Anyway, when buying seafood (including oysters), it must be fresh, and the taste of chilled (live and frozen in time) is much worse, not to mention dead.
When buying oysters, the first criterion is whether they are fresh. A live oyster can open its mouth slightly, pat its shell lightly, and close it quickly, while the indifferent oyster is obviously dead. In addition, if it is a fresh oyster cooked by heating, the closed shell will open with heating. Those oysters with closed shells from beginning to end are dead oysters, so don't eat them.
Oysters "have mud in their bellies", and some have a normal earthy smell. But it's too fishy or smells bad. It should be that the dead oyster has gone bad. Stale oysters are not delicious no matter how they are cooked.
I have bought oysters several times, using the method of boiling and dipping. The impression is that there is a big difference between "death" and "living". Alive, no smell after prying open; Oyster skirt is energetic, oyster meat is elastic and delicious; And the dead (basically not coquetry) are tasteless.
Where is the oyster delicious? In my opinion, Dalian Bay is better. Seafood in the "Bay", including oysters and crabs, is tender because the sea is slow, while that in the far sea is "firewood". Here, the price of seafood produced in Bohai Bay (local) is generally higher than that of imported seafood. The oyster in Dalian Bay is recommended because there is pollution in Bohai Bay, but Dalian Bay is much better. Bohai Sea is a semi-closed inland sea in China, with poor self-purification ability, developed surrounding industrial cities and serious seawater pollution. The whole coastal area of Bohai Sea is polluted except a few coastlines near Qinhuangdao South, Beidaihe and Dalian in Hebei Province.
It is suggested that you must choose fresh oysters to eat. After this pass, no matter how processed, they are all fresh and delicious.