Condensed milk is a milk product, made from fresh milk or goat's milk that has been sterilized and concentrated into a beverage, which is characterized by its ability to be stored for a longer period of time. Condensed milk is a kind of "concentrated milk", is the fresh milk by vacuum concentration or other methods to remove most of the water, concentrated to the original volume of 25% to 40% of the dairy products, and then add 40% of the cane sugar canned.

Condensed milk can be stored for a long time after it is opened and refrigerated. Because condensed milk is highly concentrated whole milk, added nearly saturated sugar, when the Europeans invented such a high concentration of portable dairy products, is to travel long distances both easy to carry, but not easy to spoil. Because of the high concentration of desserts, will make the bacterial cells of the water is penetrated and can not survive, so condensed milk after opening the lid is generally refrigerated on it.

Condensed milk processing due to the use of raw materials and add different accessories, can be divided into sweetened condensed milk (sweetened condensed milk), light condensed milk, skimmed condensed milk, semi-skimmed condensed milk, fancy condensed milk, fortified condensed milk and modulated condensed milk. China used to mainly produce whole sweetened condensed milk and light condensed milk. In recent years, with the development of China's dairy industry, condensed milk has been withdrawn from the mass consumption market of dairy products.

However, in order to meet the special requirements of different consumers for the concentration, flavor and nutrition of fresh milk, the use of appropriate concentration technology will be moderately concentrated milk (flash evaporation) and the production of "concentrated milk" will still have a certain market.

There are many ways to categorize condensed milk, the main ones are as follows:

According to whether or not sugar is added can be divided into: sugar condensed milk (i.e., sweetened condensed milk), unsweetened condensed milk (i.e., light condensed milk).

By whether the raw milk is skimmed or not can be divided into: whole condensed milk, skimmed condensed milk and semi-skimmed condensed milk.

By the type of additives can be divided into: cocoa condensed milk, coffee condensed milk, vitamins and other fortified condensed milk, as well as simulation of human milk composition of the infant formula condensed milk.