Microwaves are killing the can. Sales of canned foods are plummeting with volumes down 4.3% year-on-year. And the biggest success story in the canned category is not, in fact, in a can. Heinz's yoghurt pot-style Snap Pots of baked beans and spaghetti have notched up an impressive £22.6m in sales and account for 4.2% of the baked beans market. Sainsbury's has been quick to follow with its own Snack Pots. Consumers seem to have fallen for the little plastic pots' microwaveability.

Elsewhere, fish brand Princes has followed petfood's lead and introduced microwaveable pouches of tuna. And Young's has even made fish fingers that can be zapped in the microwave without going soggy.

Heinz argues Snap Pots are also easier and safer to open and, should you not be able to finish a whole one, can be stored in the fridge.

Can makers are keen to argue microwave cooking does not spell the end of the can, and that new formats can lift the whole sector by offering variety. But with convenience and speed the modern holy grails, the retro craze isn't extending to the can.