Unit 24: Brewing Science Unit code: A/601/1687 QCF level: 5 Credit value: 15 Aim This unit will enable learners to apply knowledge of yeast physiology and microbiology to the biochemistry of malting, mashing and conversions, gaining understanding of fermentation and associated quality control systems. Unit abstract This unit has been designed to introduce the biochemical, microbiological and physical aspects of brewing technology. It has been designed in such a way as to allow flexibility of delivery. It will support and reinforce the knowledge and appreciation of fermentation systems, which will be vital to a career in brewing, fermentation technology or the licensed trade sector. The unit allows learners to apply this knowledge in a practical environment. It is assumed that, before undertaking this unit, learners have a working knowledge of the basic concepts of biological processes as in Unit 32: Nutrition and Diet. Learning outcomes On successful completion of this unit a learner will: 1 Understand fermentation systems 2 Understand the biochemistry of malting, mashing and conversions in the copper 3 Understand yeast physiology and microbiology 4 Be able to identify fermentation and associated quality control systems. 133
Unit content 1 Understand fermentation systems Microbial groupings: microbial range and form Unicellular fungi: importance to the fermentation process especially Saccharomyces species History of fermentation advances: metabolic pathways of respiration; dynamics of anaerobic respiration/fermentation; methods of controlling fermentation (top and bottom); principal steps in the brewing process 2 Understand the biochemistry of malting, mashing and conversions in the copper Barley physiology: choice of cereal; biochemical changes affected by the malting process Wort composition: biochemical/biophysical conversions Malting process: the enhancement of diastatic power; control of N 2 -content; development of colour Mashing process: the ionic balance of the liquor (Burtonization); factors affecting extraction and enzymatic conversion in the grist; importance of temperature and time controls; monitoring run-off from the mash tun for turbidity and specific gravity Hop variety: varieties of hops available (including brief histories and geographical location); characteristic properties of each variety; hop additions to brews (biochemistry of action); hop quality (appearance, feel and aroma) Hop biochemistry: the ratio of and -acids; oxidative conversions to humulones and hulupones; the effect of seed content on hop property and the principle contributors to aroma The copper: inactivation of enzymes; precipitation of proteins, polyphenols and some lipids; production of hop-derived flavours and aromas; sterilisation of the wort; further precipitation of calcium phosphate [Ca 3 (PO 4 ) 2 ] and its effect on ph; the distillation of volatile materials; water evaporation and subsequent wort concentration; enhancement of colour (caramelization, melanoidin formation, oxidation of tannins); reduction of surface tension Practical control: timescales involved in boiling and the stage points of hop introduction 3 Understand yeast physiology and microbiology Yeast physiology: Saccharomyces cerevisiae, Saccaromyces carlsbergensis, Saccaromyces uvarum, plus a selection of yeast strains and their properties; differences between topfermenting and bottom-fermenting strains; the role of recombinant DNA technology in future yeast research; economic role Yeast chemistry: yeast metabolism of macronutrients and the effect of these metabolites on the fermentation product; yeast metabolism of micronutrients and their effect on product quality; the role of exoenzymes; cell-permeability and physiological state; the importance of aeration to the fermentation process 134 BH027242 Edexcel BTEC Levels 4 and 5 Higher Nationals specification in Hospitality Management
4 Be able to identify fermentation and associated quality control systems Physical control systems: parameters instrumental in determining pitching rate; effect that fluctuation of temperature control will have on yeast physiology and end-product quality; the relationships between hydrometer readings, temperature, specific and original gravities; determining when a fermentation has run its course (end-point determinants); remedial measures to correct fermentation deviance Physiology of human sensory perception: biology of human senses Beer flavour influences: key contributing agents to beer flavour ie yeast (pitching rate, viability/vitality, strain purity/contamination), wort composition (dissolved O 2 concentration, OG, temperature, adjuncts and trub), fermentation vessel (size and geometry) Beer flavour biochemistry: specific beer flavourings such as CO 2, ethanol, glycerol, fusel oils, esters, organic acids, aldehydes, ketones, S 2 -compounds Industrial quality control: the industry practices of product evaluation; blind tasting philosophy; factors affecting the flavours of regional beer styles and types 135
Learning outcomes and assessment criteria Learning outcomes On successful completion of this unit a learner will: LO1 Understand fermentation systems Assessment criteria for pass The learner can: 1.1 discuss microbial range and form 1.2 evaluate the basic biological concepts of fermentation design 1.3 discuss the principal steps of the brewing process LO2 Understand the biochemistry of malting, mashing and conversions in the copper 2.1 discuss the role of barley in the malting process, highlighting the biochemical changes in the malting and mashing process 2.2 justify the practical controls and monitoring systems needed to ensure uniformity of clarified wort run-off 2.3 discuss the variety of hops available 2.4 discuss the biochemical conversions that take place during the boiling and hopping process 2.5 evaluate the practical systems used to maximise flavour and colour profiles and ensure uniformity of the end product LO3 Understand yeast physiology and microbiology 3.1 analyse the physiological and economic role played by yeasts in fermentation systems 3.2 discuss the biochemical conversions affected by yeasts during fermentation 3.3 discuss how these conversions can be controlled by environmental adjustment 3.4 assess the present and suggest future roles played by industry in the development of more active fermentation strains LO4 Be able to identify fermentation and associated quality control systems 4.1 apply the main concepts of regulatory control of a fermentation 4.2 create relevant data sources to identify SG and predict a brew s final OG 4.3 analyse the contributory factors that determine beer flavour 4.4 plan and carry out sensory and quality analysis of different beers to account for regional characteristics of similar brews in the industry 136 BH027242 Edexcel BTEC Levels 4 and 5 Higher Nationals specification in Hospitality Management
Guidance Links This unit can be linked with the following units within the qualification: Unit 16: Sales Development and Merchandising Unit 22: Cellar and Bar Operations Management Unit 23: Law for Licensed Premises. This unit also links to the following Management NVQ unit: A2: Manage your own resources and professional development. Essential requirements Learners must have access to laboratory facilities, food sensory facilities (for flavour evaluations and blind tastings) and the use of a micro-brewery facility. Site visits and guest speakers from industry will enhance delivery. Employer engagement and vocational contexts A visit to a local brewery or micro-brewery will substantially enhance the delivery of this unit. 137