[Boil sugar or water]_Water and oil_How to choose
The cooking oil requires cooking oil. This is a very long process. People must be patient during the cooking process, so that the color and taste of the sugar can be better.It also needs to be matched with a suitable stirring speed. It may be necessary to use a high temperature for cooking. You must pay attention to the temperature to avoid the sugar concentration that is not enough.
(1) Boil sugar at normal pressure: Boil sugar at normal pressure is to boil sugar at normal atmospheric pressure, also known as open-boiled sugar or open-boiled sugar.
As the sugar concentration increases, its boiling point increases.
For example, the concentration of sucrose solution is 94.
At 9%, its boiling point is 130 ° C.
When the concentration is 98%, the boiling point is 160 ° C.
Therefore, if you want hard candy with a moisture content of 2%, you need to boil it to 160 ° C and cook it out.
When the sugar is boiled, the foam of the syrup is large and easy to burst. By boiling, the concentration gradually increases, the foam gradually becomes smaller, and the beating is slow.
As the temperature further increases, the concentration increases, the viscosity increases, the surface foam is smaller, and the beating is slower; the sugar solution changes from light yellow, golden yellow to brown yellow.
At this time, you can take a small amount of sugar paste and drop it into cold water. If you immediately form a hard ball, chew and crack, you will reach the end of boiling sugar.
Of course, you can also insert a thermometer to control the temperature of the pan.
The acidity of the sugar solution decreases, the boiling temperature exceeds, and the longer the cooking time, the amount of reducing sugars, decomposition products, and chromaticity may also be used.
In order to obtain the ideal product, these three conditions should be controlled in boiling sugar at normal pressure.
(2) Continuous vacuum boiling sugar: The advantage of vacuum boiling sugar is to use vacuum to reduce the boiling point of the sugar solution, evaporate a lot of water at low temperature, and avoid the decomposition and discoloration of sugar at high temperature to improve the product quality and shorten the sugar boiling time.Productivity.
The continuous vacuum boiling device is mainly composed of three parts: heating, evaporation and vacuum concentration.
The main part of the heating part is a snake-shaped heating tube. The sugar liquid is heated to about 140 ° C in a very short time through the snake-shaped heating tube, and the concentration is close to 96%.
Then enter the evaporation chamber to remove the secondary steam in the sugar solution; then the sugar solution enters the vacuum concentration chamber and the vacuum degree is maintained above 700 mmHg, and then a small amount of water is removed. The temperature of the sugar paste drops to 112-115 ° C and flows into the rotating pot., Completed the sugar operation.
(3) Continuous vacuum film boiling sugar: Vacuum film boiling sugar uses a sandwich pot, the inner layer of which is equipped with a rotor shaft where many scrapers are placed. When the rotor shaft rotates, the scraper rotates along the inner wall of the sandwich pot, and the top is provided with a row.Air fan.