The mystery of heating up canned beans- What the tin says Cans of beans say "Heat for 3-4 min. DO NOT BOIL". Does anyone know why canned beans should not be boiled? Surely they were boiled when they were first cooked, so where's the problem?
Beans in the can are already well cooked--they are essentially pressure cooked as part of the canning process.

While only a speculation, it is highly likely that they are now fragile and bringing them to a full boil would mar their appearance--fewer whole beans--from the agitation.

There is nothing I am aware of from a safety aspect that would contraindicate boiling the beans again.