When choosing bivalves, look for:
- brightly coloured, lustrous shells;
- intact shells that are closed, or close when tapped or gently squeezed;
- a pleasant fresh sea smell.
Ideally, learn to shuck your own oysters, or at least buy them freshly shucked and not washed.
Scallops are one of the few bivalves not generally sold live, though chefs often prefer to buy them live and shuck them themselves. Raw scallops should be translucent and slightly ‘sticky’, indicating that they haven’t been frozen or stored in water (scallop meat is sponge-like and will quickly absorb water, turning opaque).