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The Biscuits

Biscuits broadly fall into four categories, distinguished by their recipes and process: crackers, hard sweet biscuits, short dough biscuits, cookies (including filled cookies). Each category and each product type requires a particular baking process: heat transfer method, temperature profile and humidity control.

Crackers 

A wide range of products characterised by crispy, open texture and savoury flavours. Crackers include soda and saltine crackers, cream crackers, snack crackers, water biscuits, puff biscuits, maltkist (sugar topped cracker), “TUC” type, “Ritz” type, vegetable crackers.

type of crackers

In general crackers may have some of the following features which influence the baking process:

  • doughs which are leavened and fermented with ingredients such as yeast, ammonia and sodium bicarbonate
  • doughs generally have a high water content (15 – 25%)
  • cracker doughs are laminated, (the dough sheet is made up from multiple thin layers)
  • cracker doughs spring or lift in the first part of the oven to achieve the open, flaky texture. This requires humidity and high heat input.
  • some crackers are baked in strips or complete sheets and broken into individual products after baking
  • some crackers require a colour contrast between dark blisters and a pale background colour
  • traditional English crackers such as cream crackers and water biscuits are normally baked on light wire-mesh bands
  • traditional American crackers, such as soda or saltine are baked on heavy mesh oven bands which are pre-heated to transfer heat rapidly by conduction into the dough pieces crackers are baked to low moisture contents (1.5% – 2.5%), which requires a high energy input 


Production machines for a Snack Cracker:

Mixing 
Horizontal 2 speed (30/60rpm) or variable speed mixer
75KW motor

Forming 
Vertical laminator
3 pairs of gauge rolls
Relaxation conveyor
Rotary cutter (single roll or two roll system)

Baking 
Direct gas Fired Oven
Z47 wire-mesh band
Pre-heat
Average oven burner rating 28KW/m2 
Baking temperatures: 220 / 220 / 220 /180 degrees C
Baking time: 5.0 minutes

Oil spray

Cooling 
Cooling to baking ratio 1.5 : 1

Hard sweet biscuits 

Examples of hard sweet biscuits are Marie, Petit Buerre, Rich Tea, Arrowroot, Gem, Morning Coffee. They are characterised by an even, attractive colour and texture and good volume. Doughs for hard sweet biscuits have the following features:

hard sweet biscuits

 

  • doughs have strong, developed gluten which gives an elastic dough, which often shrinks in the first stage of baking
  • doughs have low sugar and fat
  • doughs have water contents typically of around 12%
  • biscuits are normally baked on a wire-mesh band (except for Marie which is traditionally baked on a steel band)
  • humidity in the first part of the baking is important to achieve good volume and a smooth surface sheen
  • biscuits are baked to low moisture contents, around 1.5% – 3.0%


Production machines for hard sweet biscuits:

Mixing 
Horizontal 2 speed (30/60rpm) or variable speed mixer
75KW motor
Good temperature monitoring of the dough
Accurate temperature controller

Forming 
3 roll sheeter with good scrap incorporation (separate hopper and feed roll)
3 pairs of gauge rolls (final rolls 400mm diam.)
Relaxation conveyor
Rotary cutter (two roll system)

Baking 
Direct gas fired oven / convection oven
Steel band
Average oven burner rating required: 22KW/m2 
Baking temperatures: 200 / 220 / 220 /180 degrees C
Baking time: 5.0 – 6.5 minutes

Short doughs (moulded biscuits) 

This is another wide category with many designs. The doughs are short with higher fat and sugar contents than the crackers and hard sweet biscuits. This is the simplest category for the dough piece forming process (rotary moulding) and so these products are very widely produced, often in very high volumes. The list of typical products could be very extensive and contains many local or regional specialities:

Malted milk, Glucose, Lincoln, Digestive, Nice, Shortbread, Custard Cream from Britain, Italian frollini, Dutch speculaas, caramelised biscuits, German lebkuchen...

soft doughs - rotary moulded biscuits short doughs - rotary moulded biscuits

  • doughs have a low water content, but more fat and sugar than the hard biscuits
  • high humidity in the first part of the baking process to allow the biscuit structure to form
  • relatively slow baking at comparatively low temperatures 


Production machines for moulded short dough biscuits:

Mixing 
Horizontal 2 speed (30/60rpm) or variable speed mixer
75KW motor
Good temperature monitoring of the dough
Accurate temperature controller

Forming 
Rotary moulder
Moulding roll with plastic inserts
Adjustment for forcing roll gap
Radial adjustment of the knife position
Adjustment of the rubber covered pressure roll
Speed control for moulding roll and extraction web

Baking 
Direct gas fired oven / convection oven
Z 47 wire-mesh band
Average oven burner rating required: 20KW/m2 
Baking temperatures: 180 – 220 C
Baking time: 4.0 – 5.5 minutes

Cookies 

Chocolate chip cookies, butter cookies, two dough cookies, centre filled cookies, fig bars, fruit bars, extruded cookies, cookies with many types of inclusion such as nuts, raisins, coconut, chocolate chips...

cookies

  • very soft doughs which are deposited directly onto the oven band
  • high fat and sugar recipes
  • long baking times with relatively low baking temperatures
  • all products are baked on steel bands
  • high humidity is required in the first oven zones to allow the dough to spread on the oven band 


Production machines for cookies

Mixing: Removable bowl batch mixer

  • stainless steel construction
  • bowl lifts and seals
  • bowl with heavy duty casters
  • planetary mixing action
  • air pressure to control specific gravity
  • variable speed drive with inverter
  • detachable / interchangeable mixing tools to suit each type of dough, batter or cream


Forming: Wire-cut machine

  • stainless steel hopper
  • grooved feed rolls driven continuously
  • variable speed drive with inverter
  • adjustable gap between feed rolls
  • reciprocating wire mechanism
  • interchangeable die plates carrying die nozzles


Baking 
Direct gas fired oven / convection oven
Steel band
Average oven burner rating required: 22KW/m2

filled cookies
danish butter cookies

Filled cookies and Danish Butter cookies comprise both rotary moulded and deposited / wire cut cookies.

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