Fresh oysters can stay overnight. Preservation method at room temperature: The bought oysters can actually be preserved at room temperature. First, choose a cool and dark environment. Secondly, you can prepare an appropriate amount of water, put the oysters into the water, add some salt to the water to create a seawater environment, and then soak the oysters in the water at room temperature. If the weather is hot, you can change the water 2~3 times a day, or add some ice to keep its temperature. If it is cold, it is usually enough to change the water once a day or two. Refrigeration: If you want to keep oysters for a long time, they still taste so delicious, you can keep them in the refrigerator. There are two ways to refrigerate. 1 Don't shell oysters, sprinkle some water on them, and then put them in a fresh-keeping box for refrigeration. 2 Take out the meat of the oyster, and then put it in a fresh-keeping bag or box for sealed preservation. Oysters that have not been shelled can generally be kept for ten days, and oysters that have been shelled can be kept for three to five days. But the sooner you eat, the better. It will not be fresh after a long time, affecting the taste.