Can You Eat Clams That Didn't Open While Cooking? 

Fresh clams are a flavor-packed and nutritious shellfish delight. However, before you tuck into a clamshell-loaded seafood stew or a fragrant plate of steamed clams, you may wonder if you can eat the clams that didn't open during the cooking process. The short answer is no, it is not advisable to eat clams that remain closed after being cooked. 

The official word from the FDA is that clamshells should open during cooking, and any clams that don't open during the cooking process should be discarded. Clams that don't open during cooking may be contaminated with bacteria or viruses, and could transmit food-borne diseases.

Ideally, the process of cooking fresh clams should start with closed, live, healthy clams, and end with open, dead clams (hopefully soaking in a delicious sauce or crowning one of the many regional variations of clam chowder). Healthy live clams usually keep their shells tightly shut with contracted muscles. During the cooking process, the clams die and their shells naturally open as their muscles relax. If the clams don't open during cooking, it's a sign that they may be contaminated, and are risky to consume.

The primary bad reasons a clam might not open during cooking are twofold. One possibility is that the clam died before being cooked. You should never eat a clam (or any shellfish) that died before cooking because the bivalves decompose rapidly, presenting a high risk of bacterial growth. Another possibility is that the clam was alive before cooking, but was already contaminated with bacteria or viruses. Either way, clams that don't close while cooking are not safe to consume and should be chucked. 

In addition to throwing away any clams that remain closed after cooking, there are some preemptive steps you can take to ensure your clams are healthy and safe to eat. Before getting started, chuck any clams whose shells are broken or have cracks, or open shells that do not close when lightly tapped – these clams are already dead. 

It's also a good idea to use your nose to conduct a simple "sniff test." Fresh clams should smell like a clean ocean breeze, a little salty and briny but not overly fishy or sour. If sniffing your clams causes you to recoil, please chuck them. Lastly, thoroughly clean your shellfish to avoid a gritty bite. Fresh, in-shell clams are a wonderful treat, but it's best to err on the side of caution and throw away any clams that didn't open while cooking.