The principles and practice of brewing

Front matter

THE

PRINCIPLES AND PRACTICE

OF

Preface To The First Edition

Among the achievements of the latter half of the present century, few have been fraught with more beneficial consequences than the practical application of the deductions of science to manufacturing operations. Nearly every important industry has passed from the empirical to the scientific stage. This revolution has not been effected at a leap, but has been of relatively slow growth. Much prejudice had to be overcome, and for a long time the intervention of science was regarded with considerable mistrust. Perhaps in no other industry was this the case more than in that of brewing. Now all this is changed ; the benefits which science is able to confer are generally recognised and appreciated, and where science was formerly repulsed, she is now welcomed with opened arms. That this is true with regard to the fermentation industries, is shown by the number of Institutions which have arisen in different parts of the world, during the last ten years, with the object of investigating the laws which govern the processes and operations carried on in malting, brewing, distilling, &c. In our own country, which has been one of the most backward in this respect, we have seen the founding of the Institute of Brewing and other kindred Institutions, which, together with their conjoint Journal, pay considerable attention to the scientific aspect of brewing.

During this short period an enormous amount of experimental investigation has taken place, the records of which are scattered over a vast amount of literature. It is the object of the present work to bring together, within the limits of a volume of a handy size, the salient points of this mass of literature, and to present, as it were, a bird’s eye view of the science and art of Brewing.

The two fundamental principles on which so much depends, viz., the action of diastase on starch, and the alcoholic fermentation caused by yeast, have been treated at considerable length, and as far as possible in historic sequence, so as to present these subjects to the reader in the most interesting form. In ^he Chemical portion of the book an attempt has been made to classify the substances used by brewers, and those appertaining to the science of Brewing, in a systematic form consonant with the arrangement generally adopted in modern works on organic chemistry. Chapters on the Physics of Brewing, such as heat and density, are also included. Considerable space has been allotted to a description of Elementary Biology, a subject of great importance

Vlll

PREFACE to the brewer, hut one which has been strangely neglected in most works on Brewing. The general methods of bacteriological research are also given, and a chapter is devoted to instructions for the use of the microscope, without the aid of which instrument bacteriology and the culture of pure yeast would be an impossibility. The interpretation of the results of the analysis of the materials used in brewing has been given, but the analytical methods of testing them have been omitted, as they would have made the book too voluminous, and constitute in themselves a subject sufficiently large to form a separate treatise.

In the practical portion of the work, the general methods employed in Malting and Brewing are given, but it is evidently impossible to include all the minor details, since these differ in almost every brewery, and can only be learned by actual experience in the brewery itself. The author trusts that the work will be found not only useful to those who are commencing a brewing career, and for whom it is primarily intended, but also to older, practical men who may be desirous of increasing their knowledge of the scientific side of brewing.

With these objects in view, he has attempted to present each subject in as lucid and intelligible a manner as possible, often, it is to be feared, at the sacrifice of literary elegance. Numerous references are given throughout the work solely for the benefit of those who wish to enlarge their knowledge of any particular subject ; in the great majority of cases these have been verified from the originals, and the remainder have invariably been taken from reliable sources.

The author would here express his indebtedness to many friends for much kind assistance in the compilation of the work, particularly to Mr. John Marriott and Mr. Harris S. Beaman, who have revised, respectively, the sections on Practical Malting and Practical Brewing ; also to Mr. A. Ashe for kindly looking over the microscopical portion, and to Mr. Arthur B. Ling (Editor of the Journal of the Federated Institutes of Brewing), and Mr. Charles A. Mitchell for assistance in correcting the proofs. A few of the illustrations in the bacteriological portion are from blocks lent by Mr. C. Gerhardt, of the Chemical Instrument Repository, Bonn, and some of those of brewery utensils are supplied by Messrs. Llewelyn & James of Bristol.

WALTER J. SYKES, M.D.

Ceoydon, August 1897.

Preface To The Third Edition

The Second (Revised) Edition of this book was published in December 1902, and received the same appreciative recognition as had been accorded to the original work. The steady sale quickly made it necessary to prepare for yet another edition, but Dr. Sykes, owing to a serious accident which he had met with in the summer of 1902, felt unequal to the task, and he accordingly sought my co-operation. The revision was completed and the present edition was practically through the press in December last when, to the profound regret of all, Dr. Sykes died.

Following the original object, the endeavour has been made, in bringing the work up to date, to add to the text a succinct but accurate account of researches on the subject which have been made during the last few years. It is believed that no important researches have been omitted.

Large additions have obviously been necessary notably in connection with stereochemistry, the chemistry of the carbohydrates and the enzymes, and more particularly in regard to the action of diastase on starch. The section dealing with hops has been considerably enlarged especially from the chemical point of view. Under vegetable biology and fermentation will be found numerous emendations and additions, and the chapters on barley, malting and brewing have been considerably extended. In order to include an account of certain researches published during the latter part of 1906 and the commencement of the present year, it has been found necessary to add an Appendix.

I have to express my indebtedness to the Council of the Institute of Brewing, the Editor of the Brewers' Journal , Messrs. R. J. Hanbury k Co., Messrs. S. H. Johnson k Co., and Messrs. Schmidt and Haensch for the use of blocks. I also desire to thank my assistant, Mr. T. Rendle, for help in connection with reading the proof-sheets.

ARTHUR R. LING.

The Laboratories,

74 Great Tower Street,

London, E.C.

Chapter I Physical Principles Involved In The Process Of Brewing

Heat

PAGE

Specific Heat

PAGE

Definition ....

Latent Heat ....

Conduction ....

Evaporation ....

• 13

Convection ....

Density and Specific Gravity .

. 14

Radiation ....

Density

. 14

Expansion ....

Specific Gravity

• 15

The Thermometer .

Hydrometers ....

• 17

Heat Unit ....

Saccharometers

. 21

Chapter II Chemistry, With Special Reference To The Materials Used In Brewing

The Elements 23

Combining Proportions ... 23

Molecules ...... 26

Chemistry of the Carbon Compounds 27

The Paraffins ..... 29

The Alcohols . . . . *31

The Aldehydes . . . . *31

The Aldoses . . . . .32

The Ketones 32

The Ketoces 33

The Acetic Acid Series 33

The Compound Ethers . . . 35

The Amides 36

Phenylhydrazine . . 37

Hydrazones 37

Osazones 38

Osones 39

Optical Stereoisomerides ... 40

Asymmetric Carbon Atom . . 43

Constitution of the Sugar Group . 46

Formation of Sugar in Living Plants 49

Disaccharides and Trisaccharides . 50

Sugar Estimation . . . . 53

Cupric Reducing Power ? , , 56

Solution Factor ....

Molecular Weight ....

ThePolarimeter and Specific Rotatory Power ....

Cellulose .

Starch .....

Behaviour of Starch with Iodine Gelatinisation of Starch .

Constitution of the Starch Molecule Soluble Starch ....

Amylodextrins ....

Maltose .....

Glucose .....

Fructose or Lsevulose Cane Sugar

Invert Sugar ....

Raffinose

a and jS Amylan

Furfural ...

Pectin

Fatty Constituents of Barley .

The Prote'ids or Albuminoids .

The Prote'ids of Barley .

The Prote'ids of Maize ,

5*

94 96 96

CONTENTS xii

PAGE

The Prote'ids of Malt . . .106

The Amides . . . . .108

Asparagine . . . . .108

Glutamine, &c. . . . .109

The Enzymes . . . . .110

The Diastases . . . .118

The Enzymes of Yeast . . -125

The Chemical Composition of Yeast 127 Action of Diastase on Starch . . 135

Investigations of O’Sullivan . 139

Musculus and Gruber . . . 144

Brown and Heron . . . . 145

Brown and Morris . . . .154

Maltodextrin 158

Molecular Weight of Starch . .160

Brown and Morris’s Second Hypothesis 161 Isomaltose ..... 162

Investigations on Isomaltose by Ling

and Baker 169

Brown and Morris . . . -171

Ost 172

Metamaltose 174

Achroodextrin III. . . . 175

PAGE

Ling and Baker’s further Investigations

Maltodextrin-a and -/3 Researches of Brown and Millar Synienski’s Investigations Investigations of Ling and Davis Further Investigations of Ling Investigations of Effront and of

Ford

Coagulation of Starch Action of Enzymes on Prote'ids Proteolytic Enzymes of Malt .

Nitrogenous Constituents of Malt .

Hops

The Hop Plant ....

Physical Characteristics of Hops Drying and Sulphuring Hops Chemical Constituents of Hops Essential Oil .

Bitter Principles and Resins .

Tannins ......

Alkaloids of Hops ....

Diastase of Hops ....

Storage of Hops ....

175 175 175 1 77

185 185 189

195 197

207 207

Part II Chapter, III

General Description of the Microscope ....

. 209

Nose-piece ....

. 212

Stage ....

. 212

Diaphragms ....

. 212

Sub-stage ....

. 213

Objectives ....

. 213

Eye-pieces ....

. 216

Illuminating Apparatus

. 216

Choice of Microscope .

. 217

Micro-Chemical Reagents

. 219

Microscopical Manipulation

. 220

Examination of Yeast .

• 225

Hanging-Drop Method .

. 226

Examination of Bacteria

. 227

Microscopical Preparations .

. 230

Bacteriological Methods . . . 232

Sterilisation 232

Thermo-regulator .... 233

Sterilising Apparatus . . . 234

Culture Media .... 236

Cultivation Plate .... 237

Moist Chamber .... 238

Incubator 239

Colonies 240

Impression Preparations . . 240

Petri Dishes ..... 241

Bacteriological Examination of

Hansen’s Method .... 243

Wichmann’s Method . . . 246

Bacteriological Examination of Air 247

CHAPTER IY

The Living Cell

. 249

Fermentation and Putrefaction

. 269

Protococcus pluvialis

. 249

Bacterium termo

. 271

Osmosis

• 253

Butyric Acid Bacteria

. 272

The Yeast Plant

• 256

Bacillus viscosus

. 272

The Wild Yeasts

. 263

The Acetic Bacteria .

• 273

The Mycoderms

. 264

The Sarcinas ....

. 274

The Torulas

. 265

The Mould Fungi

• 275

The Bacteria

. 265

Mucor mucedo

• 275

CONTENTS xiii

Mucor racemosus .

Other Mucors

Simple Multicellular Organisms Penicillium glaucum Eurotium aspergillus glaucus Botrytis cinerea Aspergillus oryzse .

Chalara mycoderma Oidium lactis Oidium lupuli

PAGE

281 281 284 286 288

PAGE

Dematium pullulans . . . 290

Monilia Candida . . . . 29 r

Mould Fungi Dangerous on Brewing Premises .... 292

The Higher Plants .... 293

Germination of Barley . . . 294

Structure of Barleycorn . . 295

Modification of Endosperm . . 298

Fate of the Cell walls of the Endosperm 299

CHAPTER Y

Fermentation, Antiquity of . . 304

Views on, during the Period of

the Alchemists . . . 305

during the Period of Iatro- Chemistry .... 306

during the Age of Phlogiston . 308

during the Period of the Foundation of Modern Chemistry . 309

Views of Liebig on . . . 312

Views of Traube . . 315

The Physiological Theory of Fermentation . . . . .315

Doctrine of Spontaneous Evolution . 317

Pasteur on Spontaneous Evolution 319 Tyndall’s Experiments . . . 322

Sterilisation of Organic Liquids . 323

Competition amongst Micro-Organisms ...... 326

Transformation of Organisms . . 326

Methods of obtaining a Pure Culture 327 Distribution of Atmospheric Germs . 328

Miquel’s Experiments on . . 332

Koch’s and other Methods of Air Investigation .... 332

Hansen’s Investigations on the Air

of Breweries .... 335

Pasteur’s Experiments on Fermentation 336

Mould Fungi as Ferments . . 339

Pasteur’s Experiments on Yeast . 339

Growth with and without Air . . 340

Pasteur’s Theory of Fermentation . 344

Meyer’s Theory . .... 347

Brefeld’s 348

Schiitzenberger’s .... 349

Nageli’s Moleculo-Physical Theory 351 Hoppe-Seyler’s Theory . . . 354

Buchner’s Researches . . . 355

Adrian Brown’s Experiments on Fermentation 361

Investigations of Hansen . . . 368

Pure Cultures from a Single Cell . 370

Varieties of Yeast . . . 371

Hansen’s Six Species and Varieties . 372

Introduction of Pure Yeast Cultures

into the Brewery . . . 374

Hansen’s and other Pure Yeast Cultivation Apparatus . . . 380

Hansen’s System and Top-Fermentation Brewing .... 386

Differences in the Action of the

various Yeasts .... 389

Saccharomyces thermantitonum . 391

Energy of Fermentation . . . 394

Part III Chapter VI

Water, Chemical Composition of . 396

Occurrence 396

Rain, Well, and Spring . . . 398

Statement of Results of Analysis

Hardness 401

Waters Suitable for the Production

of Different Classes of Ale . 403

Artificial Treatment of Waters . . 405

Kainit 406

Influence of Boiling .... 410

Organic Constitution . . .410

Effect of Filtration . . . .411

Methods of Water Analysis . .412

Microscopic Examination of Water

Sediments .... 419

XIV