White sugar, brown sugar and rock sugar that people often eat are actually sucrose. The method of making sugar is not complicated. Juice sugarcane or beet, filter out impurities, then add a proper amount of lime water to the filtrate to neutralize the acid contained in it (because sucrose is easily hydrolyzed into glucose and fructose under acidic conditions), then filter, remove the precipitate, introduce carbon dioxide into the filtrate to precipitate lime water into calcium carbonate, and then filter. The obtained filtrate is an aqueous solution of sucrose. When sucrose water is evaporated, concentrated and cooled under reduced pressure in vacuum, reddish-brown slightly sticky crystals are separated out, which is brown sugar. To make white sugar, it is necessary to dissolve brown sugar in water, add appropriate amount of bone charcoal or activated carbon, adsorb colored substances in brown sugar water, filter, heat, concentrate and cool the filtrate, and a white crystal-white sugar appears. White sugar is much purer than brown sugar. Then, the sugar is heated to a proper temperature, and the water is removed to obtain colorless and transparent block crystal rock candy. It can be seen that rock sugar has the highest purity, the sweetest taste and of course the most expensive price. White sugar and soft sugar are both called white sugar, and the sucrose content is generally above 95%. White sugar is uniform and neat, hard, loose and dry, without impurities. It is the purest variety with the most sucrose in sugar, and it is also an easy-to-preserve sugar. Compared with sugar, soft white sugar has fine crystal particles, high water content, soft appearance and melt in the mouth. It is suitable to be directly sprinkled on food and snacks and dipped in it. It is difficult to preserve because of its high water content, and it is best to process it into small packages. Rock candy is made of white sugar by dissolving in water, removing impurities, clearing juice, evaporating, concentrating, cooling and crystallizing. Rock sugar is mild, has the effect of relieving cough and resolving phlegm, and is widely used in high-grade tonics and health products produced by food and pharmaceutical industries. Old people can also quench their thirst by containing rock sugar. Fine granulated sugar or granulated sugar is white granular crystal with high purity, and the sucrose content is above 99%. It is a kind of sugar with good quality, with low content of moisture, impurities and invert sugar, which is easy to preserve. Sugar powder is white powder, and the sugar particles are very fine. At the same time, there is about 3- 10% starch filler (generally corn starch) to prevent sugar particles from getting wet and tangled. Sugar powder can also be directly screened with a screen and directly screened on the finished product of West Point for surface decoration. Brown sugar crystals are delicate and soft, with different shades of color, including red, yellow, purple and black. High molasses, impurities and moisture; However, because it is rich in inorganic salts and vitamins, it has the effect of enriching blood and breaking blood stasis, and is especially suitable for pregnant women, children and anemia. Most of the brown sugar is produced by local methods. Rock candy is a large piece of sucrose crystal made by special crystallization method, which is translucent, low in impurity converted sugar and water content, good in quality and easy to store. Rock sugar is sweet in taste and flat in nature, and has the effects of tonifying the middle energizer, invigorating the stomach and moistening the lungs. It can be used for treating lung dryness and cough, sore throat, dry mouth, gastrointestinal weakness, and anorexia.