A round, flaky, crispy crust, sweet tomato sauce, pepperoni slices, black olives and red onions. Pizza, although an Italian dish, is probably most popular in America where it is the dinner of choice at least one night a month in nearly every household. Worldwide it is a $30 billion-dollar-per-year industry and growing every year.

From Peasant Dish to Haute Cuisine

In ancient times many civilisations created dishes of flat bread with various herbs and toppings. More than a few Mediterranean peoples can claim to have 'invented' the pizza, and the fact is that most of them did. A staple for the poor, it was a matter of necessity that food could be eaten without utensils, and the 'plate' it was served on could be eaten as well.

Modern pizza, as most people recognise it, has evolved from pizzas made by peasants in Naples, Italy. They made a bread crust from flour, water and yeast, topped it with olive oil, herbs, cheeses, sometimes even leftovers, and baked the whole thing in a stone oven.

Given that most pizza connoisseurs consider tomato sauce to be a key and defining ingredient, it may be surprising that pizza pre-dates the introduction of tomatoes to Europe. Tomatoes reached Italy by way of Spain in the early 1500s but were thought at first to be poisonous. It was several decades before tomatoes topped a flatbread in the name of pizza.

Key Events in the Evolution of Pizza

• 1522: The tomato arrives in Italy from Peru and Ecuador courtesy of Spanish conquistadors.
• 1830: Antica Pizzeria Port'Alba, widely considered the first pizzeria in the world¹, opens in Naples, Italy. They are still serving pizza.
• 1889: Pizzaiolo (pizza chef) Raffaele Esposito of Naples creates pizzas at the request of Queen Margherita di Savoia of Italy. Her favourite is a pizza consisting of tomatoes, mozzerella and basil (red, white and green, the colours of the Italian flag), which later became known as Pizza alla Margherita, the standard on which all modern pizza is based.
• 1905: Italian immigrant Gennaro Lombardi opens the first pizzeria in the United States in New York City. Lombardi's is also still open.
• 1943: Ike Sewell introduces Chicago-style deep dish pizza at his Pizzeria Uno restaurant in Chicago, Illinois. Pizzeria Uno continues to sell Chicago-style pizza nationwide.
• 1946 - 8: Soldiers returning from World War II spread the word about pizza having tried it while stationed in Italy; popularity of pizza increases.
• 1957: Frozen pizzas appear in supermarkets for shoppers to take home and bake in their own ovens.
• 1958: The first Pizza Hut opens in Wichita, Kansas. Pizza Hut goes on to become the largest pizza chain worldwide. In 2006 worldwide sales exceed 1.7 million pizzas daily.

The Perfect Foundation for a Masterpiece

No matter what the ingredients constructing a pizza are, a pizza must have a crust. Traditionally, an authentic pizza crust is made from flour, water and yeast and is shaped entirely by hand. Inevitably, over the centuries several variations have evolved.

Hand-tossed crust is exactly that - pizza dough that is shaped by tossing it spinning into the air by hand, catching it and tossing it again until the desired diameter and thickness is achieved. This is a technique perfected by pizza chefs with a flair for the dramatic; it's hard to think of the word 'pizzeria' without the accompanying image of doughy discs flying through the air. The advantage of tossing dough by hand is that it creates a near perfectly-shaped round crust for pizza.

The dough for hand-tossed crust can also be shaped by hand by being pressed or rolled onto a pan or stone. Hand-shaping gives the crust a more irregular finish, and if the chef is using a square stone or pan the pizza can be square instead of round.

Pan and deep dish crusts are not the same, no matter how much certain pizza outlets would like us to think that they are. Pan crust is baked in a metal pan that is between an inch and an inch and-a-half deep, and is nearly as thick as the pan is deep. This is crowned with a single layer of toppings as one would a more traditional crust, and the crust doesn't rise much during baking. The result is a very thick crust pizza that is filling because it is mostly bread. Deep-dish, on the other hand, is pressed into the bottom and up the sides of a similar deep pan, then filled with several layers of toppings.

Thin crust is about the thickness of a saltine cracker, and about as crispy as well. The advantage of thin crust is that the toppings are the focus of the pizza. Thin crust pizza is more likely to blacken when it's fired, giving it a distinct flavour. Pizza in Italy is usually made on thin crust, unless it is from Naples or the Campania region, where a thicker crust is more typical.

Crowning Glory

Original Neapolitan pizzas featured toppings such as herbs, mushrooms, olives and anchovies on olive oil-basted crust.

Most modern pizzas will have some variety of tomato sauce slathered over the crust. This sauce can be sweet or spicy, bold or mild. It can be absent as well; some pizzas will have a pesto base or alfredo sauce. The sauce not only adds flavour but serves to hold additional toppings in place.

Many varieties of Italian pizzas have been topped the same way for centuries. In addition to the Pizza Margherita, traditional Italian pizzas include:

• Marinara - simply tomato, garlic, olive oil and oregano, with no cheese.
• Quattro Formaggi - four cheese; usually mozzarella with a combination of three other cheeses which might be stracchino, fontina, gorgonzola, ricotta, groviera, pecorino or parmesan.
• Quattro Stagioni - or four seasons; tomato and mozzarella with olives, mushrooms, artichoke hearts, and prosciutto ham arranged in quarters instead of being all mixed together.

In the United States it's difficult to find a pizzeria that does not offer pepperoni. It's by far the favourite choice of a nation that consumes more than 250 million pounds of pepperoni each year. Other standard pizza staples include Italian or pork sausage, ham, bacon, mushrooms, olives, onions, peppers and mozzarella or provolone cheese.

Gourmet pizzas are making their way into the mainstream market as well, broadening the roster of possible toppings somewhat. Speciality pizzas might include spinach, tofu, broccoli, chicken, steak, shrimp and other seafood, as well as gouda, feta and cheddar cheeses. Pizzas might also echo other types of food: a Mexican pizza² will have Mexican spiced beef with onions, olives, salsa and jalepenos; a barbecue pizza would use barbecue sauce instead of tomato sauce with chicken and white cheddar cheese.

Pizza - It's Not Just for Supper Any More

The popularity and versatility of pizza has facilitated its ambition to take over other daily meals. A pizza with eggs, bacon, potatoes and cheese fills nearly all the requirements for a traditional American breakfast. For an appetiser, top a crust with cream cheese and fresh fruit or vegetables and cheddar. Pizza for dessert? Just top the crust with jam or chocolate, perhaps with a scoop of vanilla ice cream.

How to Get Your Pizza Fix

When craving a pizza, most people will pick up the telephone and call the local pizza delivery. Of the pizza franchises strewn across America and Britain more than 80% offer delivery or takeaway. Only half of these establishments offer dining rooms though, so for the best pizza experience it's best to seek out a genuine pizzeria (or what passes for one in the local market).

Pizzerias make several sizes of pizza:

• A six- or eight-inch pizza is usually an individual serving. If it's Chicago-style pizza the six-inch serves two and a nine-inch serves four. Trust us on this.
• A 12-inch pizza generally serves two; or three if the third is a small child.
• A 14-inch pizza serves three to four.
• A 16-inch pizza is usually considered the 'party size' and, if you're having a party, plan on ordering about a dozen. There will never be leftovers.
• If you order a pizza in Italy it will always be an individual serving.

Some pizzerias will offer freshly-made unbaked pizzas to be taken and baked at home. Some supermarkets will have these as well, but most supermarkets will instead have frozen, manufactured discs of crust with a pile of processed topping packaged and labelled 'Pizza'. The bulk of these should be avoided.

Most supermarkets will also offer pizza kits to 'do it yourself' at home. These will certainly please the palate of most three- to six-year-olds, but if you're going to make pizza at home it's worthwhile to find a decent recipe and make one from scratch. The toughest part will be making the dough, and there are several decent dough mixes and easy recipes to be had. Pre-made crusts are easy to find as well but quality varies; you may decide you're better off to start from scratch.

Pizza Fun

Pepperoni is the most popular topping in America, but around the world it's not unusual to find more uncommon toppings. Chicken is popular in the UK, India likes pickled ginger, in Japan it's squid or eel. Shrimp is a topping of choice in Australia, coconut in Costa Rica and red herring in Russia.

Pizza is similar to but not the same as tomato pie in the northeastern US. Tomato pie is constructed in the opposite order to pizza: cheese goes on the crust, meats and fillings over the cheese, tomato sauce over the top. Calzone is a variety of pizza where the toppings are piled on one half of the crust, then the crust is folded over and sealed creating a pizza 'sandwich'.

There are approximately 10,000 pizzerias in the UK, compared with more than 60,000 in the US - nearly 9,000 of which are in New York. Americans eat about 100 acres of pizza a day.

Pizza Express in the UK offers a Veneziana pizza, based on a centuries-old Venetian recipe, topped with onions, capers, olives, sultanas and pine kernels. A portion of the sales from this variety have been donated to the Venice in Peril fund since 1975. Venice in Peril helps preserve Venetian landmarks and artefacts dating prior to 1750.

The Vera Pizza Napoletana (Association of True Neapolitan Pizza) exists to protect the tradition of original, authentic pizza as it was first made in Naples, Italy. For a restaurant to join it must prepare its pizzas to exacting standards from the ingredients in the crust to specific toppings and the use of fresh mozzarella cheese made from Indian water buffalo milk. Pizzas must be fired in a specific type of wood-burning stone oven at temperatures between 400° and 430° Celcius.

According to the Guinness Book of Records, the largest pizza ever made was 122 feet 8 inches in diameter. It was made in Norwood, South Africa in 1990. The largest order for pizzas ever was placed by the VF Corporation of Greensboro, North Carolina, in 1998. The order for 13,386 pizzas was delivered by Little Caesar's Pizza locations nationwide.

Celebrate Pizza!

Oddly enough, International Pizza Day is celebrated on 9 February, a day that doesn't fall within National Pizza Month, which is October in the US. Neither of these coincide with the biggest month for pizza sales, January, with three of the top ten weeks for sales each year: the week of New Year's Day, the week of the NFL³ playoffs, and the week of the Super Bowl.

The International Pizza Expo takes place every March in Las Vegas, Nevada. The weekend exposition includes the World Pizza Games with competitions in dough stretching and dough tossing among others, and a recipe contest.

Also in March, Italy hosts the World Pizza Championship which features contests for speed, size, acrobatics and freestyle.