Biscuit manufactureThe principal ingredients used in the manufacture of biscuits are wheat flour, fat and sugar.
Water plays an important role in the biscuit making process but is largely removed during baking. Baked goods are normally decorated and ingredients like dried and wet fruit, cream, custard etc. are utilised.
There are two basic dough types: hard doughs, and short doughs. Whatever the dough type, the basic process steps involved in biscuit manufacture are dough mixing, formation of the dough pieces, baking, cooling and packaging. The methods used at each stage vary considerably depending on the product type. Raw materials are usually received in bulk and automatically metered into dough mixers but small ingredients such as salt and sodium bicarbonate may be weighed and added by hand. The ingredients are blended and, in the case of hard doughs, mixed to promote a gluten network in the dough. In the case of short doughs mixing is such that gluten development is deliberately limited. The formation of dough pieces varies depending on the biscuit type. Crackers and semi-sweet biscuits are cut from continuous sheets of rolled hard dough; crackers requiring considerable processing as they are built up in a series of thin layers.
Most short doughs are formed by rotary moulding, but soft doughs for cookies are usually wire cut. The biscuits are baked, usually in tunnel ovens. The times and temperatures used vary depending on the product. Ovens may be direct or indirect fired, gas or electric. The baked biscuits are cooled and packed or transferred for secondary processing (e.g. layering of cream fillings).
Crackers may be oil sprayed immediately after baking. Cooling is typically achieved by conveying the biscuits around the plant for a set time period.