Classification by enrichment of the formulation

All biscuits, cookies and crackers have flour as a major ingredient. There is usually some fat and sugar in their formulation and as the ratios of fat and sugar to flour are increased, both the method of manufacture and the eating quality of the baked product changes.

The following charts show how the ratios of sugar and fat relative to flour are related in the formulation of "biscuits" of different types:

Click charts to enlarge

Chart relating biscuit types by enrichment

Chart of all formulations relating fat and sugar to flour

For an understanding of the meaning of the names given for each area, please see the examples in the section on classification by method of processing below.

Another chart shows how when fat in the formulation is increased the level of water needed to make a dough decreases:

Chart of all formulations relating fat and dough water to flour

Further diagrams of enrichment of different types of biscuits are given in the section Examples of Biscuit Types.

Classification by method of processing

It is also possible to classify biscuit types by the methods in which they are made. The processing methods relate of course to the quality of the doughs. For example, doughs that have been mixed to cohesive and extendible consistency can be handled very differently from those that are crumbly.

Laminating, sheeting and cutting

An extensible dough (low in fat and sugar) is firstly sheeted and then folded or layered (laminated) many times before being turned and gauged to a thin sheet for the cutting of dough pieces for baking. The lamination, especially if a fatty material is introduced between the layers of dough, results in a more or less flaky baked product.

Many crackers are made in this way and if the amount of fat between the layers is large, puff biscuits are the result.

Sheeting and cutting

This is a very large group of biscuits. Mostly the doughs are low or very low in fat and sugar and are extensible, but it is possible to sheet non-extensible, short doughs that have much higher levels of fat and sugar. Mostly the short doughs are now processed with a rotary moulder (see later).

This group includes a number of crackers and all the semisweet types.

The eating textures are crisp and hard although in some cracker types, where the dough has been modified with proteinase enzyme, the eating is crisp and delicate.

In all cases, the dough which surrounds the cut pieces ("scrap dough") and is lifted away before the pieces pass into the oven, is returned to the sheeter and incorporated with fresh dough.

Rotary Moulding

This is the largest group of biscuits (cookies). A short, and more or less crumbly, dough, rich in fat and sugar, is pressed into mould cavities in a metal roller and these pieces are extracted and passed into the oven for baking. There is no scrap dough that has to be recycled.

Extrusion

A soft short dough is pressed through holes (dies). The extrusions may be cut immediately with a reciprocating wire frame, to allow pieces to fall ready for baking (this process is called wire cutting), or be allowed to form ropes which are cut into length either before or after baking.

It is possible also to co-extrude two (or three) doughs one within the other. The central material may be a fruit paste or jam. Usually the co-extrusions pass as ropes and are cut by guillotine before or after baking. In order to make dough pieces where the inner filling is completely contained within the outer dough, there are special co-extruders that cut the extruded dough by a process called "encrusting".

Depositing

A very soft or pourable dough (or batter) is extruded through dies and deposited directly onto the baking band. Typically the depositing machine moves in synchronisation with the baking band while the deposit is being extruded, then rises and moves back as the extrusion is stopped. In addition, the dies may rotate to make the deposits swirls or twists.

Wafers

Wafers offer a unique textural eating experience. The crispness and lightness blend admirably with soft cream or chocolate.

Wafers are thin sheets which are baked from a very fluid batter between hot plates. The gap between the plates determines the thickness of the wafer.

A special type of wafer are the rolls where the batter is baked on a large heated drum and the baked strip is rolled as it is taken from the drum. The rolls may be filled with chocolate.

Almost all wafers are produced as large sheets which are then sandwiched with cream or caramel toffee.

Secondary processing

Sandwiching with cream

A deposit of fat/sugar cream is placed on a thin biscuit and then a second biscuit is placed on top and pressed down. The cream is then cooled and it sets firm and adheres the two shells together.

Cream sandwiched biscuits are very popular as the cream affords an ideal means of introducing flavours that would not be possible from baked products. The cream may be either sweet or savoury. In the case of savoury (salty flavours) the cream is a mixture of fat and a non sweet material like milk powder or milled biscuit crumb.

Chocolate coating (enrobing)

Chocolate and biscuit (or creamed wafer pieces) are an excellent combination and are very popular. Liquid and tempered chocolate (prepared with the ideal content of crystals to ensure a hard glossy chocolate when it is cooled) is applied either on one side or all over the biscuit. If only one side is chocolate coated the biscuit is said to be half coated, if all over it is fully coated.

The coating may be either milk chocolate, plain chocolate, white chocolate or a chocolate flavoured coating.

Chocolate moulding

Biscuit or creamed wafer pieces are placed in moulds and the moulds are filled with chocolate. The chocolate is then cooled and knocked out of the mould. The moulded products look like chocolate bars.

Icing

The icing mixture is a suspension of very fine sugar crystals in water with a setting agent such as pectin, albumin or gelatine. The mixture is usually coloured and flavoured. Biscuits are coated (on only one side) with this mixture in the same way as chocolate is enrobed. The icing mixture is then dried in a warm tunnel and sets very hard.

In another form of icing the icing mixture is foamed into a formable state and this is deposited in peaks onto the surface of small biscuits which are then dried.

There are other specialist processing methods which are not widely used and are not covered here.