Is there some sort of time-table for when a Cornish X bird goes from fryer to broiler to roaster (week by week)? Is there much difference in meat quality and tenderness between these stages, or is it more an issue of the size of the finished bird?
We usually consider live weight: 2.5 to 3 pounds = cornish game; 4 to 8 pounds = fryer; 9+ pounds = roaster or broiler. Others may have different weight ranges--you just pick the one you like--it doesn't matter they taste great any ol' way their cooked reguardless of size.
There are 4 traditional chicken meat classes: broiler, fryer, roaster and fowl. The traditional broiler age
range was from 7 to 12 weeks, and carcass weight from 1 to 2 1/2 lbs. (Squab broilers would be youngest and
smallest of these, typically Leghorn cockerels about 3/4 to 1 pound dressed.) The next age and weight group
was called the fryer. Traditional fryer age range was from 14 to 20 weeks, and carcass weight from 2 1/2 to 4
lbs. Traditional roaster age range was from 5 to 12 months, and carcass weight from 4 to 8 pounds. Most
roasters were butchered between 6 and 9 months. Hens and roosters 12 months and older were called fowl or
stewing fowl signifying that slow moist cooking methods were required.
Modern cornish X hybrids obviously grow a lot faster than heritage chickens so the timetables are different, but the weights are roughly still the same for the categories.