One of the identifying features of Chicago style pizza is its deep dish. In 1943, Ike Sewell created a deep-dish pizza. Ike's belief was if you made a pizza with massive amounts of ingredients (especially sausage) it would become a hearty meal choice for people. He was right, so he opened Pizzeria Uno, which specialized in deep-dish pizza and started the Chicago style phenomenon. Chicago style pizza is usually eaten with a knife and fork rather than the hands because it is so thick and heavy. The dough, which contrary to many beliefs, is not really thick, but has a biscuit-like texture and has raised high on the sides of seasoned deep dish pans to hold all of the ingredients in. The cheese is placed directly on the dough and toppings added on top of that. The top is cheesed and sauced with a chunky sauce with a light sprinkling of cheese scattered on top of the sauce. Cooking times are usually longer due to the overall thickness of the pizza. The dough used for this style usually contains between 10.5 and 11.5 percent protein and is under-mixed (not smooth). Table grade margarine is used in the pans to add a slight, fried crispness, contribute to the rich flavor and to aid as a release agent in helping to get the baked pizzas out of the pan.
By Tom Boyleshttp://www.pmq.com/mag/2003winter/pizzatypes.shtml