Two, the reason: yogurt in the shelf life of ten days after the yogurt will have precipitation taste deterioration, eat will cause food poisoning light food allergies appear.
Three, homemade yogurt method:
1, cleaned rough glass or porcelain bottles (canning jars can not be used because the mouth is too large prone to contamination of stray bacteria), full of milk;
2, with a clean double-layer plastic film to cover the mouth of the bottle, and bundled with string, string bundled to be loose, because in the process of heating the bottle will produce a lot of steam, such as bundled too tightly, the film will be bulging, easy to contaminate;
3, with the bottle of clean double-layer plastic film, and tied up with string, string bundled to be loose, as the bottle will generate many steam, such as bundled too tightly, the film will bulge, and the film will be bulging. Pollution can easily occur;
3, glass bottles containing milk into the pot to boil for 30 minutes, the water soaked milk surface is appropriate, do not cover the lid, and then remove the cooling to the back of the hand when not hot to touch can be poured into the 2% to 4% of the market for the sale of fresh pure yogurt, and then immediately tie the plastic film to ensure that the bottle of the anaerobic environment;
4, 10 hours at room temperature, the fresh milk milk coagulation As the tofu brain, yogurt is ready. Put the bottle of yogurt into the refrigerator at 0-5 ℃ for 2 to 4 hours, can be eaten (sugar can be added when sterilized, can also be added when eating, the amount of personal taste, but also can not be added);
5, in addition to the production of a separate small bottle, such as milk coagulation is very good, can be left as a strain, but can not be used many times, because the home can not guarantee the asepsis of the operation, the strain into the Refrigerated room can be. If the bottle mouth film on the drum, inside the gas production, we must take out the practical, can not be used as a strain.