Five foods with the longest shelf life

　　1. Vinegar: Vinegar has antibacterial and sterilizing effects and can be used to preserve food and preserve it, such as pickling. The shelf life of vinegar is relatively long, but it is also affected by technology and raw materials. The mature vinegar with better craftsmanship is sealed in a jar and placed underground. The older it is, the more mellow the flavor will be.

　　2. Solid sugar: Solid sugar includes commonly used white sugar, soft white sugar, rock sugar, single crystal rock sugar, etc. Solid sugar has little internal water content and strong osmotic pressure, which is not conducive to the growth of microorganisms and is difficult to be contaminated. Sugar is also often used to preserve food, such as candied fruits, preserved fruits, etc. However, sugar easily absorbs moisture. If it is placed improperly and its properties change, it will be contaminated by microorganisms.

　　3. Honey: Fresh and mature honey is a transparent or translucent colloidal viscous liquid. Sugar accounts for more than 3/4 of the total amount of honey. It has low water content and neither bacteria nor yeast can survive in honey. In addition, honey also contains 0.1%-0.4% bacteriostatin. Therefore, mature honey will not deteriorate easily if left for a long time. But if it is not mature honey or a low-quality product that has been mixed with water, it will ferment, bubble, and become sour after being left for a period of time, making it inedible.

　　4. Liquor: Liquor with an alcohol content of more than 10%, which is commonly known as wine with more than 10 degrees of alcohol, has a disinfecting effect in itself. Under sealed conditions, microorganisms are not easy to invade and reproduce, so they will never deteriorate. But this does not mean that the longer the wine is stored, the better. After 5 years, the taste of ordinary-flavor liquor will become lighter and the aroma will weaken; Maotai-flavor aged wine is a good wine, but it is still inconclusive whether the strong-flavor wine stored for many years is a good wine.

　　5. Table salt: The main component of table salt is sodium chloride, which has very stable chemical properties. Like sugar, table salt is often used to preserve food and is a natural preservative. However, if the iodized salt we often eat is not protected from light and high temperatures, the iodine content will be reduced if left for too long, but the quality of the salt will not change.