The shelf life of candy is generally 6 months, and it will be shorter in summer 1-2 months. When the average temperature in summer and autumn is above 30℃ and the humidity is high, the shelf life of all kinds of jelly candy and hard candy does not exceed 12 months. The shelf life of pressed/polished sugar is mainly affected by humidity. When the package is well sealed, the shelf life can reach 18~24 months.
Sugar is a polyhydroxy (two or more) aldehyde or ketone, which can become one of the organic compounds after hydrolysis. Chemically, because it is composed of carbon, hydrogen and oxygen, similar to the polymerization of carbon and water in the chemical formula, it is also called carbohydrate.
Types of sugar:
1. refined white sugar: short for sugar, it is granular crystal. According to the size of the crystal, there are three kinds: coarse sand, medium sand and fine sand. It is characterized by high purity, low moisture and few impurities. The content of domestic granulated sugar is higher than 99.45%, and the moisture content is lower than 0. 12%. According to the standard, it is divided into three grades: excellent grade, first grade and second grade, all of which are suitable for making bread and cakes.
2. Crude sugar: it belongs to unrefined raw sugar, with low purity, many impurities, large moisture and light yellow color, such as domestic No.2 sugar and imported Brazilian sugar and Cuban sugar.
3. Soft white sugar: the crystal is fine and even, the color is white, the texture is soft, the purity is lower than that of white sugar, the sugar content is about 98%, and the moisture content is lower than 2%. Because of its high cost, it is used in high-grade food.
4. Brown sugar (sliced sugar, yellow sugar): generally, it is made by indigenous method, with the most impurities and the lowest purity, but it has its special flavor and rapid coloring during baking, and also has certain uses.
5. Rock candy and borneol candy: inconvenient to weigh, high cost, less application, limited to high-grade food.
Reference to the above content: Baidu Encyclopedia-Sugar