1. When purchasing yogurt, we should first choose the products of well-known enterprises with large scale and good product quality and service quality. 2. Because of the different raw materials used in production, yogurt can be divided into pure yogurt, flavored yogurt and fruit yogurt. Therefore, when buying, you should carefully look at whether the labels on the product packaging are complete, especially the ingredient list and product ingredient list, so as to distinguish and choose the varieties that suit your taste. 3. Because the shelf life of yogurt products is short, usually one week, and it needs to be preserved at 2℃-6℃, the quantity should be less and more when purchasing yogurt. 4. Carefully distinguish between yogurt and yogurt drinks. The content of protein and fat in yogurt drinks is low, generally below 1.5%, so it is necessary to see clearly whether the product label indicates yogurt or yogurt drinks. 5. After the yogurt is opened, look at the shape of the yogurt first. Under normal circumstances, the clots of solidified yogurt should be uniform and fine, without bubbles and impurities, and a small amount of whey is allowed to precipitate. Stirred yogurt is a uniform fluid, without stratification and impurities. The normal color of yogurt should be yellowish or milky white, which is related to the fat content of milk. The higher the fat content, the more yellow the color.