BISCUIT MANUFACTURE

BISCUIT MANUFACT·URE

fundamentals of in-line production

by

PETER R. WHITELEY DIP. F.E., F.lnst. B.B.

Head of the Department of Baking. Rush Green Technical College.

Rmriford. Essex

APPLIED SCIENCE PUBLISHERS LTD LONDON

APPLIED SCIENCE PUBLISHERS LTD RIPPLE ROAD, BARKING, ESSEX, ENGLAND

ISBN: 0-444-20072-X

LIBRARY OF CONGRESS CATALOG CARD NUMBER 70-122961 WITH 121 ILLUSTRATIONS AND 5 TABLES

Cl 1971 ELSEVIER PUBLISHING COMPANY LTD

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publishers, Applied

Science Publishers Ltd, Ripple Road, Barking, Essex, England

Author's preface

THE intention of this book is to provide a guide for potential management and supervisors and for those who wish to understand the fundamental principles of biscuit manufacture. It does not set out to be a learned treatise. The purpose of the book is to simplify and explain processes and materials so that the 'mystique'is replaced by logic. Once the mystique is removed the biscuit maker is one step closer to anticipating and solving problems.

In attempting to cover this subject within one concise volume, it is difficult to avoid over-simplification or generalisation, and apologies must be offered in advance where these occur. To wallow in the fine details of specialisation is to defeat the object of the book, and less would be achieved if the issues were confused. The reader's attention is drawn to the interpretation of formulae (recipes). Raw materials, equipment, methods, processes, and conditions vary considerably; the formulae are intended as blue prints from which, with a knowledge of the materials and aims of the processes, and by trial and error, a biscuit can be produced bearing some semblance to the original. All formulae should be interpreted in conjunction with the 'Guide to using formulae' at the beginning of Chapter 12.

As the biscuit industry advances towards complete automation, plant and equipment become more advanced and sophisticated. Training of a very high standard is necessary to use sophisticated machinery efficiently, and where skills of this exacting degree are not available, then the simpler, less advanced equip­ment, should be used. It is with this in mind that processes have been dealt with in such a way that they can be carried out by hand or through varying degrees of mechanisation.

Similarly, the legislation regarding foods becomes so involved and changes so frequently that it is impossible to review for inclusion in a book of this nature. It is essential to be aware that there is legislation pertaining

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vi AUTHOR'S PREFACE

to practically every aspect of biscuit making and marketing, and as the legislation differs from country to country, further confusion arises. All governments issue pamphlets about their laws, and the appropriate Ministry or information office (in the United Kingdom, Her Majesty's Stationery Office) or legation should be approached for the current regulations.

Upminster, 1970 PETER R. WHITELEY

Acknowledgements

AN expression of thanks and gratitude is due to all those who helped with advice, information and photographs to make this book possible, including:

Baker Perkins Ltd, Peterborough British Cellophane Ltd, Twickenham Co-operative Wholesale Society Ltd, Biscuit Factory,

Harlow Walter Denis Contacts Co., Ltd, Blackpool Flour Milling and Baking Research Association,

Chorleywood J. Alan Goddard Ltd (Hecrona), Croydon J. W. Greer Co., Ltd, Bromley Kek Ltd., Macclesfield A. M. Lock & Co. Ltd, Oldham Machinery Continental Packaging Ltd (Aucouturier),

Rochester Morton Machine Co. Ltd, Wi shaw E. T. Oakes, Ltd, Macclesfield Radyne Ltd, Wokingham Rank Precision Industries Ltd, Brentford Rose Forgrove Ltd, Leeds SIG Wrapping Machines Ltd, Croydon Simon-Vicars Ltd, Newton-Ie-Willows .Spooner Food Machinery Engineering Co., Ltd, Ilkley My greatest appreciation is due to my wife, whose

untiring efforts of encouragement and help spurred me on at all times.

Upminster, 1970 PETER R. WHITELEY

vii.

Contents

AUTHOR'S PREFACE

ACKNOWLEDGEMENTS

LIST OF FIGURES IN THE TEXT

LIST OF TABLES

LI S T 0 F P L ATE S

PART I RAW MATERIALS

1 Flour and cereal products 2 Fats and oils 3 Sweetening agents 4 Aerating agents 5 Dairy products 6 Fruits and nuts 7 Setting materials 8 Chocolate and cocoa products 9 Flavouring materials

10 Colouring materials

PAR T II CLASSIFICATION AND METHODS

11 Classification of biscuit types and methods of

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xi

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1

22 34 42 50 59 69 73 81 94

production 103

PAR T III FORMULAE-QUALITY CONTROL AND DEVELOPMENT

12 Basic ingredient proportions of biscuit doughs 1 27 13 Basic ingredient proportions of wafers, marsh-

mallows, creams, and fillings 148

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x CONTENTS

14 Quality control 161 15 Re-use and disposal of unsatisfactory products 189 16 Development 193

PART IV PLANT AND EQUIPMENT

17 Raw materials storage and handling 201 18 Mixing room equipment 209 19 Machine room equipment 219 20 Ovens and baking 230 21 Wafers and second process equipment 241 22 Ancillary equipment and automation 250 23 Packaging of biscuits 258

PART V GENERAL CONSIDERATIONS

24 Factory layout and hygiene 269

BIBLIOGRAPHY 289

INDEX 290

List of figures in the text

1. Longitudinal section of a wheat grain 4 2. The pH scale 47 3. Sketch of a yeast cell 106 4. Yeast reproducing by budding 107 5. Colony of yeast cells 1 08 6. Diagram showing enzymic activity during

fennentation 111 7. Structure of a farinogram 163 8a. Farinogram: Manitoba flour 163 8b. Farinogram: strong English flour 164 8e. Farinogram: soft English flour 164 9a. Extensogram: Manitoba flour 166 9b. Extensogram: strong English flour 167 ge. Extensogram: soft English flour 167

10. Typical alveograms: (a) Manitoba flour; (b) strong English flour; (c) soft English flour 168

11. Typical graphs of extenso meter: (a) Manitoba flour; (b) strong English flour; (e) soft English flour 170

12. Line drawing of Simon-Vicars vertically integrated dough feeding, gauging and laminating unit 221

13. Examples of wire band patterns (Baker Perkins) 231

14. Air blast gas burners for direct fired oven (Baker Perkins) 235

15. Diagrams illustrating the principle of forced air convection baking used in a Spooner oven section 236

16. Line drawing of a Walden refrigerated air blast cooling tunnel 248

17. Diagrams illustrating how metals affect the electromagnetic field of an electronic metal detector 254

xi

List of tables 1. Structural composition of wheat 3 2. Typical analyses of flour samples 9 3. Typical analyses of milk and milk products 53 4. Table converting ingredient percentages to

pounds when based on flour weight of 280 Ib (i.e. one sack) and vice versa 128/129

5. Examples of texture meter readings obtained on retail samples of various types of biscuits 181

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List of Plates

(between pages 140 and 141) 1 a. Shortcake fingers 1 b. Round shortcake biscuits 2a. Shortcake biscuits: 'Royal Duchess' 2b. Lincoln (Lincoln Creams) 3a. Nice 3b. Finger creams 4a. Custard creams 4b. Bourbon creams 5a. Digestive (Sweetmeal) 5b. Currant biscuits 6a. Gingernu ts 6b. Half-coated (chocolate) sweet biscuits 7a. Coconut cookies (wire-cut) 7b. Cookies with chocolate, nuts and currants

included 8. Cream crackers 9a. Savoury crackers 9b. Creamed puff shells

lOa. Rich Tea biscuits lOb. Morning Tea biscuits 11 a. Marie biscuits 11 b. Finger-shaped, semi-sweet, hard dough

biscuits l2a. Garibaldi biscuits 12b. Morning tea biscuit showing hair-line

fracture known as 'checking' 13a. Coconut mallows 13b. Chocolate teacakes 14a. Jam rings 14b. Fig bars 15a. Cream filled wafers 1Sb. Bag-type pack.of coconut cookies 16a. Tray-type pack for mallows using a

preformed liner 16b. Tray-type pack for assorted biscuits using

a preformed liner (between pages 204 and 205)

17a. Brabender Farinograph

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xiv UST OF PLATES

17b. Brabender Extensograph 18a. Chopin Alveograph 18b. Simon Research Testing Unit 19a. Baker Perkins Texture Meter 19b. Baker Perkins Texture Meter showing

interior 20a. Douglas bulk fat storage vessels 20b. Douglas fat processing equipment with

mixing tanks on the right and the emulsifier­cooler on the left

21a. Douglas silos for storage of plasticised blended fats

21 b. Control room for bulk handling of ingredients

22a. Syrup blending tanks 22b. Morton HD 120 three-speed vertical mixer

of the planetary type 23. Simon-Vicars two-spindle vertical mixers 24a Morton Duplex 4V2 horizontal 'Z' blade

mixer 24b. Morton Gridlap GL 70 horizontal mixer

with control console 25a. Simon-Vicars high-speed mixer showing

interior 25b. Simon-Vicars high-speed mixer ejecting

biscuit dough directly into a floor mounted hopper

26a. The Oakes continuous mixer/modifier for bread and biscuit doughs

26b. Mixing rotor shaft of the Oakes continuous mixer/modifier

27a. The Oakes continuous automatic mixer for batters, marshmallow and fluid mixings

27b. Stator and rotor of mixing head of the Oakes continuous automatic mixer

28a. Morton 100 two-speed air pressure whisk 28b. Simon-Vicars floor mounted tub discharger 29a. Simon-Vicars tub elevator and discharge

unit to dough feeder

UST OF PLATES

29b. Simon-Vicars dough feed to sheeter showing scrap return

30a. Morton heavy duty reversing dough brake 30b. Simon-Vicars right-angle laminator 31. Hecrona vertical laminator 32. Simon-Vicars, cutting machine showing

dough feed, pre-sheeter, three pairs of precision gauge rolls and cutting machine cross head

33. Baker Perkins rotary cutting unit showing the pressure roller situated beneath the impression and cutting rollers

34a. Simon-Vicars rotary cutting unit in use with the guards removed

34b. Simon-Vicars fig bar extrusion unit situated directly above the oven band

35. Baker Perkins 88 BT rotary moulder with dough feed

36. Baker Perkins 88 BT rotary moulder with hopper opened showing the moulding roller and the grooved forcing roller

37. Baker Perkins Turboradiant oven with direct-fired boost on the first section

38a. Oil-fired heat sources for one section of a Baker Perkins Turboradiant oven

38b. Tower-type tensioning for oven band (Simon-Vicars)

39. Spooner forced air convection oven with wire band

40. Oven control panel for a Simon-Vicars gas-fired oven (in the background can be seen a radial reverse turn carrying the biscuits to an overhead cooling conveyor)

41. Radyne OCD 30 I electronic baking unit 42. Simon-Vicars Mark n wafer oven 43a. Simon-Vicars wafer sandwich building

machine with creamer in the background 43b. Simon-Vicars wafer saw 44. A battery of Simon-Vicars quality creamers

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xvi LIST OF PLATES

being fed directly from the cooling conveyor of the oven

45. Oakes oven pacer depositor producing marshmallow teacakes

46a. Walden automatic chocolate kettle 46b. Walden continuous trickle feed and

tempering machine 47a. Goddard automatic chocolate tempering

machine 47b. The Walden Supreme Mark 7 automatic

enrober 48. Baker-Sollich 76CQ enrober, a sophisticated

piece of equipment capable of control by computer

(between pages 236 and 237) 49a. Walden refrigerated air blast cooling tunnel 49b. Peck Mix for biscuit crumbing and raw

materials sieving 50. Kek Ltd. laboratory-size grinding mill

showing the discs and arrangement of the pegs

51a. Simon-Vicars Mark III oil spray unit with cover removed to show interior

51 b. Close up of the Baker Perkins oil spray unit showing the oil dispersers above and below the wire band

52. Greer spiral conveying system 53a. A Lock electronic metal detecting unit

monitoring fully coated wafer sandwiches 53b. An example of automatic control by Baker

Perkins Developments Ltd. (the instrument in the top centre of the photograph, by means of sensitive feelers, keeps the biscuit rows and the stacker guides in constant alignment)

54. Aucouturier wrapping machine, fed direct from the cooling conveyor, for round biscuits

LIST OF PLATES

55. Aucouturier wrapping machine for round packets with end seals

56. Aucouturier wrapping machine hand fed for ,square biscuits in piles using corrugated grease-proof paper and a heat-seal overwrap (mode of wrapping is also illustrated)

57. Rose F orgrove wrapping machine for pillow­type packages

58. 'Sendform' thermoforming machine for producing moulded plastic packing trays

59. SIG roll wrapping machine with automatic feeder

60. Close up of a SIG automatic loader (type ZH)

61. SIG automatic wrapping machine for fin­sealed packets with automatic feeder

62. SIG automatic wafer wrapping machine 63. Jones-Rose constant motion cartoning

machine 64. Rose Forgrove bag forming and filling

machine for tumble packs

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