Institute of Brewing and Distilling General Certificate in Brewing (GCB) Section 1 An Overview of Brewing Practices.

Transcription

1 Institute of Brewing and Distilling General Certificate in Brewing (GCB) Section 1 An Overview of Brewing Practices. Candidates will be expected to describe the principal stages of the brewing processes, to visualise them as flow diagrams and to demonstrate a practical knowledge of plant layout. A Definition of Beer:- In its basic sense, beer is an alcoholic beverage produced by the fermentation of sugars derived from malted barley and flavoured with hops. There are some minor differences where malt is supplemented with adjuncts or where the hops are replaced by other flavours, but this definition would be recognised by the majority of people round the world. The manufacture of all alcoholic beverages utilises the ability of yeast to ferment sugar into alcohol. SUGAR YEAST ALCOHOL Wine is made from grapes, cider from apples, whereas in the case of beer, the sugar is derived from malted barley and flavour and character comes from the addition of hops. The full process also involves preparing the immature or green beer for consumption. MALTED BARLEY HOPS SUGAR YEAST 'GREEN BEER' BEER FOR SALE CARBON DIOXIDE 1

2 GCB Section 1.1 General knowledge beer types Different types of beer. Different areas around the world have developed their own types of beer. The variations have come about through a combination of the materials available for its manufacture and the tastes of the consumers. Lager is by far the biggest proportion of beer sold. Its delicate flavour comes from:- The use of a malt that is relatively undermodified and lightly kilned. A relatively low bitterness. The use of a bottom fermenting yeast. Cold maturation. Ales are produced mainly in the United Kingdom and the Republic of Ireland. Their flavours come from:- The use of a well modified and biscuity flavoured malt which is sometimes highly coloured. Sometimes they are very bitter. The use of a top fermenting yeast. Ales come in various forms, bitters, pale ales and mild beers. Wheat beers are lagers produced from the use of malted wheat instead of malted barley. Stouts are very dark in colour and richly flavoured from the use of highly coloured malts or roasted barley. 2

3 GCB Section 1.2 General knowledge - raw materials and processes. Malt. The malt used for brewing invariably comes from barley although it is possible to malt other cereals like wheat and sorghum. Cereals are the seeds of the plant and they contain a store in the form of starch and the means of converting that starch into digestible food. When the seeds germinate, they either convert starch into sugars or they develop the appropriate enzymes to do this. The malting and brewing processes exploit this so that the starch is converted into sugars that yeast can ferment. Malting Barley The malting process STEEPING GERMINATION KILNING The seed is soaked in water to start it growing The barley grows under controlled conditions and the 'changes' occur inside the seed The malt is dried out and colour and flavour are developed Malt corns A detailed description of barley, malting and malt is given in section 2 Sweet wort production (raw materials). 3

4 Adjuncts. Although malt is the major raw material providing fermentable sugar, in some breweries it is sometimes supplemented with adjuncts. Adjuncts come in the form of other cereals like wheat and maize or in the form of sugar. They are used to improve the flavour and appearance of the beer, to increase the capacity of the plant or to save the costs of raw materials. A detailed description of the adjuncts used in brewing is given in section 2 Sweet wort production (raw materials) Water. Brewing water or liquor, the term used in many breweries, is very important, about 95% of beer is water. It must be free of any contaminants that would harm the flavour or appearance of the beer or the people who drink it. It must suit the character of the beer and the processes involved in making it. A detailed description of brewing water is given in section 19 Utilities - Water. Hops. Hops are added to beer to give it a bitter flavour and the floral aroma associated with the hop plant. The hop is a plant that develops bitter resins called α-acids and oils within glands around the base of the petals in the cone. The hop plant Resin (alpha acid) Cone leaf Cone Seeds These resins are dissolved when the hops are added to and boiled in the process. They remain as isohumulone which is a strong flavour component of the finished beer. A detailed description of hops is given in section 4 Wort boiling. 4

5 Milling, Mashing and Conversion:- Beer production starts in the brewhouse where the malt is processed to release fermentable sugars. MILLING The malt is crushed MASHING Crushed malt is mixed with Water to start the conversion process CONVER- SION The starch is converted into sugar by the malt enzymes First the malt is milled to grind the starch into flour while protecting the malt husk because undamaged husk is required later. Milling Malt Mill Rolls Grist consisting of Flour Grits & Husk Then the milled malt or grist is mashed in with water under controlled conditions. This process brings the enzymes present in the malt into action and they convert the malt starch into sugar Starch being attacked by enzymes Sugar produced from starch ENZYME Detailed descriptions:- of milling is given in section 3.1 Plant operation milling ; - of mashing in section 3.2 Plant operation mashing; - of conversion in section 2.3 Mash conversion. 5

6 Wort Separation, Boiling Clarification and Cooling:- The sugar solution produced from the mash must now be separated from the malt husk, after that the clear wort is boiled and then cooled in readiness for fermentation. MASH SEPAR- ATION The malt husk is filtered from the wort BOILING The wort is stabilised and hops are dissolved COOLING The wort is cooled to a suitable temperature for the yeast There are several ways of separating the wort from husk, all use the husk as a filter bed. Spent Grain Clear Wort The wort is boiled to sterilise it, stabilise it by inactivating the enzymes, to improve its flavour and to dissolve the hop bittering materials. External heater Boiling wort 6

7 After the wort has been boiled, it has to be clarified because the boiling process produces solids called trub. Clarification usually takes place in a settling tank. Wort in Trub Clear wort out Typically, trub contains coagulated proteins and insoluble hop material. The clear wort is then cooled in a plate heat exchanger so that it reaches a temperature that suits the yeast that is to be added. Hot wort in Cold wort out The wort that leaves the cooler will contain the key constituents required by the yeast such as sugars for fermentation and other nutrients like amino acids derived from protein, vitamins and salts. Oxygen or air needs to be added to promote yeast growth. Detailed descriptions: - of wort separation is given in section 3.3 Plant operation wort separation ; - of boiling in section 4 Wort boiling ; - of wort clarification and cooling in section 5 Wort clarification, cooling and oxygenation (aeration). 7

8 The Role of Yeast in Fermentation:- Yeast is a single celled micro-organism that can survive with or without air. It takes in carbohydrates in the form of sugar to generate the energy it needs for life. When no air is present, yeast converts those sugars into alcohol and carbon dioxide. Oxygen CO2 Fermentable Sugar CO2 YEAST CELLS Alcohol Respiration 'growth' Fermentation 'no growth' The yeast used for brewing beer is carefully selected because it influences fermentation performance and the beer s eventual flavour. Some yeasts rise to the top of the fermenting vessel at the end of fermentation, these are used for producing ales. Some fall to the bottom of the vessel and these are used for producing lagers. Maintaining a healthy crop of yeast is very important and some breweries operate yeast culture plants to achieve this. A detailed description of the role of yeast is given in section 6 - The basic principles of yeast fermentation. The Fermentation Process:- During the fermentation process, yeast converts the sugars produced in the brewhouse into alcohols. The process starts when yeast is pitched into the wort and finishes when most of the sugar has been converted into alcohol and carbon dioxide. Yeast is cropped off at the end of fermentation so that it can be used again. 8

9 There are four stages in a brewery fermentation and these can be seen when the specific gravity of the wort then beer is plotted on a graph:- Specific Gravity Stage 1. Stage 3. Stage 4. Stage 2. Yeast cells rest and then start multiplying Yeast ferments the sugar into alcohol All the sugar has been converted and the yeast separates from the beer Time Fermenting vessels are designed to suit the yeast being used and the type of beer being produced, they come in various shapes and sizes:- Square shallow vessel Conical deep vessel Also heat is generated by the fermentation process and vessels are equipped with cooling systems. A detailed description of the fermentation process is given in section 6 The basic principles of yeast fermentation. Yeast Handling:- The yeast population grows by about five times during the fermentation process and it is cropped from the beer at the end of the fermentation. 9

10 The yeast crop has to be carefully looked after otherwise its health and performance will deteriorate with each successive generation. A healthy crop is maintained by aerating the wort, by always selecting the best yeast for pitching and by periodically operating a pure yeast culture plant. Best yeast for re-pitching Pitching Yeast Culture plant Fermentation Surplus yeast for sale Yeast must be stored carefully under cold conditions to keep it healthy and free from microbiological contamination. A detailed description of yeast handling is given in section 8 Yeast husbandry and handling. Beer Maturation, Conditioning and Cold Storage:- The beer is not ready for drinking at the end of fermentation, it contains substances that give it an unpleasant green flavour and it needs to mature before it can be packaged. 10

11 BREWHOUSE OPERATIONS CONVERTING MALT INTO SUGAR FERMENTATION CONVERTING SUGAR INTO ALCOHOL PROCESSING MAKING THE BEER MORE DRINKABLE PACKAGING PUTTING THE BEER INTO A COMMERCIAL PACKAGE The beer is matured in tanks or casks where the following changes take place:- Slow fermentation generates carbon dioxide to make the beer more lively with sparkle. Yeast absorbs or modifies unpleasant flavours. The yeast settles out and the beer clarifies. The beer is stabilised when stored at very low temperature so that it is prevented from forming hazes. The conditions under which the beer is stored for maturation depend on the type of beer being processed. Ales are sometimes be stored at warm temperatures for a short time while lagers are stored cold for longer. A detailed description of maturation, conditioning and cold storage is given in sections 9CSK (for Cask beer option): Beer maturation and cooling and 9C&F (for Chilled and Filtered beer option): Beer maturation, chilling and cold storage. 11

12 Beer Filtration:- Container (keg) beers, bottled beers and canned beers are packaged bright, that is they are filtered to remove any small particles like yeast or protein that would cause the beer to be cloudy. Cask beer is packaged with yeast in suspension and later treated with isinglass finings to clarify it. Isinglass finings Fermenting vessel Cask Bottle Maturation vessel Filter Bright beer tank Can Keg Filters work by a combination of sieving out the particles, trapping the particles in the complex pathways of a filter bed and absorbing the particles on filter aid. There are many designs of filter, all of which give an even flow of beer to the filter bed. Modern filters allow for easy discharge of waste from an exhausted filter. A detailed description of beer filtration is given in section 10C&F Bright beer preparation (for Chilled and Filtered beer option. 12

13 Packaging into Kegs, Casks, Bottles and Cans:- General. The main aims of packaging beer are to provide the consumers with beer in a convenient package of their choice and to ensure that the quality of the beer is protected during and after packaging. Consumer choice means that a range of beer packages are provided, for example kegs, casks, bottles and cans. The quality of the beer will have been established by the procedures adopted in the production operations described above, packaging operations are organised so that the quality is protected. The two main ways of protecting quality during packaging are Avoidance of contamination especially by air or micro-organisms. Microbiological stabilisation by pasteurisation or sterile filtration. Non-biological stabilisation by polish filtration. Packaging into Casks. Fermenting vessel Racking tank Filling Empty casks Full casks Cask Washing Conditioning (Maturation) The packaging operation works as follows:- 13

14 Empty casks are transported to the cask washer. They are inspected to ensure they are empty and fit for filling. They are cleaned with hot water. They are sterilised with steam. They are filled with un-processed beer containing some yeast. The full casks are transported to the cellar where they remain during conditioning. The casks are fined to clarify the beer prior to despatch. A detailed description of packaging beer into casks is given in section 10CSK Cask beer preparation and racking (for cask beer option). 14

15 GCB Section 1.3 General knowledge Technical Terms:- Absorption ABV Acetaldehyde Acetic Acid Acetobacter Adjunct Aeration Alcohol Ale Aleurone Layer Alpha acid Amber Malt Amino Acids Ammonia Amphoteric Surfactant Amylase Antifoam Ascorbic Acid Astringency Attemperation Attenuation Limit Auxiliary finings The process of material being swallowed up A measure of alcohol content by volume A flavour compound Acid (Vinegar) produced by bacteria A type of bacteria A supplementary raw material The addition of air to wort Compound formed by fermentation Beer brewed using UK methods Layer under the barley skin A bitter resin from the hop plant A type of malt Breakdown products of protein A gas used as a refrigerant A type of sterilant An enzyme that breaks down starch An additive used to reduce foaming Vitamin C used to reduce oxygen A mouth drying/bitter flavour A term for cooling down beer during fermentation A measure of the fermentability of wort A liquid used to clarify beer 15

16 Bacteria Barley Barm Ale Barrel Beer Bentonite Beta Glucan Bicarbonate Bitter Black Malt Blending Bloom BOD Body Feed Boiling Wort Bottom Fermentation Break Breakdown Small living organisms A cereal used to produce malt Beer recovered from yeast A measure of 36 gallons of beer or a 36 gallon cask An alcoholic beverage brewed from malted barley A stabilising agent A gummy material in barley An insoluble salt formed from carbonates A type of ale with a high hop rate A type of malt The mixing of beers to achieve quality A deposit on bottles A measure of effluent quality Powder added to the beer flow to aid filtration A process when wort is boiled A fermentation where the yeast subsequently sinks to the bottom The formation of solids in hot wort Water used to dilute wort or beer Liquor/Water Bright Beer Brown Malt Buffer Tank Calcium Calorie Beer that has been filtered A type of malt A tank used to control beer flow to the filter A metal important to yeast A measure of heat energy 16

17 Candle Filter Canned Beer Capacity Caramel Carapils Carbohydrate Carbon Dioxide Carbonate Cask Conditioned Beer Centrifuge Cereal Cooker Chill Haze Chloride Chocolate CIP Cleaning In Place Clarification Cling Coagulation COD Collagen Conditioning Conversion Coolant Copper A type of beer filter Beer packaged into can A measure of the specified throughput of plant Dark sugar A type of malt A food source An inert gas that causes fizz in beverages A salt dissolved in water Beer that matures in cask Equipment for clarifying beer Equipment for cooking cereal Haze formed when beer is chilled A salt dissolved in water A type of dark malt A method of plant cleaning Removal of particles from beer The adherence of foam to a glass Formation of solids during boiling A measure of effluent quality A protein important to beer clarification Maturation of beer when CO2 is formed A term to describe the breakdown of starch into sugar A liquid used to cool beer or wort A vessel for boiling wort 17

18 Copper finings COSHH Crown Cork Crystal Malt Customs & Excise De-palletiser Material added to the copper to aid clarification Regulations for handling hazardous material A cap for sealing bottles A type of coloured malt The regulatory body for duty collection Equipment for offloading packs from pallets Deaerated Liquor/Water Water with dissolved oxygen removed Decoction Mashing Detergent Dextrin Diacetyl Diastase Diatomaceous Earth Dissolved Oxygen A method of heating the mash A cleaning material Unfermentable sugar A flavour compound produced by fermentation Enzymes that break down starch A powder used as a filter aid A measure of oxygen dissolved in beer DMS Dimethyl Sulphide A flavour compound Dormancy Draught Beer Dry Hopping EBU Efficiency Effluent Endosperm Esters Ethanol The delay in the onset of barley germination Beer served from large containers often casks The process of adding hops to casks for aroma A measure of beer bitterness A comparison between actual performance and capacity Process waste The food store of the barley corn A group of flavour compounds The main alcohol produced by fermentation 18

19 Extract False Bottom Fermentation Filtration Finings Firkin Flash Pasteurisation Flavour Stability Foam Fob Forcing Test Formaldehyde Gelatinisation German Purity Laws Germination Glucose Gram Stain Green Beer Green Malt Grind Grist Gypsum Halogen Haze A measure of yield from the raw materials The slotted base of a mash or lauter tun The process when yeast produces alcohol The process of removing solids from beer A liquid used to clarify beer A cask containing 9 gallons Pasteurisation through a heat exchanger The maintenance of flavour quality The stable head/bubbles on beer Uncontrolled foam A procedure for microbiological analysis An aggressive sterilant The process of making starch accessible Reinheitsgebot. Beer is made from malt, hops, yeast & water only. The growth of seeds A simple sugar A procedure for identifying micro contamination Immature beer Germinated barley before it is kilned The degree to which malt is milled A term for crushed malt ready for use Calcium Sulphate present in Burton water A member of a group of chemicals including Chlorine A description of cloudy beer 19

20 Head Retention Headspace Hectolitre High Gravity Brewing Hogshead Hop Back Hop Extract Hop Oil Hops Horizontal Leaf Filter Hydrogen Peroxide Hydrometer Ice Beer Infusion Invert Ion Exchange Isinglass Isohumulone Jetting Keg Kettle Keystone Kieselguhr Kilderkin (Kil) The stability of the head on beer The volume above the beer in a bottle A volume of 100 litres Brewing where the OG in process is higher than the OG in package A cask holding 54 gallons A vessel for hot wort clarification An extract of the useful components of hops An extract of the oil of hops A plant used to 'bitter' beer A type of beer filter A mild sterilant An instrument for measuring specific gravity Beer which is frozen to concentrate its alcohol content A term for single temperature mashing A type of sugar A method of treating water The active ingredient in finings Isomerised hop resin Agitating beer in bottle/can before capping A metal container for holding beer A vessel for boiling wort A bung which holds the tap in a cask of beer A powder used in beer filtration A cask holding 18 gallons 20

21 Kilning Krausen Krausening Labeller Lacing Lactic Acid Lactobacillus Lag Phase Lager Lagering Lagging Lautering Lees Legionella Lipids Liquor Losses Lupulin Maize Flake Maize Grits Malting Variety The process of drying and cooking malt The head on fermenting beer The process of adding fermenting wort to fermented beer Equipment for labelling bottles The effect of foam clinging to a glass of beer as it empties An acid produced by certain bacteria A type of bacteria The early stage of fermentation Beer brewed using traditional 'Continental' methods The process of maturing lager beer Insulation material used on vessels to maintain temperature The process of wort separation The sediment remaining in a cask A type of bacteria found in water Fatty material in malt used by yeast A term for brewing water A comparison between volumes at the start and finish of a process A term for the bitter resin in hops Maize processed for brewing Maize milled for brewing A type of barley suitable for malting Maltose Sugar produced by conversion (see Brewing section 2.3) Mash Maturation The process of mixing malt and water Post fermentation processing 21

22 Medium Membrane Nourishment provided for microbiological growth A thin cover as used in a sample point Micro-organism A very small living organism (see Quality section 4.9) Modification Nitrates Nitrogen Non Biological Shelf A term to describe the change of barley into malt Chemical salts indicating water contamination Inert gas used to eliminate air or to give beer a stable head The time that beer remains free of non biological haze (see Brewing section 2.11) Life Non-biological Processes where microbes are not involved Obesum Bacteria Bacteria often contaminating wort (see Quality section 4.9) OG Oxygen Palletiser Pasteurisation Original Gravity. The specific gravity of wort before fermentation Gas required by living organisms but will cause beer staleness Equipment for loading packs onto pallets Procedure for heating beer to sterilise it Pasteurisation Unit A measure of the degree of pasteurisation (see Packaging section 3.2) Pediococcus Peracetic Acid Perlite ph Pils/Pilsner Pin Pitching Plate And Frame Filter Plate Heat Exchanger A type of bacteria affecting beer An effective sterilising agent A type of filter aid A measure of the acidity/alkalinity of a liquid A style of beer (lager) originally from Pilsen A cask holding 4.5 gallons The process of adding yeast to wort to start fermentation A type of filter Equipment for cooling or heating liquids flowing through 22

23 Plato Polish Filtration Polyclar PVPP Precoat Pressure Filter Primings Protein Proteolysis Pure Culture Unit of measurement of specific gravity expressed in percent Fine filtration of beer A beer stabilising agent Procedure for coating a filter with filter aid A type of beer filter Sugar added to fermented beer Complex organic matter important in malt quality The process of protein breakdown A procedure for providing high quality pitching yeast Quaternary Ammonium A sterilising agent Racking Recovered Beer Refrigeration Respiration Roast Barley Rough Filtration Saccharification Saccharometer Saccharomyces cerevisiae The process of filling casks/kegs with beer Beer recovered from yeast after fermentation The process of cooling beer down to low temperature The process of oxygen use by living matter An adjunct used in some dark beers and stouts Filtration to remove most particles from beer The process of starch breakdown into sugars An instrument for measuring specific gravity Yeast used in ale fermentation Saccharomyces uvarum Yeast used in lager fermentation Secondary Fermentation Continuation of fermentation at a slow rate Shelf Life Shive The time during which a beer retains its specified quality A bung that fits into the top of a cask 23

24 Silica Hydrogel Skimming Snift Sparge Spear Specific Gravity Spent Grain Spray Ball Stabilisation Staling Starch Starch Granules Steeping Sterilant Sterile Filtration Sucrose Sulphate Sunstruck Flavour Tannin Top Fermentation Torrified Wheat A material for stabilising beer Removal of yeast after fermentation The controlled release of pressure Water used to wash out extract from the mash The tube in a keg used for filling and emptying A measure of the relative density of a liquid Waste malt husk Equipment fitted to a tank for cleaning The process of processing beer to retain quality The process whereby beer loses its fresh flavour The carbohydrate food source of plants How starch is held in the barley endosperm Adding water to grain to start germination Material for killing micro-organisms Fine filtration where micro-organisms are removed A simple sugar A salt dissolved in water The 'skunky' flavour created when hopped beer is subjected to sunlight or UV light A substance in barley or other plants which affects beer stability A fermentation where the yeast subsequently floats to the surface Processed wheat used as a brewing material Trim Chiller A heat exchanger for cooling beer (see Packaging section 3.1) Trub Solids created when wort is boiled (see Brewing sections 2.5 & 2.7) TTT Trueness To Type A measurement of standardised flavour 24

25 Tunnel Pasteuriser Equipment for pasteurising small packs (see Packaging section 3.2) Turbidity Ullage A term for the cloudiness of beer Waste beer Vertical Leaf Filter Viability Vitamins Washer Water Softening Whirlpool Widget Wild Yeast Wort Yeast Yeast Cell Yeast Count Zymomonas A type of beer filter A measure of the number of live yeast cells Substances essential for healthy growth Equipment for washing bottles A process for removing water hardness Equipment for clarifying hot wort A smallpack insert for creating foam A type of undesirable yeast Product from the brewhouse before fermentation A micro-organism used to ferment wort A single unit of yeast A measure of the number of yeast cells in a sample A type of bacteria 25