Brewing Yeast and Fermentation

Preface x

Acknowledgements xii

1 Beer and brewing 1

1.1 Introduction 1

1.2 Historical perspective 5

1.3 Current developments 15

1.4 Legislation 17

2 The brewing process 19

2.1 Overview 19

2.2 Beer types 19

2.3 The brewing process 29

2.4 Wort composition 46

2.5 High-gravity brewing 60

2.6 Glossary of brewing terms 63

3 The biochemistry of fermentation 69

3.1 Overview 69

3.2 Mass balance 71

3.3 Assimilation of wort nutrients 73

3.4 Carbohydrate dissimilation 81

3.5 Requirement for oxygen 97

3.6 Ethanol tolerance 108

3.7 Formation of flavour compounds 113

4 Brewing yeast 143

4.1 Morphology, cytology and cellular function 143

4.2 Taxonomy and differentiation 158

4.3 Genetics ± genome, cell cycle and modification 194

4.4 Cell wall and flocculation 237

5 Fermentation systems 260

5.1 General properties of fermentation vessels 260

5.2 Fermentation rooms 279

5.3 Traditional fermentation systems 284

5.4 Large-capacity fermenters 290

5.5 Accelerated batch fermentation 314

5.6 Continuous fermentation 316

5.7 Immobilised systems 346

5.8 Pilot scale fermentation systems 369

5.9 Laboratory fermentation systems 370

6 Fermentation management 377

6.1 Wort collection 377

6.2 Post-collection additions 402

6.3 Monitoring fermentation progress 404

6.4 Fermentation control 422

6.5 Fermentation management 445

6.6 Recovery of carbon dioxide 453

6.7 Yeast recovery 455

6.8 Fermenter run-down 461

6.9 Secondary fermentations 464

7 Yeast management 468

7.1 Laboratory yeast storage and supply 468

7.2 Yeast propagation 474

7.3 Yeast handling in the brewery 486

7.4 Assessing yeast condition 496

7.5 Surplus yeast 508

8 Microbiology 510

8.1 Product spoilage 510

8.2 Minimising the risk 537

8.3 Sampling and testing 565

References 586

Index 638