second class meat

[workscottdal]

why is second class meat unsuitable for grilling

[Robert G]

Because it is insufficiently tender for fast cooking methods.

Generally speaking, the cheaper the cut the tougher the meat and the longer it should be cooked for. Taking beef, for example: fillet steak is extremely tender and should be grilled for as short a time as suits your preference, whereas stewing steak is not at all tender and so is best cooked in a casserole at low heat for several hours.

I guess it is something to do with the properties of the meat fibres and the way they soften, or even break down, when cooked.