[...]... Contamination and Beer Quality Brewery Spoilage Organisms Summary References 74 74 74 75 86 88 88 90 90 92 93 93 93 94 96 96 Chapter 5 Nutritional Aspects of Beer Beer Components of Nutritional Value Water Alcohol Carbohydrates Proteins, Peptides and Amino Acids Lipids Fibre Energy Value Minerals Vitamins and Micronu trien ts Phenolic Compounds Hop Bitter Acids Metabolism of Alcohol Risks and Benefits... the growing plant Green beer: Freshly produced beer immediately after the end of primary fermentation and before conditioning (maturation) Green malt: Barley germinated for between one and five days, before kilning, with a moisture content of at least 40% Grist: The term given to the mixture of coarsely ground malted barley, together with milled raw cereals and speciality malts (and barley) such as crystal... u-amylase and P-amylase, both of which can break down a-1,4 bonds A debranching enzyme, which can attack the 1,6 bonds, is also produced, but this enzyme is quite sensitive to heat and so is normally inactivated during malt kilning All of these enzymes must diffuse into the starchy endosperm and begin the process of breaking down the cellular structure (the cell walls) and the An Overview of the Malting and. .. while unmalted rice and maize grits may be used to improve the flavour stability of lightflavoured lagers The more intensely kilned malts (crystal, amber, or brown malts) are used to provide colour and flavour in traditional British ales, while roasted malt and barley are used in the darker porters and stouts (see Chapter 3) Like barley starch, wheat starch also gelatinises at 65°C Rice and maize starches... and Brewing Processes 13 SUMMARY To summarise, beer is made from an aqueous extract of barley grains which have been allowed to germinate Enzymes produced during germination digest the cereal starch to form sugars and these are then converted into alcohol by yeast Hops are added to provide characteristic flavours and aromas FURTHER READING 1 D.E Briggs, J.S Hough, R Stevens and T.W Young, Malting and. .. chapter, the determinants of foam, colour and clarity will be discussed in turn The main focus will be on foam and colour as a haze-free or bright beer is generally mandatory for consumer acceptance The presence of haze is often a result of the deterioration of beer with time and so is discussed in Chapter 4 A last point about consumer appraisal of foam, colour and clarity is that, with the current trend... bubble formation is by Beer Quality and the Importance of Visual Cues 17 cavitation This is a process whereby nucleation sites are generated by agitation of the beer, resulting in the instantaneous separation of beer and vessel Gas rapidly diffuses into these vacua, and the process of bubble growth and detachment can begin Ultrasound is a highly potent cavitation method and can result in very rapid, uncontrollable... proceed to completion during conditioning, since diacetyl and other vicinal diketones have Chapter 1 12 very low flavour thresholds and can impart distinct flavours, typically described as butterscotch Such flavours can be an essential element of, for example, some red wines and, to a lesser extent, some ales, but are undesirable in lighter ales and lagers Traditionally this conditioning period for lagers... horizontal position in a cool cellar without moving to allow any sediment that has accumulated from the finings, yeast and protein to fall to the bottom of the cask, allowing clear beer to be run off from above Such casks need careful and expert handling in order to provide bright clear beer and there are always great losses due to the beer being entrained with the sediments Possibly as a consequence of... (which give linear chains) and a-1,6 bonds (which give branch points) On average, each branch is made up of around 25 glucose units Amylose, on the other hand, is a linear molecule made up of up to 2000 glucose units linked by a- 1,4 bonds only (Figure 1.4) Both a-amylase and P-amylase can hydrolyse a-1,4 bonds P-Amylase attacks from the outer reducing ends of the amylopectin and amylose molecules, releasing . x0 y0 w0 h0" alt="" BEER: QUALITY, SAFETY AND NUTRITIONAL ASPECTS RSC Paperbacks RSC Paperbacks are a series of inexpensive texts suitable for teachers and students and give a clear, readable. M. Christie Beer: Quality, Safety and Nutritional Aspects by E. Denise Baxter and Paul S. Hughes Future titles may be obtained immediately on publication by placing a standing order. Information on this is available from the address above. RSC Paperbacks BEER: QUALITY, SAFETY AND NUTRITIONAL ASPECTS E. DENISE BAXTER Brewing Research International, Lyttel Hall, Nutjield,