Originating as a part of Italian cuisine, the dish has become popular in many different parts of the world. A shop or restaurant where pizzas are made and sold is called a “pizzeria”. The phrase “pizza parlor” is also used in the United States. The term pizza pie is dialectal, and pie is used for simplicity in some contexts, such as among pizzeria staff.
In restaurants, pizza can be baked in a gas oven with stone bricks above the heat source, an electric deck oven, a conveyor belt oven or, in the case of more expensive restaurants, a wood- or coal-fired brick oven. On deck ovens, the pizza can be slid into the oven on a long paddle called a peel and baked directly on the hot bricks or baked on a screen (a round metal grate, typically aluminum). When making pizza at home, it can be baked on a pizza stone in a regular oven to imitate the effect of a brick oven. Another option is grilled pizza, in which the crust is baked directly on a barbecue grill. Greek pizza, like Chicago-style pizza, is baked in a pan rather than directly on the bricks of the pizza oven.
Neapolitan pizza (pizza napoletana): Authentic Neapolitan pizzas are made with local ingredients like San Marzano tomatoes, which grow on the volcanic plains to the south of Mount Vesuvius, and Mozzarella di Bufala Campana, made with the milk from water buffalo raised in the marshlands of Campania and Lazio in a semi-wild state (this mozzarella is protected with its own European protected designation of origin). According to the rules proposed by the Associazione vera pizza napoletana, the genuine Neapolitan pizza dough consists of Italian wheat flour (type 0 or 00, or a mixture of both), natural Neapolitan yeast or brewer’s yeast, salt and water. For proper results, strong flour with high protein content (as used for bread-making rather than cakes) must be used. The dough must be kneaded by hand or with a low-speed mixer. After the rising process, the dough must be formed by hand without the help of a rolling pin or other mechanical device, and may be no more than 3 mm (¹⁄₈ in) thick. The pizza must be baked for 60–90 seconds in a stone oven with an oak-wood fire. When cooked, it should be crispy, tender and fragrant. Neapolitan pizza has been given the status of a “guaranteed traditional specialty” in Italy. This allows only three official variants: pizza marinara, which is made with tomato, garlic, oregano and extra virgin olive oil (although most Neapolitan pizzerias also add basil to the marinara), pizza Margherita, made with tomato, sliced mozzarella, basil and extra virgin olive oil, and pizza Margherita extra made with tomato, buffalo mozzarella from Campania in fillets, basil and extra virgin olive oil.
Lazio style: Pizza in Lazio (Rome), as well as in many other parts of Italy is available in two different styles: (1) Take-away shops sell pizza rustica or pizza al taglio. This pizza is cooked in long, rectangular baking pans and relatively thick (1–2 cm). The crust is similar to that of an English muffin, and the pizza is often cooked in an electric oven. It is usually cut with scissors or a knife and sold by weight. (2) In pizza restaurants (pizzerias), pizza is served in a dish in its traditional round shape. It has a thin, crisp base quite different to the thicker and softer Neapolitan style base. It is usually cooked in a wood-fired oven, giving the pizza its unique flavor and texture. In Rome, a pizza napoletana is topped with tomato, mozzarella, anchovies and oil (thus, what in Naples is called pizza romana, in Rome is called pizza napoletana).
Other types of Lazio-style pizza include:
Sicilian-style pizza has its toppings baked directly into the crust. An authentic recipe uses neither cheese nor anchovies. “Sicilian” pizza in the United States is typically a different variety of product made with a thick crust characterized by a rectangular shape and topped with tomato sauce and cheese (and optional toppings). Pizza Hut’s “Sicilian Pizza”, introduced in 1994, is not an authentic example of the style as only garlic, basil, and oregano are mixed into the crust;
White pizza (pizza bianca) uses no tomato sauce, often substituting pesto or dairy products such as sour cream. Most commonly, especially on the east coast of the United States, the toppings consist only of mozzarella and ricotta cheese drizzled with olive oil and spices like fresh basil and garlic. In Rome, the term pizza bianca refers to a type of bread topped with olive oil, salt and, occasionally, rosemary leaves. It’s also a Roman style to top the white pizza with figs, the result called pizza e fichi (pizza with figs);
Ripieno or calzone is a pizza in the form of a half moon, sometimes filled with ricotta, salami and mozzarella; it can be either fried or oven baked.
Due to the wide influence of Italian and Greek immigrants in American culture, the United States has developed quite a large number of regional forms of pizza, many bearing only a casual resemblance to the Italian original. During the latter half of the 20th century, pizza in the United States became an iconic dish of considerable popularity. The thickness of the crust depends on what the consumer prefers; both thick and thin crust are popular. Often, "Americanized" foods such as barbacued chicken and bacon cheeseburgers are used to create new types of pizza. Mexican pizza, or taco pizza, is also popular in the U.S., popularized by the Taco Bell chain.
American pizza often has vegetable oil or shortening (often, but not always, olive oil) mixed into the dough; this is not as common in Italian recipes (for example, the pizza dough recipe in the influential Italian cookbook Il cucchiaio d’argento does not use oil). This can range from a small amount in relatively lean doughs, such as New York style, to a very large amount in some recipes for Chicago-style deep-dish dough. In addition, American pizza (at least thin-crust) is often made with a very high-gluten flour (often 13–14% protein content) of the type also used to make bagels; this type of flour allows the dough to be stretched rather thinly without tearing, similar to strudel or phyllo dough.
Various toppings may be added, most typically:
In some pizza recipes the tomato sauce is omitted (termed “white pizza”), or replaced with another sauce (usually garlic butter, but sauces can also be made with spinach or onions). In the Philadelphia area there are also tomato pies—sauce only, or sauce with ripe Roma tomatoes and spices but no cheese—and upside-down pizzas, i.e., the cheese on the bottom and topped with sauce. Pizza is normally eaten hot (typically at lunch or dinner), but is sometimes eaten as cold leftovers for breakfast.
New York-style pizza is a style originally developed in New York City by immigrants from Naples, where pizza was created. It is often sold in generously sized, thin and flexible slices. It is traditionally hand-tossed, moderate on sauce, and moderately covered with cheese essentially amounting to a much larger version of the Neapolitan style. The slices are sometimes eaten folded in half, or even stacked, as its size and flexibility may otherwise make it unwieldy to eat by hand. This style of pizza tends to dominate the Northeastern states, and is very similar to the basic style common through the United States and known simply as pizza. Many pizza establishments in the New York metropolitan area offer two varieties of pizza: “Neapolitan”, or “regular”, made with a relatively thin, circular crust and served in wedge-shaped slices, and “Sicilian”, or “square”, made with a thicker, rectangular crust and served in large, rectangular slices.
Chicago-style pizza, or Chicago-style deep-dish pizza, contains a crust which is formed up the sides of a deep-dish pan. It reverses the order of some ingredients, using crust, cheese, filling, then sauce on top. Some versions (usually referred to as stuffed) have two layers of crust with the sauce on top. The invention of deep-dish pizza occurred in America and transcends a single ethnic origin. Deep-dish pizza was invented by Ike Sewell and Ric Riccardo and first served in 1943 at Pizzeria Uno, which is still operating along with its twin restaurant, Pizzeria Due, in the River North neighborhood.
Chicago-style thin-crust pizza has a thinner crust than Chicago-style deep dish, and is baked flat rather than in a deep dish pan. The crust is thin and firm enough to have a noticeable crunch, unlike a New York-style pizza, yet thick enough to be soft and doughy on the top. The crust is invariably topped with a liberal quantity of southern-Italian style tomato sauce, which is usually quite herbal or highly spiced, and typically contains no visible chunks of tomato. Next, a layer of toppings is added, and a layer of mozzarella cheese which frequently separates from the bottom crust due to the quantity of tomato sauce. Chicago-style thin crust pizzas are cut into three-to-four-inch (8–10 cm) squares, also known as “party cut”, as opposed to a “pie cut” into wedges. The small size of the squares makes it unnecessary to fold the slices. Chicago-style pizza is prevalent throughout the Midwestern US. In fact, most of the neighborhood pizza parlors in Chicago and the rest of the Midwest serve Chicago-style thin crust, not deep dish as is commonly assumed. Chains that are well known for Chicago-style thin-crust pizza are Aurelio's Pizza, Home Run Inn and Rosati's Pizza.
St. Louis-style pizza is a variant of Chicago-style thin crust that is popular in and around St. Louis, Missouri. The most notable characteristic of St. Louis-style pizza is the distinctively St. Louisan Provel cheese used instead of (or rarely in addition to) the mozzarella common to Chicago-style thin crust.
California-style pizza refers to pizza with non-traditional ingredients, especially those that use a considerable amount of fresh produce. A Thai-inspired chicken pizza with peanut sauce, bean sprouts, and shaved carrots is a popular variant in California-style pizza restaurants, as are pizzas that use chicken and barbecue sauce as toppings. The style was invented by Chez Panisse restaurant in Berkeley, California, and popularized by the California Pizza Kitchen chain, along with Wolfgang Puck’s various fine dining and casual restaurant chains and retail products.
Old Forge-style pizza is a rectangular, double-crust pan pizza, made in both red and white varieties, that originated in the town of Old Forge, Pennsylvania, located between the cities of Scranton and Wilkes-Barre in Northeast PA. Red pizza is made with tomato sauce and cheese, while white pizza uses no sauce but is stuffed with a blend of cheeses and topped with olive oil and rosemary leaves. The cheese is believed to be a blend of traditional mozzarella and some domestic varieties.
Greek pizza is a variation popular in New England; its name comes from it being typical of the style of pizzerias owned by Greek immigrants. It has a thicker, chewier crust and is baked in a pan in the pizza oven, instead of directly on the bricks. Plain olive oil is a common part of the topping, as well as being liberally used to grease the pans and crisp the crust. Variations in other parts of the country include using feta cheese, Kalamata olives, and Greek herbs such as oregano.
Hawaiian pizza has “Canadian bacon” (or sliced ham) and pineapple toppings with Mozzarella cheese. This type of pizza is especially popular in the western United States, and is also a popular topping combination in Australia, Canada, and Sweden, but notably not in Hawaii. This type is also common within the EU, where it is known as pizza Hawaii.
English muffin and French bread pizza and pizza bagels are common convenience pizzas made at home in an oven or toaster, usually with a simple topping of tomato sauce, sliced or shredded cheese, and perhaps pepperoni. French bread pizza is sometimes available commercially as a frozen meal.
New Haven-style pizza, also known as apizza, popular in southern Connecticut. It has a thin crust that varies between chewy and tender, depending on the particular establishment. The default version is a “white” pizza topped with only garlic and hard cheeses; customers who want tomato sauce or mozzarella cheese have to ask for them explicitly. Apizza has a very dark, “scorched” crisp crust that offers a distinctive bitter flavor, which can be offset by the sweetness of tomatoes or other toppings.
In the 1980s Australian pizza shops and restaurants began selling gourmet pizzas, essentially pizzas with upmarket ingredients such as salmon, dill, rocket, bocconcini, tiger prawns, and even such outré toppings as kangaroo, emu and crocodile meats. Wood-fired pizzas, cooked in an impressive-looking ceramic oven heated by wood fuel, are also popular.
Pizza is also found as a frozen food in grocery stores and supermarkets. Some popular brands of these in the US are Tombstone pizza, DiGiorno's, Red Baron and Home Run Inn. A considerable amount of food technology ingenuity has gone into the creation of palatable frozen pizza. The main challenges include preventing the sauce from combining with the dough and producing a crust that can be frozen and reheated without becoming rigid. Modified corn starch is commonly used as a moisture barrier between the sauce and crust. Traditionally the dough is somewhat pre-baked and other ingredients are also sometimes pre-cooked. More recently, frozen pizzas with completely raw ingredients have also begun to appear, as have those with “self-rising” crusts. Many grocery stores and supermarkets also sell fresh, ready-to-bake pizzas. Recently, nearly all of the frozen pizza makers like Jack's, Tony’s, Red Baron and Totino's, as well as the store brands have switched to a lower quality of pepperoni and sausage made with a combination of pork, beef and the recently added mechanically separated chicken.
Another form of uncooked pizza is available from take and bake pizzerias. This pizza is created fresh using raw ingredients, then sold to customers who take it home and bake it in their own ovens and microwaves. Many supermarkets also offer this service.
Italy has also requested that the European Union safeguard some traditional Italian pizzas, such as “Margherita” and “marinara”. The European Union enacted a protected designation of origin system in the 1990s.
However, it should also be noted that commercially made fast food pizza is very different from well made Italian pizza, particularly from a good restaurant which is concerned with using only good ingredients, or even more so in a homemade pizza. The salt and saturated fat content of a homemade pizza is usually far less if using original recipes. Mozzarella cheese is not as fatty as many other cheeses, and should be used judiciously in any event. Feta cheese, which has an even lower saturated fat content, is often used in homemade pizza recipes. There is the added bonus of being able to include other healthy ingredients as well, such as fresh tomatoes, peppers, mushrooms, rocket, spinach, courgettes (baby marrow) and eggplant, as just a few examples.
Health conscious pizzaiolos (pizza makers) are also able to substitute some of the sodium chloride (common salt) with potassium chloride, which is almost indiscernible in taste, is far healthier and has little effect on those suffering from high blood pressure.
According to The Pizza Gourmet.com, nutrition researchers in Europe investigating the eating habits of people suffering from cancer of the mouth, oesophagus, throat or colon, made an interesting finding with regard to eating pizza. 3,300 sufferers were questioned regarding their eating habits, and their answers compared to over 5,000 healthy respondents.
Those who ate pizza at least once a week had less chance of developing cancer, they found. Dr Silvano Gallus, of the Mario Negri Institute for Pharmaceutical Research in Milan, who led the research said: "We knew that tomato sauce could offer protection against certain tumors, but we did not expect pizza as a complete meal also to offer such protective powers." Nicola O'Connor, of Cancer Research UK, told BBC News Online: "This study is interesting and the results should probably be looked at in the context of what we already know about the Mediterranean diet and it's association with a lower risk of certain types of cancer.
"The secret is probably lycopene, an antioxidant chemical in tomatoes, which is thought to offer some protection against cancer, and which gives the fruit its red color.
"But before people start dialing the local pizza takeaway, they should consider that some pizzas can be high in saturated fat, salt and calories". In contrast to the classic Italian pizza used in the research, most UK pizza takeaway varieties are often loaded with high fat cheeses and fatty meats and yeast, a high intake of which can contribute to obesity, itself a risk factor for cancer. "Our advice is to enjoy selected Italian pizza (ie. healthy pizza) in moderation as part of a balanced diet that includes plenty of vegetables and fruit."
Italian Carlo La Vecchia, a Milan-based epidemiologist said Italian pizza lovers should not see the research as a license to indulge their fondness for pizza food. "There is nothing to indicate that pizza is the only thing responsible for these results." He continued: "Pizza could simply be indicative of a lifestyle and food habits, in other words the Italian version of a Mediterranean diet." A Mediterranean diet is rich in olive oil, fiber, vegetables, fruit, flour and freshly cooked food - including traditional Italian healthy pizza.