Why Chicago Deep Dish Pizza Puts The Sauce On Top

It's no secret that, in Chicago, pizza is more than just a utility slice. It's a staple of the culture, a big role to play — which might be part of the reason why Chicago-style deep dish pizza is such a physically big slice. Finished, it clocks in at roughly two inches tall, and chowing down on it is more of a sit-down knife-and-fork deal than an on-the-go slice (don't forget the napkins). And in fact, many do insist that Chicago-style deep dish isn't "pizza" at all, but rather a casserole of sorts. 

This gastronomic iconoclast famously subverts the standard pizza paradigm by layering the sauce on top. To assemble, the dough gets pressed into a round, high-edged pie pan, and then layered with generous mozzarella, followed by toppings, then sauce. When it comes to Chicago-style deep dish pizza (not to be confused with tavern-style pizza or Detroit-style pizza, which are also pretty thick), the unique layering method isn't just a matter of preference. There's a utilitarian explanation for the unconventional order.

The hearty Chicago deep-dish pizza is a formidable animal, and as such, it requires a longer-than-average time in the oven to cook all the way through (about 30 minutes). If the cheesy layer was on top, it'd scorch in the heat. Enter: That heroic tomato-y top layer protecting the gooey cheese underneath like a tasty fire blanket. The top sauce helps keep the crust from drying out during all that time in the oven, as well.

Because that saucy top layer features so prominently in Chicago deep dish, pizzerias making this type of pie often use higher-quality tomatoes and spend more attention to craft when making flavorful sauces compared to other types of pizza, in which a "meh" sauce can totally slide. Chicago-style deep dish is characterized by thick, chunky tomato sauce dotted with toothy crushed tomatoes, giving it an arguable advantage over other pureed pizza sauces that feel canned at best. That chunky thickness also prevents the sauce from turning into a runny mess as it cooks, instead baking firmly in place.

On the palette, that tomato sauce boasts enough acidity to cut through the richness of the abundant cheese and crust, and in Chicago deep dish, the crust is an essential component. The high-edged crust is baked in a round pie pan with physically taller edges than the average flat pie pan – a far cry from thin, foldable New York-style pizza (R.I.P. dollar slice). That thicker crust provides a sturdy enough vehicle to support more sauce, more cheese, and an overall deeper pie.

Crumbled sausage is the most common Chicago-style pizza topping beyond sauce and cheese. Another popular regional order is the "Chicago special," which loads fennel sausage, mushrooms, onions, and green bell peppers beneath the sauce. Luckily for pizza lovers nationwide, this Midwestern legend has become so iconic that it's also available at pizzerias outside of Chicago.