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A biscuit is a hard and crunchy cookie.
A basic recipe for the pastry of a biscuit is: 100 kg flour, 30 kg sugar, 25 kg water, 20 kg fat, 1.5 kg salt, 0.5 kg sodium hydrogen carbonate, 0.5 kg ammonium hydrogen carbonate.
The flour that is used is “Zeeuwse” flour. This is a white flour with a low percentage of protein and a moderate protein quality. In this way the flour can create a gluten network while its gas containing capacity is low.
The fat that is used is a quite solid fat, which is called cake fat. The rising agents that are used, sodium hydrogen carbonate and ammonium hydrogen carbonate, make the cookie to rise in height as well as width.
Ammonium hydrogen carbonate may only be used in products in which the ammonium gas that is formed can escape. More attention will be paid to this later in the process.
In the first place water, the rising agent and salt are mixed. After that the flour is mixed with it. When this is a smooth pastry the sugar is added. Finally, the fat is mixed with it.
Quite soon the pastry is a coherent whole. The gluten network has already been created. When the pastry is mixed for a longer time the gluten grow soft and the pastry looses its elasticity. Only a short time after, the pastry can be put into pieces without stretching it; now the pastry is ‘short’. The mixing takes 15 minutes.
In mixing a lot of energy is put into the pastry, which gives tension to the pastry. Because of this stress the pastry can contract and shrink. To prevent the pastry from shrinking, it should be laid to rest for 30 minutes. The pastry is covered in order to prevent it from drying out. After 30 minutes of rest only 10% of the original stress is left.
To give the pastry its desired thickness it is laminated. Laminating means that the pastry is let through several rollers after which it has a thickness of 10 mm.
Because again a lot of energy is put into the pastry when it is laminated it is possible that the pastry shrinks again. In order to let the pastry rest a moment of rest is implemented, which is the second rest of the pastry. In rolling the pastry energy is put in only to one direction, therefore, it can only shrink in that direction. By letting a small piece of the conveyor belt (on which the pastry is transported) go more slowly the pastry undulates there. After that the conveyor belt continues on its normal speed. This can be made by placing the following pieces after each other: a long conveyor belt with a standard speed, a short conveyor belt with a slow speed and again a long one with standard speed.
Wholes are pierced into the pastry to let the gas of the ammonium hydrogen carbonate escape. By these wholes the gas in the middle of the cookie can escape too.
Despite of a second rest for the pastry, it still shrinks somewhat, especially while baking it. To get round cookies the pastry is punched in ovals instead of circles. By adapting the form of the pastry in this way it is possible to make a round cookie.
The cookies are baked on 230ºC. After that they have an auburn color. This brown color is the result of Maillard reactions, a reaction at high temperatures between reducing sugars and proteins. Beside the brown color the Maillard reaction also forms the aromas.
Under the influence of the high temperature the rising agents are converted into gaseous components, which cause the rising. The ammonium gas and carbon dioxide that are formed by ammonium hydrogen carbonate can escape through the wholes that are pierced in the pastry. The conveyor belt on which the pastry is transported is also of importance. If an open one is used the gas can also escape underneath. If a closed one is used the gas cannot escape underneath and this creates little wholes at the underside of the cookie.
A biscuit is a hard and crunchy cookie.
A basic recipe for the pastry of a biscuit is: 100 kg flour, 30 kg sugar, 25 kg water, 20 kg fat, 1.5 kg salt, 0.5 kg sodium hydrogen carbonate, 0.5 kg ammonium hydrogen... volle Beschreibung