Biscuit Baking Technology: Processing and Engineering Manual

Biscuit Baking Technology
Introduction
Copyright
Contents
About the author
Iain Davidson, Director, Baker Pacific Ltd.
Baker Pacific Ltd.
Experience in the biscuit industry
Acknowledgements
1 The biscuits, cookies and crackers
1.1 The biscuits, cookies and crackers
1.2 Crackers
1.3 Soda crackers: process for sponge and dough
1.3.1 Description
1.3.2 Product specification
1.3.3 Formulation
1.3.4 Critical ingredients
1.3.5 Mixing and fermentation
1.3.6 Dough forming
1.3.7 Baking
1.3.8 Oil spray
1.3.9 Cracker breaking
1.4 Cream crackers: process for laminated crackers
1.4.1 Description
1.4.2 Product specification
1.4.3 Recipe
1.4.4 Dough mixing on a horizontal high-speed mixer
1.4.5 Preparation of the fat/flour for dusting
1.4.6 Lamination
1.4.7 Baking
1.5 Snack crackers
1.5.1 Process for snack crackers
1.5.2 Description
1.5.3 Product specification
1.5.4 Formulation
1.5.5 Critical ingredients
1.5.6 Mixing
1.5.7 Standing time
1.5.8 Forming
1.5.9 Baking
1.5.10 Baking band
1.6 Semi-sweet biscuits
1.6.1 Process for semi-sweet biscuits
1.6.2 Description
1.6.3 Product specification
1.6.4 Formulation
1.6.5 Critical ingredients
1.6.6 Mixing
1.6.7 Forming
1.6.8 Baking
1.6.9 Cooling
1.7 Process for Golden Maria or Dorada
1.7.1 Description
1.7.2 Product specification
1.7.3 Formulation
1.7.4 Mixing
1.7.5 Dough forming
1.7.6 Baking
1.8 Short doughs: rotary moulded biscuits
1.8.1 Process for moulded short dough biscuits
1.8.2 Description
1.8.3 Product specification
1.8.4 Formulation
1.8.5 Critical ingredients
1.8.6 Mixing
1.8.7 Standing time
1.8.8 Rotary moulding
1.8.9 Baking
1.8.10 Cooling
1.8.11 Process for ginger biscuits
1.8.12 Description
1.8.13 Product specification
1.8.14 Formulation
1.8.15 Process for ginger crunch biscuits
1.9 Cookies
1.10 Process for a chocolate chip cookie
1.10.1 Description
1.10.2 Product specification
1.10.3 Formulation
1.10.4 Mixing
1.10.5 Forming
1.10.6 Baking
1.10.7 Cooling
1.11 Sandwich biscuits
1.11.1 Description
1.11.2 Recipes for creams
1.11.3 Process for sandwich production
1.12 Long shelf life cakes, snack cakes
1.12.1 Process for Jaffa cakes
1.12.2 Product specification
1.12.3 Mixing
1.12.4 Baking
1.12.5 Cooling and jam depositing
1.12.6 Recipes
1.13 Summary
References
2 Baking process
2.1 From the dough piece to the biscuit
2.1.1 Biscuit structure
2.1.2 Moisture content
2.1.3 Colour
2.2 Ingredients
2.2.1 Wheat flour
2.2.2 Wheat flours: typical specifications
2.2.2.1 Wheat gluten
2.2.2.2 Starch
2.2.3 Sugar
2.2.4 Leavening agents
2.2.4.1 Yeast
2.2.4.2 Sodium bicarbonate (“soda”)
2.2.4.3 Ammonium bicarbonate (“vol”)
2.2.5 Fats
2.3 Baking process
2.3.1 Development of the biscuit structure and texture
2.3.2 Moisture removal
2.3.3 Colour
2.3.4 Summary
References
3 Baking profiles
3.1 Crackers
3.1.1 Structure
3.1.2 Moisture content
3.1.2.1 Latent heat of evaporation: 539kcal/kg
3.1.3 Colour
3.1.4 Oven specification
3.1.5 Baking profile
3.2 Snack crackers
3.2.1 Structure
3.2.2 Baking process
3.2.3 Moisture content
3.2.4 Colour
3.2.5 Baking times and temperatures
3.2.6 Baking profile
3.3 Semi-sweet biscuits
3.3.1 Structure
3.3.2 Moisture content
3.3.3 Colour
3.3.4 Oven specification
3.3.5 Baking profile
3.4 Short dough biscuits
3.4.1 Structure
3.4.2 Moisture content
3.4.3 Colour
3.4.4 Oven specification
3.4.5 Baking profile
3.5 Cookies
3.5.1 Structure
3.5.2 Moisture content
3.5.3 Colour
3.5.4 Oven specification
3.5.5 Baking profile
References
4 Biscuit design and output
4.1 Cutter and moulding roll layouts
4.2 Scrap and scrapless designs
4.3 Semi-sweet biscuits
4.4 Short dough biscuits and cookies
4.5 Docker pins
4.6 Oven band loadings
4.7 Oven size and output
4.7.1 Output calculation
4.8 Summary
Further reading
5 Heat transfer
5.1 Radiation
5.1.1 Wavelength
5.1.2 Radiant heat transfer
5.1.3 Distance
5.1.4 Effect of radiation on the dough pieces
5.1.5 Radio-frequency baking
5.1.6 Near-infrared baking
5.1.7 Microwave
5.2 Conduction
5.2.1 Baking with conduction
5.2.2 Oven insulation
5.3 Convection
5.3.1 Convection baking
5.4 Summary
5.4.1 Radiation
5.4.2 Conduction
5.4.3 Convection
Further reading
6 Oven designs
6.1 Heat transfer methods
6.1.1 Radiant heating
6.1.2 Conduction heat transfer
6.1.3 Convection baking
6.2 Radiant heating
6.2.1 Direct gas-fired ovens
6.2.2 Conversion to electrical heating
6.2.3 Summary
6.2.4 Electric ovens
6.2.5 Summary
6.2.6 Indirect radiant ovens
6.2.7 Summary
6.3 Turbulence systems
6.4 Conduction heat transfer
6.5 Convection baking
6.5.1 Direct convection ovens
6.5.2 Indirect convection ovens
6.5.3 Summary
6.5.4 ‘Re-circ’ ovens
6.5.5 Summary
6.6 Hybrid ovens
6.6.1 Direct gas-fired/indirect radiant ovens
6.6.2 Direct gas-fired/convection ovens
Further reading
7 Oven specifications
7.1 Specifications for ovens: crackers
7.1.1 Development of structure and texture
7.1.2 Reducing moisture content
7.1.3 Colour
7.1.4 Final moisture content
7.1.5 Recommended specification for a cracker oven
7.2 Recommended oven specification for light carrier products, for example crispbreads, rusks
7.3 Recommended oven specification for semi-sweet biscuits, for example Marie
7.4 Recommended oven specification for short dough biscuits
7.5 Specifications for ovens: soft dough cookies
7.6 Danish butter cookies
7.7 Modular oven design
7.8 Calculation of oven zone lengths
7.8.1 Example 1: Direct gas-fired oven for baking crackers (1.5×100m long)
7.8.1.1 Heat input
7.8.2 Example 2: Indirect radiant oven for baking a short dough biscuit, glucose type (1.25m×100m long)
7.8.2.1 Heat input
7.8.3 Example 3: Multipurpose oven 1.25m×91.0m
Additional information on sources
Biscuit oven manufacturers
Oven band manufacturers
Oven burner manufacturers
Heat flux technology
8 Oven construction: direct gas-fired ovens
8.1 Direct gas-fired baking chamber
8.1.1 Baking chamber construction
8.1.2 Conversion of gas-fired oven to electric
8.1.3 Materials
8.1.4 Dimensions
8.1.5 Expansion joints
8.1.6 Insulation
8.1.7 Oven return band covers
8.1.8 Explosion relief
8.1.9 Inspection doors
8.1.10 Cleanout doors
8.2 Extraction system
8.2.1 Fan specification
8.2.2 Extraction: oven end hood
8.3 Direct gas-fired oven: gas burner system
8.3.1 Gas train
8.3.2 Combustion air
8.3.3 Temperature control system
8.3.4 Flynn burners for direct gas-fired oven
8.3.5 Infrared metal fibre burners
8.3.6 Flynn infrared profile 7 distributor burner
8.4 Control panels
8.4.1 Main control panels
8.4.2 Control panel construction
Further reading
9 Oven construction: indirect radiant ovens
9.1 Indirect radiant baking chamber
9.1.1 Baking chamber construction and dimensions
9.1.2 Expansion joints
9.1.3 Heater module
9.1.4 Radiant tubes
9.1.5 Return ducts
9.1.6 Circulation fan
9.1.7 Extraction and turbulence
9.1.8 Heat exchanger flue (chimney)
9.1.9 Explosion relief
9.1.10 Insulation
9.1.11 Inspection doors
9.1.12 Cleanout doors
9.2 Indirect fired ovens: burners
9.2.1 Weishaupt burners
9.2.1.1 Technical description
9.2.1.2 Specification: Weishaupt burner WG30N/1-C ZM LN (for 1.25m wide indirect radiant oven)
9.2.2 Maxon burners
9.2.2.1 Specification for 1.2m wide indirect radiant oven
9.2.2.1.1 Maxon OVENPAK 515 gas/oil burner
9.2.2.1.2 Maxon gas pipe trains
9.2.2.1.3 Pilot gas train
9.2.2.1.4 Oil pipe train
9.2.2.1.5 Compressed air train
Further reading
10 Heat recovery system
10.1 Heat recovery system
10.1.1 Calculations of hot air flow to the HRS zone
Further reading
11 Oven construction: convection ovens
11.1 Direct and indirect convection systems
11.2 Baking chamber
11.2.1 Baking chamber construction
11.2.2 Convection plenums
11.2.3 Return air
11.2.4 Circulation fan
11.2.5 Heater module
Further reading
12 Oven construction: electric ovens
12.1 Electric oven construction
12.2 Electrical elements
12.3 Conversion of direct gas-fired oven to electrically heated oven
12.4 Oven efficiency
12.5 Ovens with hot air circulation
12.5.1 Indirect radiant oven
12.5.2 Convection ovens
12.6 Control systems
Further reading
13 Oven conveyor bands (belts)
13.1 Rolled wire-mesh bands (belts)
13.1.1 Z-type bands
13.1.2 Wire-mesh bands: skid bar supports
13.1.3 Wire-mesh bands: support rollers
13.1.4 Return band supports
13.1.5 Wire-mesh oven band cleaning
13.1.6 Wire-mesh oven band tracking
13.1.7 Joining wire-mesh bands
13.1.8 Dimensions of rolled wire-mesh belts
13.2 Compound balanced weave bands
13.2.1 Compound balanced weave band supports
13.2.2 Band tracking for compound balanced weave bands
13.2.3 Joining Ashworth bands
13.2.4 Dimensions of compound balanced weave bands
13.3 Steel bands
13.3.1 Steel band supports
13.3.2 Joining steel bands
13.3.3 Steel band cleaners
13.3.4 Steel band greasing
13.3.5 Steel band tracking
Further reading
14 Oven conveyor design
14.1 Oven conveyor
14.2 Feed end
14.2.1 Oven terminal drums
14.3 Delivery end
14.3.1 Delivery end drum
14.3.2 Oven drive
14.3.3 Sprag clutch
14.3.4 Uninterruptible power supply
14.3.5 Stripping conveyor
14.3.6 Oven end hood design
14.3.7 Calculation of oven band tension
14.3.8 Calculation of torque required for the conveyor drive
14.3.9 Calculation of electric motor power
Further reading
15 Process control systems
15.1 Temperature control
15.1.1 Direct gas-fired ovens
15.1.2 Indirect radiant ovens
15.1.3 Convection ovens
15.1.4 Electric ovens
15.1.5 Temperature monitoring and control
15.1.6 Temperature controllers
15.1.7 PID control
15.1.8 Top and bottom temperature control
15.2 Baking time
15.3 Humidity
15.4 Colour control
15.4.1 Direct gas-fired ovens
15.4.2 Indirect radiant ovens
15.4.3 Colour measurement
15.5 PLC control
15.5.1 Specification for a PLC control system
Further reading
16 Oven safety monitoring and alarm
16.1 Oven band safety systems
16.1.1 Oven band tracking
16.1.2 Detection of the oven band position
16.1.3 Oven band drive
16.1.4 Emergency stops
16.1.5 Emergency oven band drive
16.1.6 Oven band tension system
16.2 Oven burners and gas system
16.2.1 Gas trains
16.2.2 Gas system
16.2.3 Main gas solenoid valves
16.2.4 High-/low-pressure switch
16.2.5 Zero gas governor
16.2.6 Purge system
16.2.7 Over-temperature safety
16.3 Direct gas-fired ovens: manual control of top and bottom burners
16.3.1 Air system
16.3.2 Burner flame supervision
16.3.3 Gas/air mixture
16.4 Indirect-fired ovens: Weishaupt burners
16.4.1 Excess temperature
16.5 Extraction, combustion air and circulation fans
16.5.1 Damper controls
16.6 General safety equipment and instructions
16.6.1 Guards and safety devices
16.6.2 Operation safety precautions
16.6.3 Cleaning and maintenance safety precautions
16.6.4 Commissioning safety precautions
16.6.5 Running the equipment without safety systems
16.6.6 Protection of employees
16.6.7 Emergency shutdown
Further reading
17 Manufacture of biscuit ovens
17.1 Why build the oven locally?
17.2 Building baking ovens locally: the tasks and team
17.2.1 The team and experience required
17.3 Manufacturing drawings
17.4 Control and safety systems
17.5 Contractors
17.6 Purchasing
17.7 Shipping
17.8 Installation
17.9 Summary
Further reading
18 Oven operation: direct gas-fired oven
18.1 Starting the direct gas-fired oven: preparation
18.1.1 Baking programme
18.1.2 Burner pattern
18.1.3 Before starting the oven
18.2 Lighting the burners – direct gas-fired zone
18.3 Heating up/start of production
18.4 Shutting down the direct gas-fired oven
18.4.1 When temperature drops to 100°C
18.5 In the event of power failure
18.6 In an emergency
Further reading
19 Oven operation: indirect radiant oven
19.1 Preparation
19.1.1 Baking programme
19.1.2 Before starting the oven
19.2 Starting the oven
19.2.1 Controls and settings
19.2.2 Lighting the burners
19.2.3 Heating up/production
19.2.4 Damper controls
19.2.5 Zone heating controls
19.2.6 Extraction and turbulence dampers
19.3 Shutting down the indirect radiant oven
19.3.1 When temperature drops to 100°C
19.4 In the event of power failure
19.5 In an emergency
19.6 Control of the heat recovery system
Further reading
20 Oven efficiency
20.1 Energy use
20.2 Example of energy usage
20.2.1 Product and oven
20.2.2 Data from independent test results
20.2.3 Energy to bake the product
20.2.4 Heat loss from extraction from baking chambers
20.2.5 Heat loss from return band
20.2.6 Heat loss from the insulation and outer covers of the oven
20.2.7 Heat loss from oven delivery end
20.2.8 Heat loss from burner flues
20.2.9 From the calculations above, the energy consumption of the oven per hour
20.3 Comparison of oven efficiency for different oven types (based on actual installations)
20.4 Calculations for the energy required to bake biscuits
20.4.1 Rotary moulded biscuit
20.4.2 Semi-sweet biscuit
20.4.3 Cracker
References
21 Energy for biscuit baking
21.1 Combustion data: natural gas
21.1.1 Combustion process
21.1.2 Carbon dioxide emission from burning natural gas
21.2 The biscuit industry carbon footprint
21.2.1 Climate change and greenhouse gases
21.2.2 Energy usage for baking
21.2.3 Consumption of gas for baking
21.2.4 The carbon footprint
21.2.5 Energy sources for biscuit baking
21.3 Generating electricity from renewable energy sources
21.3.1 Power generation costs for renewable energy
21.3.2 Development of electricity generation from renewables
21.3.3 Future developments for biscuit baking
21.4 Solar energy
21.4.1 New biscuit bakeries
21.4.2 Solar energy for a new bakery
Further reading
22 Oven inspection and audit
22.1 Oven performance
22.1.1 Output
22.1.2 Product specification/compliance
22.1.3 Energy usage
22.2 Oven band
22.3 Baking chamber
22.4 Gas and oil trains
22.5 Gas burners
22.5.1 Burners: direct gas-fired ovens
22.5.2 Burners: indirect-fired ovens
22.6 Temperature and humidity control systems
22.6.1 Heat flux
22.6.2 Measurement of heat flux
22.6.3 Baking temperature and humidity
22.7 Controls and electrical panels
22.8 Reporting
Further reading
23 Oven maintenance
23.1 Preparation
23.2 New equipment
23.3 Routine maintenance
23.3.1 Safety devices
23.4 Mechanical components
23.4.1 Welded components
23.4.2 Driving chains and belts
23.4.3 Motors and drives
23.4.4 Steam lines and fittings
23.4.5 Air lines and fittings
23.4.6 Seal and gaskets
23.4.7 Bearings
23.4.8 Conveyor belts
23.4.9 Oven band tension
23.4.10 Pneumatic tension arrangement
23.4.11 Band pressure switch
23.4.12 Oven band tracking
23.4.13 Bearings for oven band support rollers
23.4.14 Explosion panels
23.4.15 Oven flues
23.4.16 Pulleys for fans
23.4.17 Fans
23.5 Electrical maintenance
23.5.1 General
23.5.2 Cleaning
23.5.3 Relays
23.5.4 Inspection schedule for relays
23.5.5 Temperature controllers
23.5.6 Connections and leads
23.5.7 Fuses
23.5.8 Earth leakage protection devices
23.5.9 Clutches and brakes
23.5.10 Transistor/solid-state devices
23.5.11 Limit switches
23.5.12 Proximity detectors (inductive or capacitive)
23.5.13 Plug-in timers
23.5.14 Battery safety
23.6 Maintenance schedule
23.6.1 Each day
23.6.2 Each week
23.6.2.1 Driving belts
23.6.2.2 Fan filters
23.6.2.3 Inspection and access doors
23.6.2.4 Oven lamps
23.6.2.5 Dampers
23.6.2.6 Emergency drive
23.6.2.7 Oven ignition
23.6.2.8 Oven band
23.6.3 Every 12 months
23.6.3.1 Burners and gas equipment
23.7 Oven cleaning
23.8 Standard lubrication
23.8.1 Ball/roller bearings with provision for lubrication
23.8.2 Sealed ball bearings
23.8.3 NSK-RHP self lube bearings
23.8.4 Recommended lubricants
23.8.5 Every 200 h
23.8.6 Every 2500 h
23.8.7 Every 5000 h
23.8.8 Each year
23.9 Maintenance log or record
23.10 Recommended spare parts
23.10.1 Gas system
23.10.2 Weishaupt burners
23.10.3 Maxon burners
23.10.4 Flynn burners
23.10.5 Electrical/temperature control parts
23.10.6 Mechanical parts
References
Appendix 1 Ingredients for biscuits: an introduction
1 Flour
1.1 Wheat flour
1.2 Corn flour
2 Sugars and syrups
2.1 Sucrose
2.2 Glucose syrup
2.3 Cane syrup 80%
2.4 Invert syrup 70%
2.5 Fructose syrup 80%
2.6 Malt extract 80%
3 Fats
3.1 Dough fat
3.2 Butter
3.3 Palm oil
3.4 Coconut oil
4 Dairy products
4.1 Whole egg powder
4.2 SMP, FCMP—skimmed milk powder, full cream milk powder
5 Leavening agents
5.1 Yeast (fresh)
5.2 Ammonium bicarbonate (“Vol”) (NH4)HCO3
5.3 Sodium bicarbonate (“Soda”) NaHCO3
5.4 ACP—acid calcium phosphate
5.5 SAPP or PURON—sodium acid pyrophosphate
6 Emulsifiers
6.1 Lecithin
6.2 GMS—Glycerol monostearate
7 Flavour enhancers
7.1 Salt
7.2 Monosodium glutamate (MSG) C5H8NO4Na
7.3 SSL—sodium stearoyl lactylate
8 Preservative
8.1 SMS—Sodium metabisulphite Na2S2O5
9 Enzymes
9.1 Proteolytic enzymes
Bibliography
Appendix 2 Specification of a multi-purpose oven 1.27×91.9m
1 Oven feed end
2 Direct gas fired zone 31.9m long with three heat control zones
3 Direct gas fired burners and gas equipment
3.1 Gas train
3.2 Air supply
3.3 Burner system
3.4 Automatic temperature control
4 Indirect radiant oven
4.1 Oven burners
4.2 Gas train
4.3 Automatic temperature control
4.4 Turbulence/convection system
4.5 Thermocouples and pressure gauges
5 Oven band
5.1 Oven band cleaner
6 Delivery end section
6.1 Oven end extraction hood
7 Control panels
8 Oven safety systems
8.1 Oven band
8.2 Ignition
8.3 Purge system
8.4 Over temperature
8.5 Power failure
9 Components and finishes
9.1 Electrical installation
9.2 Components
9.3 Finishes
Bibliography
Appendix 3 Oven manufacturers
1 China
1.1 Dongguang Furong Food Machinery Factory
1.2 Evergrowing Food Machinery Co. Ltd
1.3 Shanghai Kuihong Food Machinery
1.4 Sinobake, Guandong Shunde Huaji Industrial Co
1.5 Skywin Foodstuff Machinery Co. Ltd
1.6 Zhongshan Dingson Food Machinery Ltd
1.7 Zhuhai Hong Fu Mechanical Manufacturing Co. Ltd
2 EUROPE
2.1 Aasted ApS
2.2 Baker Perkins Ltd
2.3 Baker Perkins Inc
2.4 Bühler Group
2.5 GEA IMAFORNI INT'L S.p.A
2.6 Laser Srl
2.7 Pek Makina
2.8 Polin, Ing POLIN E C. SpA
2.9 Senius Equipment Aps
2.10 Spooner Vicars Bakery Systems
2.11 TMFCT – Bonnand Lornac
2.12 Werner & Pfleiderer
3 India
3.1 Bake-o-Nomic Corp
3.2 Besto Oven Industries
3.3 Esspee Engineers, Kolkata
3.4 New Era Machines
3.5 Ovenman Industries Private Ltd
4 Japan
4.1 Misuzu Koki Co Ltd
4.2 Naigai-Vicars
5 Korea
5.1 Dong Yang Food Machinery Co. Ltd
6 United States
6.1 Baker Perkins Inc
6.2 Reading Bakery Systems
Appendix 4 Oven band manufacturers
1 Agrati La Bridoire Sarl
2 Ark Engineers
3 Ashworth Bros. Inc
4 Audubon
5 Berndorf Band Gmbh
6 Bharat Wire Mesh Company
7 Cambridge Engineered Solutions
8 Consol Machinery (Canton) Co. Ltd
9 Durgesh Industries
10 Heights Wire Belt Factory
11 IPCO
12 Rexnord Inc
13 Shri Jai Maharani Industry
14 Steinhaus GmbH
15 Yangzhou Jiangdu Huada Metal Mesh Belt Factory
16 Yangzhou Jinrun Mesh Belt Manufacturing Co
Index