will brewing equipment have an effect on recipe formulation? | equipment can give a brew limitations. may not know how to use the equipment, or you may not have a cereal cooker so there for you need to use all grains and no adjuncts. |
| Where would a brewer look for information on the performance of a yeast strain. | with the yeast suppliers, or if you can find another brewer using the same yeast strain. |
| What are the names of the strains of ale and lager yeast? | Ale: Saccharomyces cerevisiae Lager: S. cerevisiae var carlsbergensis. |
| list the principal functions of yeast in the production of beer. | -Fermentation -Production of flavors -Also adds nutrition |
| How do brewers yeasts reproduce? | Vegetative and sexual reproduction. |
| What are the yeast nutrients in wort? | fermentable sugars, amino acids, oxygen, fatty acids, sterols. |
| Define yeast growth. | The transport and assimilation of nutrients by yeast followed by the integration of component cellular functions leading to biomass increase and eventual cell division. Pretty much take up nutrients, use then and make babies. |
| List the 3 phases of yeast growth. | -Lag phase -Log phase -Stat phase |
| What is flocculation? | The spontaneous aggregation of yeast cells into clumps which settle out of suspension and either sediment or rise to the surface. |
| What two substances have an effect on wither yeast goes to respiration or fermentative mode. | sugar and glucose |
| what are the 2 Primary fermentation metabolites? | Ethanol and co2 |
| Define the term beer spoilage. | Any change which results n an uncharacteristic flavor, odor or appearance of beer. |
| What characteristics make beer resistant to spoilage bacteria? | Beer can resist the growth of spoilage bacteria du to the low pH, low O2, ethanol, and hop extracts. |
| Name 3 gram positive spoilage bacteria. | -Bacillus -Lactobacillus -Pediococcus |
| Define wild yeast in a brewery. | Wild yeast is any yeast that's not what you intended to brew with that ends up in your wort. |
| List 4 general detection methods for beer spoilage organisms. | -Microscopy -Selective Media -Membrane filtration -Biochemical (bioluminescence) |
| Define 'Quality' | a measure of excellence or a state of being free from defects, deficiencies and significant variations. |
| What is the difference between Quality control and Quality assurance? | Quality Assurance is process oriented and focuses on defect prevention; while quality control is product oriented and focuses on defect identification. |
| What exactly is meant by the term pure culture? | its a single strain of a yeast species grown in isolation from other yeast strains and free from any microbiological contaminants. |
| Name and describe a method for a)isolating a pure brewing yeast culture and b)preserving it. | To isolate a pure brewing yeast culture you could use serial dilution, and dilute a mixed culture all the way down to 1 cell/ml, then you can put that single strain in a slant and preserve it in a freezer around -80 c |
| List 3 aspects to be considered when propagating brewing yeast in the plant. | -Wort sterility -Contamination issues -Temperature- gradual decreases. |
| List 3 reasons why brewers propagate yeast. | -To avoid mutations -To produce sufficient yeast in good condition to pitch a fermenter -Minimize contaminations |
| Name 3 stresses which can affect brewing yeast? | -Temperature shocks -Alcohol toxicity -Nutrient starvation |
| List 2 yeast viability tests and 2 yeast vitality tests | -Viability tests: -Plate/slide culture -Methylene violet(stains dead cells) Vitality tests: -Acidification power test -Intracellular pH method |
| Explain why yeast glycogen levels need to be maintained high during storage. | Glycogen levels need to be maintained to keep the yeast viable. |
| What are the main aims of yeast pitching? | To minimize lag phase, suppress bacterial growth and initiate rapid fermentation and to pitch consistent levels of viable cells. |
| Describe a method for acid-washing of yeast | Use food grade mineral acid, chill yeast and acid to the same temp. make sure the stir continuously and make sure you eliminate or minimize ethanol. |
| Name 3 disadvantages of acid washing. | could effect viability, vitality and flocculation, wont kill wild yeasts |
| what must be done before the beginning to sterilize equipment? | You must purge out the co2 as to not ruin your equipment. |
| Fats and protein are attacked best by alkalis T or F. | True |
| What 5 factors impact on the efficiencies of detergent performance? | -Concentration -Detergent to soil ratio -Temperature -Mechanical action -Time |
| Name the key attributes we want in an ideal sanitizer. | -we what it to be effective against a wide variety of micro organisms at low concentrations. -Want it to be non corrosive and non-staining -Readily available and inexpensive. |
| Heat is effective in sanitizing and sterilizing. what is a strong negative aspect of using heat? | It cant very detrimental to equipment by wearing it down quicker. |
| oxidizing sanitizers are grouped in four ways. what are they? | Chlorine based, Iodophors, peroxide based, and Gluteraldehydes. |
| what are the main way a surface active sanitizer works? | Acts by surface action. by disrupting cell membranes. |
| What is a Q.A.C.? | is quaternary ammonium compounds. -They are a surface active sanitizer, that disrupt cell membranes are non toxic. |
| Why must we be concerned about the environment when cleaning and sanitizing? | A lot of the chemicals could be very hazardous to nature |
| List 5 characteristics of ale yeast. | -Ferment ate higher temps -Faster fermentations -Increased fermentation by-products -Higher ester levels |
| list 5 fermentation control points | -Wort composition -Strength of wort -pH of wort -Temperature -Time |
| Why are cylindro-conical fermenters now the brewery standard | they save space, easer to draw off yeast. |
| Name 2 advantages of continuous fermentation. | Can produce beer a lot quicker, and saves on capital expenses. |
| List 4 possible disadvantages of high gravity brewing. | -Reduced efficiency of brew house extract and hop utilization -Losses cost more -Capital equipment needed for dilution stream handling -Longer fermentation times |
| What is clean in place? | CIP is a system put in place to clean, sanitize, disinfect, and sterilizing brewing equipment. Used on equipment that can not be removed and cleaned manually. |
| List the advantages and disadvantages in vessel cleaning. | Advantages:- Cheap Disadvantages:- Short cleaning radius -Hard to remove and clean if the systems not meant to. -Shadowed areas |
| List 3 tank cleaning problems. | -Shadow areas - Surfaces not smooth(wont clean that area) -Design does not allow for easy drainage |
| What are 3 requirements in pipeline cleaning? | -Clean 1.5 times faster than wort flow speeds -Run cleaning solutions in opposite direction of wort flow. - |
| List the steps in normal CIP cycle. | -Purge CO2 first -Pre-rinse to clean most soils out. -Detergent wash. -Rinse -Acid wash -Rinse -Sanitize |
| What are the major components in blended caustic? | -Caustic-used in removing fats and protein -Gluconates for hard water control and solubilizing mineral deposits -Phosphonates as threshold inhibitors to control hardness precipitation -Surfactant to lower the surface tension-help solution penetrate the soils for the chemicals to attack the soils. |
| What care should be taken storing iodine-based sanitizers? | Keep iodine-based sanitizers away from acids, alkalis and heat. |
| Name 5 Fermentation flavor compounds. | -Acids -Alcohols -Esters -Aldehydes -Ketones -Phenolics |
| How many flavor compounds have been identified in beer? | 950 400 from yeast |
| What is the flavor of iso-amyl-acetate? | the flavor is banana. |
| List 4 Factors effecting ester production. | -Different yeast strains -Wort gravity -Ferm. temps -Oxygen levels |
| If beer has high diacetyle after fermentation what can be doen to reduce it? | Allow the beer to warm slightly in the aging tank to a moderate temp for the yeast, or you can use the krausen method |
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