ContentsUnit 1: Brewing Process...............................................................................................................................1

Unit 2: Basic Brewing Biochemistry.............................................................................................................2

Unit 3: Brewing Water.................................................................................................................................4

Unit 4: Hops.................................................................................................................................................7

Unit 5: Malting...........................................................................................................................................10

Unit 6: Adjuncts.........................................................................................................................................13

Unit 8: Milling............................................................................................................................................15

Unit 7: Mashing.........................................................................................................................................17

Unit 9: Lautering........................................................................................................................................19

Unit 10: Wort Boiling.................................................................................................................................21

Unit 11: Wort Clarification, Cooling and Aeration.....................................................................................24

Unit 12: Yeast.......................................................................................................................................27

Unit 13: Yeast Growth and Fermentation...................................................................................29

Unit 1: Brewing ProcessBeer: beverage from alcohol fermentation of water extract of malted/unmalted cereal grains

Ingredients:

Water (94-96%)

Malt - malted barley, primary source of sugar

Hops - perennial, climbing plant native to northern temperate regions; adds bitter flavor + aromas preferred since the 7th century

Yeast ale “top fermenting”

Lager “bottom fermenting”

Saccharomyces cerevisiae “sugar fungus of beer”

Brewing Process: mill, malt, later, wort boil, clarify, wort cooling/ aeration/ pitch, ferment, harvest yeast, store/age, filter, bottle, package, check quality

Milling – crushing to expose inner part of grain

Mashing – wetting with worm water solubility starch effect of enzymes from malting, time and temperature

Lautering – separating liquids and solids to make separate grains and wort

Boil – wort sterilized, and concentrated hops are added, and proteins coagulate

Clarifying – ____ transferred to whirlpool, “trub”/ hot break settles for removal; trub is hop biomass and proteins

Wort, cooling/ aeration – after sterile air/ oxygen is injected while cooling to promote aerobic yeast growth

Fermentation – yeast grows, generates heat and CO2, aroma and flavor compounds, and when anaerobic, alcohol

Harvesting – yeast from fermentation is collected and stored in a yeast brink for re-pitching

Aging – “green” / sour beer is matured at cooler temperatures; time depends on style of beer

Filtering – removes yeast and remaining proteins for desired brilliant clarity

Bottling – beer is moved to pressurized tanks where level of carbonation can be adjusted packaging – cans bottles or keys

Quality checks include >100 sensory and chemical analyses on each batch throughout process

Unit 2: Basic Brewing BiochemistryCompounds are made of molecules, molecules of atoms, atoms of neutrons, protons + electrons

An electron is 1/1837 mass of proton or neutron

A molecule is made of molecules held together by chemical forces

Atomic shells hold 2, then 8, then 8 electrons

Biological substances made of mostly C, H, N, O, S, and P

Can be shown with Lewis Structures: C (4) H (5) O (6) P (5) S (6)

Covalent bonding common in organic molecules

Ionic bonding common in inorganic molecules

Water: universal solvent, critical for brewing, needed for life, water molecule bonds are extremely strong

Organic molecules that are important for brewing are:

Alcohol

Aldehydes

Acids

Esters

Ketones

Aldehydes (ketones) have carbonyl (carbons)

Organic acids (esters) have Carboxyl (carbons)

Raw materials include: malt, hops, adjuncts

Keep organic compounds are proteins/ enzymes, carbohydrates, lipids, phenols, and polyphenols

Haze is caused by complexes of proteins, often with polyphenols

Proteins – made of amino acids, key element is Nitrogen

Amino acids, to common for brewing, especially yeast nutrition and growth

Form primary structure polymer backbone

Secondary – twisting together of primary chain (sheets/ helix)

Tertiary – folding of protein

Quaternary – combining of multiple tertiary structures to for complexes

Brewing proteins mostly come from malted barley, broken down in malting/brewing, component of beer foam and haze, and affect flavors by individual amino acids

Enzymes are protein catalysts activity affected by temperature pH and pressure depolymerize proteins/ carbohydrates, cell walls, and can release phosphate into brew water proteinase, carohydrase, glucanase

Carbohydrates maltose – glucose – glucose source of energy for yeast starch is storage molecule most follow Cx(H2O)n or (CH2O)n

Dextrins – oligosaccharides that are too big for break down by yeast

Lipids – hydrocarbons, most important are fatty acids

Improve yeast viability, inhibit formation of less pleasant acetate esters, decrease foam, participate in staling reactions “freshness” try to remove from brewing as much as possible

Glycerol

Lipid glycerol + fatty acids

Oleic acids oxidize to soapy/ goaty compound

Lipids come from yeast, oxidized hops, long chain/unsaturated fatty acids from malt

Phenols come from malt, hops, yeast metabolites, contaminated water residual chlorinated water residual chlorine based sanitizers

Polyphenols

Anthrocyanogens, catechins, tannins impact clarity and taste, catechin (a flavon – 3- ol) can be antioxidant some polyphenols can enhance oxidation

Haze – simple malt + hop phenols = tannins

Tannins + proteins complex, is insoluble and can lead to permanent haze

Oxidized flavonoids + tanoids polymerize

Unit 3: Brewing WaterWater minerals make certain styles of beers, such as Burton – on – Trent pale ales, Munich dark lagers, and Pilsin light lagers

Water types: groundwater, surface water, riverbank filtered water, waste waters – must match local drinking water regulations and specifications

Used for brewing ingredient, cleaning, rinsing, cooling, steam generation, clearing food – contacted surfaces

1 hL of beer needs – 6 hL of water

Water treatments:

Sedimentation/filtration; removal of dissolved compounds, disinfection (filtration, boiling, UV radiation, chemical treatments, i.e. Cl)

Microbial regulations include removal of Escherichica Coli, Coliform microorganisms, streptococci ( O, h//OOm/)

Quality evaluated by color, turbidity, temperature, pH, electrical conductivity (EC), and taste

Water – polar

Salts used in brew water: CaSO4 • 2H2O, CaCl2 •2H2O, Mg SO4• 7H2O

At < 100 ppm Na+ gives slightly sweet flavor

CO2 + H2O_______ HCO3- + H+ dissolves soil minerals

Mineral ions react with H+ to affect wort pH

Cations: H+, Ca2+

, Mg2+, Na+

, K+, NH4

+, Mn2+

, Fe2+/3+, Al3+

Anions: OH-, CO32-

, HCO3-, Cl-

, SO42-

, NO3-, NO2

-, PO4

3-, SiO3

2-

Ca 2+

Most important for brewing cofactor for enzymes in mesh improves trub fermentation (yeast flocculation), precipitates calcium oxalate “beer store” which can cause gushing beer in packaging, decreases mash/ wort pH by Ca(PO4)2 precipitation, (want Ph 5.2 – 5.6) want 40 – 60 ppm in malted mash, about 1/2 Ca lost in mashing therefore 80 – 120 ppm is needed in mash tub

Mg 2+

More soluble then Calcium salts, less effect on wort pH bitter or sour taste in final beer, cofactor for fermentation enzymes, want 10 – 15 ppm, usually no additions needed

CO3 2- , HCO3-

Want low levels because they prevent decrease in wort pH contribute to alkalinity, want < 20 ppm carbonates or will need to add acid

Cl-

Gives mellow flavor and palate fullness

SO42-

Drier, more bitter flavors; source of SO2 (burnt matones) and H2S (smell of rotten eggs) in fermentation beer has a pH of about 4; Wort pH is 5.2-5.6

Alkaline pH lowers malt enzyme activity and yields, hard polyphenol taste, slower fermentation, higher hop bitterness yield during boil

Can de-carbonate, add mineral acids, use ion exchange columns (water softener)

Hardness

Ca and Mg dissolved salts, temporary is Ca/Mg (HCO3)2, is reduced by boiling CO2, adding lime can precipitate CaCO3; permanent is Ca/ Mg + SO4, Cl, NO3, reduced by ion exchange; based on {Ca} in ppm < 20 > 120 measures in degrees of hardness in US 1 ͦ= 1 ppm CaCO3

Water hardness treatment

Ca(HCO3)2 + Δ CaCO3 + CO2 + H2O

Lime: Ca(HCO3)2 + Ca2(OH)2 2CaCO3 + 2 H2O

Demineralization - ion exchange, reverse osmosis

Remove Fe and Mn by aeration (oxidation)

Remove organics by activated carbon

Remove excess CO2 by aeration or marble filter

Pilsmers require very soft water, ion exchangers include resins, zeolites, clays in mush K3PO4 + CaSO4 Ca(PO4)2 pH lowers

High pH is better alpha acid is isomerization but less balanced bitterness taste

Acidification usually by H3PO4 or lactic acid

Burter on Trent: very hard, very alkaline, lots of CA

Munich: lower in hardness, Ca, Mg, and SO4-

Pilsen: very low dissolved ions and hardness when adjusting brew water chemistry, meat Mg target first with MgSO4 , then SO4 target with CaSO4 , then Ca target with CaCl2

Residual alkalinity relates hardness to pH

RA – non-carbonate hardness carbonate hardness

Total alkalinity (ppm CaCO3) x .056 - Ca(ppm Ca2+) x .04 - Mg(ppm Mg2+) x .033

Wort pH = 5.59 + .028RA

RA can be positive or negative; want pH 5.2 – 5.6 brewing salts can be added to grain; acids added to mash water or sparge water

Want 5.4 – 5.6 first pinnings; pH of 5.3 – 5.4 for kettle work and want RA between 0 - 10

Unit 4: HopsThe first beer was brewed in 4000 B.C. Sumer, then Egypt, and it is doubtful that any hops were used.

In central Europe in the 5 -7th century, hops were used instead of oak bark and cloves

8th Century Spalt/ Franconia – oldest hop growing area

Hallertau – 1st hop gardens in 859 A.D.; mid 18th Century, documented statistics about hop growing

Hops were grown in 30 countries, especially Germany, United States, Czech Republic, Slovakia, and Poland as exporters to 170 beer brewing countries, about 43 tons of imported 1997 German purity law (1576): hops, yeast, malt, water

Hops provide bitter aroma, biological stability, colloidal stability, and foam stability

Female plants are used for beer productions to increase yields

Canabiaceae humulus lupulus (cultured) & Canabiaceae humulus mas ( wild ) – hemp family

Female and male plants have separate blossoms. Female plants build up cones: spihalve, lupilin, lupulin glands, leaves; glands contain resins

per hL of beer, 100 -300 grams of raw hops are needed

Grown in mild climate with enough rain (35 – 55th parallel)

Vertically oriented wires, 4-7 m tall

Harvested in August in Europe, special equipment dried from 80% moisture 10% moisture by weight %: cellulose 40 – 50, water 6- 10, protein 15, ash 10, alpha acids 2-15, beta acids 1- 10, essential oils 0.5 – 5, polyphenols 2-5, fatty acids trace .25, monosaccharides 2, pectins 2

Aroma varieties added late in boil: Hersbrucker, Hallertau, Fuggle, Oregon, Willamette, Select, Parle, Golding, Tradition, Cascade

Traditional bittering: Northern Brewer, Hallertau, Super Steier, Premiant; high alpha: Magnum, Taurus, Nugget, Target, Columbus

German

Tettnonger, Puk - mild aroma, unusually soluble alpha acids;

Hallertau – Mittlfrueh - susceptible to wilt;

Hersbrucker Spaet - good aroma, more disease resistant

United States

Mt. Hood - 1989 USDA Oregon breeding program) used as replacement for some European hops;

Liberty – 1981 USDA Oregon;

Willamette – 1976 USDA Oregon;

Fuggle – daughter, growin in U.S. and B.C.;

Cascade – 1972 USDA OR, dark green long cone

United Kingdom

English Golding – herbs in 13th century;

1st hep garden- 1520 Westbere;

Canterbury - grown in 1st century typical of English aroma/flavor;

Fuggle – 1861, was brought to the United States < 1900

Boiling hops solubilizes and isomerizes alpha acids, solubilizes polyphenols, coagulates proteins, timing in boil affects bitterness (alpha- acids) and aroma (essential oils)

Hops total resins hexame hard resins

Soft resins beta acids

Flocculate lupulones don’t flocculate

humulones

alpha-acids converts to more bitter/ soluble iso – alpha – acids; melting 100 – 65 C, soluble in water ( 450 ppm at pH of 5.9 and 100 C) in wort ( 84 ppm, pH= 5.2 at 100 C)

flocculates during fermentation, isohumulone soluble in wort ( 2000 ppm, pH = 3.4, 100 C)

lupulone

melting at about 92 C, no solubility in water or wort oxidation procucts are soluble

Isomerization converts 6 C rings to 5 C ring, two different stereo isomers ( cis and trans )

Alpha acid concentration - Magnum 12.6, Nugget 10.1, Perle 6.2 Hallertau 4.2

Oxidation of hops gives rancid, “cheesy” off flavors, moved from baled hops to pelleted, Nitrogen, vacuum packed hops stored under refrigeration

(HS) Hop storage Index: measures degree of oxidation, polyphenols contribute body and astringency and many ingibit oxidation

Sunlight can deteriorate humulones to 3 – methyl – 2 – butane – 1 triol skunky, “ light struck” can hydrate unsaturated side chains of iso – alpha acids or beta acids

Reduced Isomerized Hop Extracted (RIHE)

3 Basic RIHEs: dihydro – iso- alpha acids, tetrahydro – iso- alpha, hexahydro – iso – alpha acids

Bitter value – alpha acids + beta fraction / 9 all from soft resins; beta in fresh hops are about 10% total in brewing, about 70% of bitter is lost 50% during isomerization, hot trub, cold trub

20% during pH drop, precipitation, adsorption, stabilization, filtration durint fermentation.

In Germany, certain areas are sealed to prevent mixing of hope varieties, 1930 hop origin law “German Seal Hop,” cultivation area, seal distinct, class and variety

Quality control before processing: pesticides, contaminants, water content, stems versus leaves, cone cover leaf content, % of disrupted cones, other particulates

Hop products give higher bittering yields better economics easier storage and handling, lower volumes, standardization, higher stability

Normal powder 90

Powder Enriched powder 45

Raw hops extract Isomerized powder

Extract powder powder + extract

Extract KG(SiO2)

Baled hops disadvantages: perishable, bulky, lupulin is heterogeneous – hard to sample and control, whole hops have poor utilization

Hop plugs – used in non-brewing and U.K. dry hopping compressed hops into 1” x ½”, .5 oz

Hop pellets – break bales, remove extraneous material, ( Type 90) hammermill, pelletize powder, vacuum/ hert pack type 45 removes fibrous part of cone, ^ ½ weight stabilize pellets: add 2 – 3% MgO, alpha acids form magnesium salts; used to make isomerized pellets

isomerized pellets – stabilized pellets stored at 50 C for 1-2 weeks to convert 90 – 95% of alpha acids most economic form of bittering, 55-60% utilization bittering preserved without cold storage aroma preservation still needs refrigeration so concern about effects on flavor and aroma alpha acid utilization better because lupulin glands are broken open during milling; milling removes sticeks, stems, stones, etc. lowering the risk of clogs or damaged values

non- isomerized extracts: began in the U.S. in the 1960’s uses hexane and CO2; in Europe, ethanol is also used

Undiluted resin has alpha content, 30 – 50%, can be diluted with corn syrup

Isomerized/ fractionated/ post fermentation extracts: alpha acids separated from extracts, heated with aqueous alkali or Mg salts; yield only pure potassium salts of iso-alpha acids

>95% utilization for bittering or post-fermentation most widely used and most stable

Can be difficult to flavor and match or get fullness some use beta fraction extract to compensate isomerized extracts usually used as supplements can also come in reduced isomerized forms for light stability; has form enhancement properties alpha acids from liquid CO2 extraction have lower solubility (need ethanol solvent/ dosing) enhance foam, 1.7 x more bitter, protection from light with more bitter than reduced products

Unit 5: MaltingBarley has characteristic flavor, protective husk, high enzymatic potential, favorable protein to starch ration, husks provide filter medium during Lautering first cultivated since near East 7000 – 8000 B.C. , fertile crescent Gramineae family, Hordeae tribe, Hordeum genus,

Hordeum vulgare (6 – row): high protein, high enzyme activity, low extract, central kernel, and 2 lateral kernals

Hordeum districhon (2-row): low protein, low enzyme activity, high extract, 2 alternating kernals barley breeding focused on agronomic yield, disease resistance growth time, enzyme potential, short/strength straw, lower protein, faster malting

Example composition: water 14%, starch 54.5% , N-force extract 12%, protein 9.5%, lipids 2.5%, ash 2.5%, other 5%

Both species of barley have physical and biological standards for brewing performance husk is part of leaf system protecting embryo and endosperm, mostly insoluble, increases final beer viscosity and phenolic “harshness” in taste; minerals provide nutrients to yeast under husk, pencorp with chlorophyll and waxy, testa semi permeable membrane allows water passage, aleurone layer contains reserve lipid, protein, polysaccharides and releases hydrolyteic enzymes (gibberellic acid),

Endosperm: starch, glucan, arabinoxylan

Germination – malting modification

Embryo: living tissue dormant during harvest

Scutellum – separates endosperm from embryo epithelial layer transports enzymes to endosperm during germ halver, acrospires (hop) moves towards top while rootlet moves towards bottom

Germinative capacity is most important barley parameter and refers to production of enzymes and modification on endosperm; should be > 95% to get good saccharification during mashing, higher final attenuation, good low – molecular N in wort, lower viscosity; increases with post – harvest dormancy

Nitrogen depends on variety, growth conditions and fertilization levels, barley protein 8-13.5%

European 2 rows < American 6-row ~ Canadian 2-row lower protein gives smaller malting losses, higher extract concentrations, lower enzyme concentrations, lower amino acids for yeast nutrition, lower from protein

barley extract are water soluble components: carbs, proteins, minerals; measured after “lab mashing” (boiling then hydrolytic enzyme exposure; use to compare malt varieties but does not indicate extract in finished malt

most dangerous barley infections are fungal; lower yield, excess protein, decreased extract, premature enzyme synthesis, gushing

Steeping process begins with water uptake moisture from 12% - 48%; and 30%, significant increase and homogeneously, 44% vigorous enzyme activist/ fast modification of endosperm dry steeping alternates time when barley is under water to increase activity to give faster water uptake uptake better with high

water temperature, small kernels, low protein, short dormancy, barley variety, crop year, abrasion, water sensitivity

Steeping washes grain, removes “float-ables,” provides oxygen to kernel, remove CO2, remove growth inhibitors from husk

1) 4-6 hours, 12 C, <30%, an every hour, 10 – 20 minutes CO2 decreases under wet conditions2) 4-20 hours, 15-17 C, <32%, continuous CO2 reduction3) 2-4 hours wet, 12-15%, <38%, air every hour, 10-20 minutes CO2 decreases4) Dry 18-22 C, <40%, continuous air5) Wet 12-18% C, <42%, 1-3 hour, 10-30 minutes CO2 decreases

Aeration cleans barley by overflow, oxygenates during, wet periods, > 5 ppm O2 in steep water, >5 m^3/h/ton

CO2 extraction starts immediately after drain period, keep [CO2 ] < 0.5%, >9m^3/h/ton

Parameters 14 – 18%, 44-48% humidity, oxygen degradation of proteins, hemicellulose and gums protecting starch and depolymerizes some of the starch

Germination enzymes

Cytolytic enzymes: Alpha amylases, Beta- amylases, limit dextrinases

Proteolytic enzymes: endo – petidases, exo-peptidases

Equipment must control temperature and humidity in red

Example: Saladin box includes fan room, humidification room, germination box, bed support, turning machine rail and carriage, cable drum, exhaust air duct

Kilning

Reducing moisture of malt from 45% “green” to 3.5 – 4 % terminates modification, stabilizes malt components, develops malt flavor and color (roast)

Phases

1) “free” increasing drying temperature 45 – 65% C, full air flow 4,000 – 5,000 m^3/ton/hr2) “forced” full air flow3) Curing about 50% airflow, stepwise temperature increase to 80-85% C, 4-5 hours4) Cooling

Growth terminates >40 C, <20% moisture, then enzyme activity, chemical reactions continue

Color forms from amino acids and sugars melon oidins good for mouth feel, flavor, flavor stability

S-methyl-methionine di-methyl-sulfide evaporates liberation of acid phosphates and melanoidins lowers pH

Drying process characterized by fresh and exhaust air temperatures; use in exhaust temperature indicates grain bed is dry (no heat of vaporization needed)

Kilning systems classified by type and number of floors, direct v.s. indirect heating, combination with germination

Example: single deck kilning (1st floor) , highest flexibility to adjust air and temperature parameters 18-20 hours, 250 – 400 kg malt/ m^2 , 400-5500 m^3/ ton * hour flow, 25 – 40 kWh/ ton/ 0.8 – 1.05

Mils kCalorie/ ton direct heating; 33-48 kWh/ton/1.05 -1.2 milskcal/ton for indirect heating

Finished malt must be stored >21 days before brewing to slightly increase and equilibrate moisture stored in silos, bins, or malt floors must maintain hygiene and deculmed/ polished

Important malt qualities: high extract, easy processing, good carbohydrate profile (fermentable v.s. non-fermentable)

Good wort separation and high filterability functions of husk size and retention, low steely distal ends, proper endo – glucanase activity

Filterability also affected by viscosity and [ p- glucans]

Protein modification affects haze and foam potential DMS can be redhued by choosing 2-row, good kiln airflow, high kiln temperature (evaporation)

U.S. malt standards – American Society of Brewing Chemists

see list of malt specifications

Unit 6: AdjunctsSupplements starch/sugar source in brewing besides malt common adjuncts are corn or nice – or wheat, barley, sorghum, cane sugar, rye, oats

Seen outside German Relinheits gebot regions law passed to prevent misuse of adjuncts

Belgian brewers use candy sugar in U.S. 6-rows barley use resulted in excess protein and husk creating haze and cong shipping flavor problems adjuncts give lighter bodied taste; ore-less expensive malt to adjunct 1900 – 1935 80/20 1935 – WWII 70/30

1950 – 1970 60/40 1970 and 45/55

Adjuncts can affect flavor; it > 20% will give different beer characteristics

Milled, meal and grit products need a cereal cooker; flaked, torrified and microlized adjuncts are pre-gelatinized and are added to the mash like malt syrups are added to brew kettle

>30% adjuncts can lead to yeast nutrient deficiency

gelatinization: hot water used to swell/ separate starch cells

liquefaction: enzymes (alpha -amylases) reduce starch molecule

size by cleaving off glucose – mash fluidizes

brewers rice 82 C

brewers corn 78 C

wheat 60 C

Potatoes 55 C

Cost of adjuncts increases with amount of pre-processing; syrups are most likely to stress yeast in Germany only barley and wheat malts allowed non – barley malts are usually not considered adjuncts

(wheat, rye, oats, sorghum), give taste and head retention

cereal cookers are modified mash mixers: more steam jacket area, high shear, high speed mixer (<60 rpm) to prevent clumping and scour surfaces; high viscosity final water/adjunct ratio should be 3:1 (300 L water to 100 kg cereal or 1.15 bbl water: 100 lb grain)

Malt high in enzymes (high DP, >120 lintner) is added at 10% weight of adjunct; can be mash liquid infusion from surface of mash mixer (250L = 100 kg malt) or alpha-amylase from fungal or bacterial sources can be used in cooker instead of malt

Fungal enzymes are more heat stable, add right bettor adjunct addition not boiling malt husks reduces harsh taste

Example: Cereal coller scheme: water and malt 38 – 48 C, mixer at high speed to add ground adjuncts, increase temperature 1-1.5 C/minutes to 74 – 76 C, liquification rest for 10 minutes, increase to boil for characteristic tire too much boil causes starch retro-degredation

Mash mixer adjuncts

Flakes made by steam softening and hot rolling to gelatinize starch (corn, rice, wheat, barley, oats, torrified adjuncts use temperatures (260 C/ 500 F) to “pop” starch and denature about 90% or protein (corn, barley, wheat)

Micronized adjuncts are heated to 140 C (285 F)

Using ceramic tiles that emit IR radiation

Kettle adjuncts

Dry sugar (corn, core); dry corn sugar can how maltose) be purchased small scale with similar sort sugar profile syrups (corn, wheat, barley, sucrose); most wet-milled corn

ASBC lists tests for dry adjuncts: moisture, oil, extract, protein, ash, color, foreign matter

For symps and sugars: clarity, color, extract, moisture, pH, acidity, starch test, protein

For taste, make “tea” of adjunct

Advantages: increase capacity without additional equipment, easier high gravity brewing, lighter bodied/flavored beers, more beer styles, less expensive (bulk), more stable beers

Disadvantages: may need different equipment, difficult to match all-malt beer styles, expensive (small quantities) yeast might need supplementation

Unit 8: Milling Milling is to increase surface area, crack outer husk (longitudinal best) separate husk and endosperm, crush/disintegrate endosperm, create optimal filtering materials for Lautering, work quick to prevent oxidation

Million process is mechanical to support chemical and biological processes during mash, affect mash quality and extract yield; lower malt quality equals more milling importance transport malt from maltster to brewery, unload malt to storage, cleaning, conditioning, weighing perfectly milled malt has no uncrushed kernels, majority of husks plait with freed endosperm, uniform endosperm size, minimum of powder trade off: want husk intact as possible, endosperm as fine as possible, minimize tan flour

Husk is mostly insoluble cellulose, elastic, difficult to mill/pulverize, provides fiberbed for filtering, affects color and taste with polyphenols, harsh/ bitter compounds, silicates, proteins; too fine of fiber gives too slow of filtering, crushed grist quality depends mostly on condition of husk for endosperm, low modification during malting means fine milling will be required

Collect dust for explosion protection, cleanliness, microbiological safety, employee health malt transport and handling bulk transport done by ship, rail or truck

Small quantities ship in pallet bags or standard bags malt is unloaded by belt conveyors, bucket elevators, screw conveyors, pneumatic systems, for lifts, humans malt cleaning is done with vibrating/ shaker screens, cyclones, and magnets

Conditioned dry milling – is used to reduce mechanical stress on grains outer surface by adding moisture to soften husk, lubricate flow, and reduce shattering mostly screw conveyors injecting steam as hot water before dry milling; improves yield, reduces dust

Mill types – dry, wet, hammer, rotary disk

2-roll dry: simplest, cheapest, easiest, requires uniform, well modified malt, slow capacity, 15-20 kg/cm width/ hr, 160-180 roller speed also used to grind raw cereal adjuncts

4-roll dry: one pair for pre-crushing, 2nd pair for husk rolling, size separation in between used in breweries lager then brewpubs, still requires well modified malt, foster throughput

6-roll dry: for large breweries, 3 pairs with screens, largest degree of control and flexibility, high throughput robust, minimal maintenance

Wet milling – combines and washing, some enzymes already active, requires stainless steel and integrated AP cleaning, no longer manufactured; replaced by extensive steeping

advantages: no dust, intact husk, can use less modified malts, increased extract and efficiency

disadvantages: hard to operate, high maintenance, increased oxidation due to pumping, large units

Rotary disc milling – often used with high pressure mash filters created grist is very fine slice filter clothes (in mash) already does filtering (no held for intact husk), less expensive than roller mills, very high extraction efficiencies if used with mash filters

Grist assortment – crushed malt particle size factors (screening size) husks, coarse grits, fine grits, flour affected by mill settings and type, malt type and conditioning, mill maintenance, auxiliaries see ASBC grist fractions for lauter ten ad mash filter visually check grist daily, screen once per week most mills have built – in samplers ensures rollers are parallel, rollers/ bearings not worn, size with feeler gauges, must contra in feed flow if uncrushed kernels roller gap is too big, malt feed rate is too fast, rollers are wear-grove, flour should only be white as you are grinding husks

Unit 7: Mashing

Wort extract is substrate for yeast made from beer ingredients by time, pressure, and temperature and enzyme activity during mashing and boiling. Extract includes fermentable sugars, free amino nitrogen (FAN), vitamins, minerals, trace yeast nutrients

Some wort constituents are needed for beer but not used by the yeast: unfermentable sugars, dextrin, soluble proteins, some inorganic substances

Original extract: total concentration of soluble components in the wort prior to fermentation

Real extract: total concentration of soluble substances after alcohol is evaporated and replaced with DI water

Apparent extract: total concentration without accounting for the lower density of ethanol

Goal of mashing is to seductively solubilize molt components; depends on equipment, missing grain to water ration, schedule, pH, minimal oxidation

Mash agitation needs to get vertical and horizontal mixing to get even temperatures (no burning/ undercooking) and too much shear due to baffles/ ladders/ obstructions, high speeds, poorly designed, and placement of impellors

Trying to avoid farming beta-glucan gel which can be problematic for Lautering and beer filtration

Mash tun: mash vessel without mixing blades and unheated, used for mashing and lautering

Often combined with vosmasher that thoroughly wets/mixes the grain on the way into the mash tun by screw angle sometimes pre-mashing is just stirring grain into water grain to water ration impacts vessel size and amount of spurge water available

Thick mash 1:2 1:2.5 good proteolytio enzyme activity to increase protein peptide FAN

Thin mash 1:4 1:5 good amylolytic activity to intensify starch dextrin fermentable sugars malt enzymes must be brought into solution and with controlled pH, time and temperature four enzymes break down cell walls: endo – beta- by glucanase, endo beta – 1,3 – glucanase, Beta-glucan solubilase, phosphatase – decrease viscosity and improves access to starch granules protein degredation affects yeast nutrition, colloidal stability, foam stability; 40 – 60 C, peak at 50 C + 30 C endo-peptidase, carboxy -peptidase, amino-peptidase, di-peptidase (inner, carboxyl end, amino end, dimers)

Amylitic starch breakdown affects alcohol content and beer body

B- amylase: alpha 1,4 ends to maltose

Alpha – amylase: alpha 1,4 inner bonds to dextrin

Limit dextrinase: alpha 1,6 to dextrin

Maltase: maltose to glucose

Saccharase: sacchrose to glucose, fructose

Mash schedules – enable rest times covering specific enzyme activity ranges for malt quality and beer type

Infusion mash: whole volume is kept at defined temperature in mash tun from 35 – 75 C through proteases, B-amylase and alpha – amylase

Double mash – after 30 minutes protein rest, mash separated, track decotion mash heated to 70 C the boiling, then returned to mash tun

Triple mash: most common for under modified malts, 3 boils of 33% trick mash 33% thick nash, then 40% lauter mash (4.5 – 5)

Mase decotuer mashes: higher energy consumption, more color and more phenolic substances; modern more – modified malts enable nearby all infusion mashes

Starch degradation measured by iodine test small volume of mash mixed with a drop of iodine; color indicates degree of saccherification blue – purple – red – clear as chain length decreases from >4.5 to < 9 with 8 to 1.5 brades in complete conversion causes lower fermentable extract, attenuation, yield; and negatively impacts flavor haze stability depending on brewing water, may need to acidify mash to get pH to 5.4 – 5.6 and wort to 5.3 – 5.4 acidification leaders to higher attenuation, better enzyme activity, lower viscosity ( quicker Lautering), better protein breakdown (trub separation), lighter color, optimal FAN, quicker diacetyl removal, improved flavor stability too much oxidation leads to poor protein breakdown and precipitation, turbid worts, less whirlpool trub separation, poor taste/ flavor stability, unchar bitterness, more lipoxygenase/ perioxidase activity for lipid oxygenation, fast beer aging (trans – 2 - nonenal), poor polyphenol composition, higher polymerization index

Unit 9: LauteringLautering is German “ablauten” to clarify / purify lauter tun is to settle and separate spent grains from wort solution, remove and clarify first wort, wash out solids Lautering performance: high throughput, efficient extraction of wort from spent grain, dear wort to kettle, minimum oxygen depends on malt quality; malt handing techniques, grist assortment, mash mixer performance, gentle mash transfer

1) Underletting: raise temperature to 76 C indulet water to deep viscosity low, removes air from false protein, prevent grain from clogging holes

2) Mash off: transfers mash by pump with low impeller speed/sheer for low ounces pick up, splash, even mash bed distribution; multiple entries in lauter tun

3) Grain bed composition: thin dough – lixe heavy particles, thick layer of coarse particles, thin layer of fire, gel – like particles; ideal thickness 35 cm to ensure quick flow

4) Vor lauting: letting work settle for 5 – 10 minutes, then pumping wort, back though top of bed to clarify first work; important to not disturb grain bed

5) Raking: level grain bed during mash transfer, loosen grain bed during runoff, make spent grain discharge easier; can be raised/ lowered and run at different speeds

6) Furst wort: at equilibrium sugar concentration, rakes maintain grain bed at defined height, wort level stays ~1 cm above grain bed

7) Sparging: washing grain bed after first wort runoff temperature at ~ 76 C, delivered evenly onto grain bed, if sparge too cool, increased viscosity/ runoff true too hot, get polyphenols and unconverted starch

8) Sparge in = wort out to maintain wort height above bed, too much raking/ too low raking can lead to turbidity, if wort level falls, grain bed can collapse sparge until needed kettle volume, last wort guidelines 12 P down to 1.5 P16 P down to 2.5 P“sweet water,” last runnings can be used in underletting

9) Remove spent grains using rakes; sell for animal feed10) Flushing/ cleaning: “chase water” at sparge temp to flush line to boil kettle (must account for

volume) Underplate flushing to remove from below false bottom manual hosing and flushing grain out valves to make sure they close securely tradeoff between speed and quality K, Ps, ΔD, µ

Lauter tun alternatives – some methods to improve Lautering have had mixed results for clarify, oxidation, and flavor profile

mash filter

Darcy’s equation

PA

µR P, pressure; A, cakes surface area; µ, wort viscosity; R, cake resistance

mash filter maximizes A, decreasing mash bed thickness, can also press out last running through increased pressure

Advantages: less space, more forgiving for adjuncts >25%, faster runoff, grist can be fewer crushed increases yield 1%, good quality beer, lower capital investment

Disadvantages: not as flexible with mash volumes, operator cannot view directly, costly gaskets/cloths, similar operators, skill requirements, better for higher throughput and standardization

Spent grains analysis, total available extracts measured with spent grain plus malt enzymes

Soluble weak wort pressured out of spent grain and liquids density measured

Extractable/ releasable equals a total available – weak ~ 0.8%

High soluble value equals a poorly modified malt, too five grinds, too short Lautering, bed compaction, runoff too cold, unequal filling of mash filter chamber

High extractable: poorly modified, too coarse grind, too short mashing

Unit 10: Wort BoilingWort composition

Carbonydrates (91 – 92%) with fermentable sugars (68 -75%): fructose, glucose, sucrose maltose, maltriose

Nitrogenous compounds (3-5%): amino acids, peptides, poly-peptides/proteins, nucleic acids

Remainder: polyphenols/ temins from husks add hops, salts from water and malt, humulones, iso -humulones, other hop-derived organic material

Boil is energy consuming and evaporates water, distills volatiles, sterilizes wort, denatures enzymes, precipitates proteins/ tennins “break,” extracts and isomerizes alpha-acids, form reductive substances, lowers pH, increases color, decreases surface tension

Evaporation rate in 5-10% per hour (target 8) for 1 – 2 hours must balance energy use, wort color and water use distillation includes water, dimethyl sulfide (from malt), malt volatiles, hop volatiles, (from bittering hops)

Sterilization of must bacteria happens in 15 minutes and is aided by lower pH; delays between runoff and boiling increase clonces of contamination

Boiling denatures remaining enzymes from mash – off and Lautering

Break formation – is a visual indicator of effectiveness of reduction of high new proteins which influence colloidal and foam stability

Helical structures are disturbed, proteins shift from hydrophilic to hydrophobic and gain positive charge, polyphenols have negative charge and combine with proteins aggregation and precipitation includes carbohydrates

Hop components solubilize, combine in break, and evaporate

Polyphenols dissolve and contribute to break Hop oils (harsh and bitter if oxidized) evaporate Alpha and beta – acids one more soluble and bitter than alpha – acids Malliard reaction between amines and simple sugars forms reducing compounds and colored

compounds Active part of reductones are dienol groups reductones directly correlated with color may act as

anti-oxidants to preserve flavor Carmelization is reaction of secondary amines with complex sugars and increases color Oxidation of tamins forms red/brown compounds and reduces level of phenolic anti- oxidants

Past kettle designs were direct heated over wood, coal, oil or gas; and tended to cause super heating which led to over – boiling, excess, color, flavor changes

Hydro - boiling was sometimes done using pressurized hot water (160 – 170C) but need large pumps, valves, etc. and were not as efficient as steam heat transfer

Steam heating designs include jackets, internal coils, percolators, internal shell and tube (internal calandrias), and external shell and tube (external clanchias) heat exchangers provide controllability of steam temperature, pressure, and rate. Most kettles were copper but now are stainless steal many are cylinchical but some are rectangular

Most small systems use steam jackets with 20 – 25% headspace and proper As to V ratios to get rolling boil too hot steam causes excess color, fouling and large steam plant requirements

Newer systems combine steam jacket for pre-heating and calondria for the main boil

- Can save energy through stack condensation, MUC or TVC, and potential pressure boiling to reduce time

External calondria

Pros: improve bitterness yield, better coagulate precipitable protein, control wort circulation, have lower saturated steam pressures, control evaporation rate/ temperature, remove aroma – spoiling volatiles, lighter color, lower pH, cleaner taste, and better flavor stability

Con: Requires circulation pump, more radiative heat losses, higher initial costs, greater shear forces on floors

Internal calondria

Pro: lower cost, no extra electric power needed or radiative losses, controllable temperature/ evaporation rate, low saturated steam pressure, controlled over goaming , closed door boiling so no stack fan needed

Con: More difficult cleaning, wort can overheat expecially at start of the boil creating excess color and caramel flavor

New developments include pumped wort – thin film evaporation “Merlin system” (Steinecker/krones) and dynamic low pressure boiling (Huppmann)

Additives include Irish moss or carrageenan for aiding trub formation; (from past) tannin, potassium metabisufite, calcium sulphate, activated carbons, diatomaceous earth paramerters to check include wort clarity, “casting wort” amount, extract in wort, presence of starch residuals

Inadequate boiling leads to:

lower gravity extract level in brew with larger volumes

insufficient hot break (trub)

difficulties with fermentation and filtration

premature chill haze formation

>Spec DMS levels

Poor hop utilization

Over boiling leads to: higher gravity and lower volume

Trub break up and redistribution/haze/flavor issues

Excess malliard reactions (hydroxymethyl terfurol)

With bready/ cardboard flavor

Harsh bitterness

Increased color

Unit 11: Wort Clarification, Cooling and AerationBreak or trub is an in soluble precipitate of coagulated protein polyphenols and carbohydrates. Break forms hot, trub forms during cooling

Trub can contribute to poor yeast health; precursors to unpleasant flavors (esp. fatty acids), haze in beer, initial acceleration of fermentation due to increased surface area for CO2 release, not yeast lipid assimilation hot break are larger particles, cold trub has more proteins, polyphenols and bitter substances

Hot break levels should be lowered from 400 – 800 mg/L to <100 mg/L must balance costs, process time, wort clarity, wort/yeast quality ~1/2 of cold trub is practical to remove

Hot wort filtration done with coarse diatomaceous earth, creating costs and potential microbiology problems

Centrifugation: consistent effectiveness, few losses, expensive, requires complex maintenance, shear may break up particles;

Coolship: shallow settling vessel, microbiology and O2 concerns, if settling time too long (>4 hours). Get Dms (cooked veggie) off flavor

Whirlpool: settling vessel aided by rotation of wort, considered most practical, acceptable costs, good removal in < 1 hour, if done correctly, has minimal wort quality impacts, whirlpool works as cyclone through a reduced nozzle entry tangential to container wall creating rotation, causes accumulation at boundary layer between bottom and wort; rate is function of P.G.F centrifugal

Whirlpool should have H/D ratio of 0.7 – 1.0, inlet pump sizing 4-6 wort volume, inlet velocity <3.5 m/s to reduce shearing, inlet should be ~1/3 up from bottom to lower aeration, tangential and flush with inside wall, whirlpool bottom 1-2 from horizontal retains less wort in trub pile, sumps for trub not recommended, wort outlet drawoff ~1/2 height until wort is 5-10 cm from trub pile

Trub pile should be loosely compact and not disintegrate, draw off wort should be <10 EBC turbidity, drafts off from pile should be steady trickle without causing pile to slide or release trub pieces, often discorded with spent grains

Poor sedimentation can be caused by deficient Lautering, high solids content to brew kettle, obstructions in whirlpool, torus eddies/ secondary currents in whirlpool, small trub particles due to excessive shear caused by high velocities, long pipes, tight plumbing turns/ T-connections, incorrect centrifugal pumping (impeller design, high speed, cavitation)

Whirlpools can be improved and settling time reduced by installing a concentration 30-60 cm above bottom, ½ - 1/3 whirlpool diameter to reduce torus eddy effects

Whirlpool times from emptying brew kettle to start of wort chilling: 10 – 15 minute transfer, 20 – 30 minute rest, 75- 90 minute cooling; DMS can occur if time is > 2 hours cold trub removal is difficult to remove but can reduce bitterness; flavor usually better Fuith some (40 – 60 mg/L), cold trub; more important to remove for mild and lighter beers cold trub removed by skimming open fermenters after collapse of high krauesen foam (open fermenters rarely used),

Foam chamber fermenters – collect krauesen foam with trub sticking to fermentor roof (extra capitol and clean kg),

Floatation tank – after cooling before fermentation uses excessive aeration to trap cold break in foam and the foam removed (most common method today), remove sediment trub with sediment yeast in cylindro-conical tanks

Wort is cooled in 60 – 90 minutes (as quickly as possible to reduce energy needs and microbial breakdown) from ~95 C to 6-20 C pitch temperature

Coolant options:

Chilled water: plentiful, efficient utilities use, limited temperature minimum

Brine: CaCl2 or NaCl in water, can get to – 2C, corrosive

Glycol: propylene in water (25 – 33%), can get to -4C, must common

Ammonia: used as refrigerant (liquid to gas), danger if leaked new refrigerants (i.e. Freon) have lower temperatures and non-toxic

Wort chillers

Open plate: wort trickles our open ridged plates with cooling medium flows inside plates, up to 5 ppm DO aeration, energy inefficient, potential for microbial contamination

Double pipe: wort flows in inner pipe, coolant in amulus,

Four coolant: 1 wort ratio

Shell – in – Tube: wort in tube bundle, coolant in shell; 3:1 ratio

Closed plate and frame: thin dimpled plates in series enable high heat transfer coefficient and 1:1 ration in countercurrent flow; wort must be clear and plate order correct wort outlet temperature can reach down to T, water in + 5C (single stage)

In two stage plate and frame, first section uses brewing water and 2nd stage coolant; used to warm brewing water, Twort, in – Twater, out ~ 10C, Twort,out – Twater, in ~ 3-4 C,

Wort 95 C 14 – 15 C pitch temperature

Water 85 C 10 C 0C recycled coolant

Flow ratio (brewing water + sparge water) x (1.10 to 1.20) = 1

Volume wort

Wort aeration – yeast growth, especially lipid synthesis, needs oxygen, mostly used up in ½ - 3 hours, needs 8 -9 ppm dissolved oxygen is only time oxygen is desirable in brewing process

Oxygen solubility in wort is proportional to O2 partial pressure and total pressure, and inversely proportional to temperature, bubble size, beer gravity as temperature increases 5 -15 C, O2 solubility decreases 9.5 – 7.3 mg/L

Air and Oxygen flow rates to reach 9.5 – 6 mg/L (5 20C)

Are 3.3 2.1 L/hL air: wort of 0.7 – 0.4 L/hL O2: wort

Generally, use 2-3 X excess to account for non-uniform bubbling and mass transfer limitations in dissolution, use 5 – 10 x excess in floatation tanks

Air/oxygen must be clean and oil free (cannot use oil compressor), dry (to prevent bacteria/ mold growth in plumbing; can use refrigeration below dew point or ammonia or silica drying), Sterilize by 0.2 µm membrane filter, precisely metered, very finely aerated for small bubbles or venture, sufficient pipe length before pitch to prevent O2 toxicity to yeast due to high local concentrations

Unit 12: YeastPurposes: fermentation of sugars into ethanol and CO2, formation of beer flavors (desirable mature beer aromas and undesirable “green beer” aromas), release of nutrients into beer (amino acids, vitamins, anti-oxidants, trace elements)

Yeast taxonomy: Eukaryota, Fungi, Eumycota, Ascomycota, Sacchromycetes, Saccaromycetales

Sacchromyces cerevisiae (top fermenting) for ales, malt beers, wheat beers – form cell clusters

Saccharomyces carlesbergensis (bottom fermenting) for layers – do not form cell clusters

Morphology: macroscopic: small – medium size colonies, white, beige to brown, soft to porcelain-like surfaces, round

Microscopic: round- oval cells (5 – 10) x (5 – 12) µm, sometimes elliptical to cylindrical, seldom extended cells appear in singles, pairs or clusters, may see asci spores (1 -4 per asci)

Cell structure: organelles include nucleus (genetic material and transcription, must double chromosomes for budding), cell membrane (transportation/selection), cell wall (stability), mitochondria (cell energy, ATP, production/respiration), ribosomes and endoplasmic reticulum (protein production), vacuole (energy or materials storage)

Metabolism: two main paths alcoholic fermentation and respiration; can ferment glucose, fructose, sucrose and maltose; some can ferment malt triose; cannot assimilate nitrate; no tolerance against, .01% cycloheximide (actidion), or lysine or CuSO4 – agar.

Reproduction: usually by vegetative (asexual) budding, rarely by (sexual) formation of ascospores

Mitosis/ budding under pleasant conditions gives identical mother and daughter cells; forms budding scars only reproduction technique desired in brewing process

Meiosis/ ascospore formation under unpleasant conditions, fusion of ascospores leads to DNA recombination can be caused by low pH, insufficient nutrients, shear stress “asci” membrane containing ascospores

S. carlsbergensis can 100% ferment raffinose, ferment melibiose, low respiration power, no growth in 37 C incubator, 5 -14 C and 8 – 12 day fermentation, strongly flocculate to powdery, yeast crop always on bottom

S. cerevisiae can not ferment melibiose and only 33% raffinose, 40 – 75% higher respiration power, can grow at 37 C, 15 – 30 C and 2-4 day fermentation, weakly flocculates to powdery, and crop is usually on the top (not always)

Powdery bottom fermenting yeast stays suspended, poorly harvests, ferments faster, high attenuation suppresses competitors, good “green” flavor reduction, poor clarification ( yeasty flavor) flocculant bottom – fermenting yeast settles well to give good yeast harvest, slower fermentation and lower attenuation, clarifies well, less reduction of “group” flavors must balance yeast growth ( for repitching) and fermentation (stress)

Yeast nutrients: carbo/ fermentable sugars ( Carbon source, energy), Nitrogen sources ( amino acids/ peptides for protein biosynthesis), structure/ metabolism co-factors (Potassium, Sodium, Magnesium, Zinc), O2 (respiration, biosynthesis of cell membranes), vitamins, fatty acids, sterols good brewing yeast equals rapid and efficient fermentation with minimal growth, consistent flavor/ aroma, stress tolerant (EtOH, osmotic pressure, temperature), appropriate flocculation, high viability and vitality for repitching, stable genetics

Unit 13: Yeast Growth and FermentationGrowth: transport and assimilation of nutrients, followed by integration of component cellular functions leading to biomass increase and budding

Fermentation: anaerobic conversion of fermentable sugars into ethanol, CO2 and flavor fermentation by-products

Fermentable carbohydrates: glucose, fructose, menose, galactose, maltose (z-glucose), sucrose (fructose – glucose), raffinose (galactose – glucose – fructose), malto triose (3 – glucose)

Slow growing yeast requires high concentrations to be pitched and slows fermentation process

Separation usually occurs when mother and daughter cells are same size – can initiate budding cycles resulting in ~ 3 X mass of yeast than initially pitched lager yeast cells have a mean life span of 20 generations, buds must form in scar- free areas

Typical fermentation population is 500% un- budded cells, 25% single 0 budded mother cells, 25% multi – budded cells older cells ferment poorly, flocculate less, reabsorb diacetyl poorly, utilize sugar less effectively, less stress tolerant

Want mix of young and aged fractions as unbudded cells are also poor fermenters

Healthy/fresh yeast has fairly deer interior, thinner cell wall, and mere regular size and shape (5 – 10 µm D) older yeast has granuala interior, thick walls, bud scars, and larger accuoles

In lab, begin with 10 6 cells/ ml at a lag phase, increase to ~ 107 cells/ml during log phase, then stationary phase

Lag phase: no multiplication, adaptation to environment and synthesis of enzymes, oxygen needed for lipid/ sterol synthesis, in breweries 10 – 20 hours

Log phase: exponential multiplication, ale fermentation 48 – 60 hours

Stationary phase: exhaustion of nutrients, use of stored glycogen begins, accumulation of metabolites and development of unfavorable growth conditions

Lethal phase: starvation / death more than reproduction, some cells die and autlyze, yeast flocculates

Growth factors: pitch rate, level of dissolved oxygen ( too little oxygen reduces yeast population and lengthens time for complete fermentable extract consumption), temperature, flocculation pattern affects settling time

Glycolysis: wort sugars pyruvate

~ 30 ATP, CO2, H2O (aerobic) 2ATP, CO2, ethanol (anaerobic)

Yeast would much prefer aerobic respiration

Glucose 1 pyruvate acetaldehyde + CO2 ethanol

2 ADP -> ATP 1 NADH 2NAD+

2NAD+ AVADH

Uptake: facilitated diffusion glucose, fructose

Saccharose: break sucrose with invertase, then uptake

Active transport: permease mones maltose/ malto triose, then hydrolyzes by maltase or maltotriase to glucose

Single cell colony isolation: streak yeast slurry onto agar plate, re-sterilize loop, streak original application, re-sterilize loop, streak secondary streaks, etc.

Yeast propagation enables sufficient yeast in good physiological condition for pitching, reduces chance of mutated yeast or contamination, off flavors like H2S or dacetyl, altered flocculation patterns, less maltotriose recommended to propagate after 8 – 10 generations for lager yeast usually slope culture, to 100 ml shake flask ( 12 P, 24 hours, aeration), 1 L shake flask ( 12 – 16 P, 24 – 48 hour aeration) , 50 L cornelius tank ( 12 – 16 P), 48 hour aeration, 1 barrel of wort in plant

When prorogating, must use aseptic techniques, sterilized growth media, never increase volume more than 10 – fold per increment, aerate and keep slightly warmer than in plant to encourage faster growth rate

In plant, propagation is Cornelius tank 1 hL ( 20 C) 10 hL ( 18C) 60 hL ( 16C) 900 hl (12C)

Targeting rapid growth ( less lag phase ) and 1 x 106 cells/ ml P