Static Freezing
The following dynamic freeze, ingredient, addition and packing of ice-cream, is immediately transferred to the hardening chamber (-30C or below, or forced convection or plate-type conductivity freezers), where most of the remaining water freezes. Rapid solidification required for product quality, as it helps maintain a small crystals of ice the size of the distribution, which was established in scratches the surface of the freezer. Hardening slowly, too many chances for small ice nuclei formed in recrystallise, resulting in more large ice crystals and rougher product. Many factors need to be considered during the hardening process.
Main factors influencing the temperature difference between the heat transfer product and freezing medium, size of the product is subject to the freezing of the environment, and the heat transfer coefficient for a particular operation. The temperature of ice cream, if placed in a hardening of the room should be as cold as possible. Draw temperatures from trunk freezer limited need for packing of free-flowing product.
Adding ingredients and packaging operation should not raise the temperature of ice cream as he turns from the trunk of a freezer more than necessary. Melting point of the camera is also important for freezing and smooth product. The surface of ice cream, also need to be considered, especially when Packed in big bags or in shrink film, packages products.
Palletising or styling product should not prevent the rapid circulation of air and fast freezing. Heat transfer coefficients significantly increased through the use of forced convection systems. Evaporator should be free from frost outside and oil inside the coils, as these act to reduce the heat-transfer coefficients. Following rapid solidification, ice cream storage should happen at a low, constant temperature, as a rule, at -25C.
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Food refrigeration and freezing