The pizza wars are heating up in Pasadena.

Anyone living in or around the city has likely noticed all the new pizza places that have cropped up. It started in 2011 when Blaze Fast Fire’d Pizza opened one of its first locations at 667 E. Colorado Blvd.

Several others have since joined the fray, including PizzaRev, Pieology, 800 Degrees Neapolitan Pizzeria, Pitfire Artisan Pizza and Pie Life Pizza, among others.

“I’ve lived here a year and I’ve already seen three new pizza places open,” said Amy DeVore, who recently stopped in at Blaze Pizza for lunch. “But that’s good — you can never have enough pizza!”

New Trends in Pizza

Blaze, Pieology, PizzaRev, Pitfire and 800 Degrees all fall into the “fast-casual” category of artisan pizzas that are served up at warp speed. So someone can walk in, custom order their personal pizza and watch it being put together before it’s slid into a hot, open-flame oven, where it’s cooked and ready to go in about three minutes.

• Photos: Pasadena pizza choices

Oven temperatures at these artisan-style pizza shops typically run as hot as 800 degrees.

“The hottest segment in the restaurant industry today is fast-casual, and within that segment fast-casual pizza is the biggest growth engine,” said Rick Wetzel, who co-founded Blaze Pizza along with his wife Elise. “It’s a $38 billion category and is second only to burgers.”

MORE: Review of Pasadena pizza restaurants

The Wetzels are no strangers to the fast food industry. In 1994 they launched Wetzel’s Pretzels at the South Bay Galleria in Redondo Beach. The chain now includes nearly 300 locations in the U.S., Puerto Rico, Canada, India, the Philippines, Lebanon and the Middle East.

Wetzel said the competition among fast-casual pizzerias is intense.

“The stakes are huge,” he said. “We discovered that there was a gaping hole in the pizza industry, and now a lot of people are piling into it. But we came in early with a lot of experience and we’re the biggest — we’ll do over $200 million in sales this year.”

Fast-casual pizza opening everywhere

Blaze opened about 109 restaurants in 2015 and the company plans to have 500 locations up and running by 2020, according to Wetzel.

Others are also planning to expand as business has been ramping up at all of the new pizzerias.

“We’re doing well,” said Carl Chang, founder and CEO of Pieology, which opened its Pasadena location at 345 S. Lake Ave. a year ago. “Pasadena is such a wonderful trade area and such a wonderful community for people who are food lovers.”

Pieology just got a boost from Andrew and Peggy Cherng, founders of Panda Restaurant Group. The Cherngs have invested in Pieology in the form of a minority ownership of the company.

“We’re not disclosing the full details, but Pieology will have access to many resources from Panda,” company spokeswoman Thien Ho said. “We can advise them on how to grow their operation and how to grow their culture on the development side.”

PizzaRev, which opened a Pasadena location at 3455 E. Foothill Blvd. in 2014, is also in an expansion mode.

“We have 29 locations now and we just moved into a national expansion via franchises,” said Nicholas Eckerman, the company’s co-founder, president and chief operating officer. “Our priority is not so much growth in sheer numbers, but opening the best restaurants in the best markets with the best franchises. Most of our stores in the Los Angeles area are corporate locations.”

Traditional Pizza Isn’t Going Away

This new wave of fast-casual pizza restaurants comes on top of an already full roster of pizzerias in Pasadena that includes Pizza Hut, Papa John’s Pizza, Round Table Pizza, Domino’s Pizza, Little Caesars Pizza, Nina’s Pizza Kitchen, Portofino’s Pizza and Settebello, among others. All told, there are now nearly 50 pizza locations in the city.

Is there room for all of these newcomers?

“I think there is,” Eckerman said. “Fast-casual is exciting to consumers because it’s such a departure from the traditional pizza industry. It’s really a departure from what existed. I think there is room for many brands in this space. This really reinvented the pizza space in a lot of people’s minds.”

Bret Thorn, senior food editor at the industry publication Nation’s Restaurant News, isn’t so sure about that.

“There are a lot of fast-casual concepts opening up all over the country, and I would be surprised if there was room for all of them,” he said. “There has to be a shakeout in the next couple of years. Some of these companies will go under.”

Fast casual may be the trend, but Joseph Hogan is clearly going the other way.

He launched his tiny, walk-up Pie Life Pizza shop at 691 S. Raymond Ave. in late October, and it quickly caught on.

“You can walk up and buy pizza by the slice or get a whole 18-inch pizza,” said Hogan, who is both the owner and chef at Pie Life. “We are traditional New York-style pizza. We make our dough fresh and in-house every day. It’s hand tossed and we also make our own sauce. It’s not delivered here. It’s the way they made pizza 200 years ago. It’s a bit of an art form.”

Ari Bailey, 29, of Pasadena, is a fan of New York-style pizza. And she’s noticed all the new “artisan” pizzerias have that opened in the city.

“It’s kind of strange how we have gourmet pizza all of the sudden,” she said. “You see it on every block or so.”

The latest edition to Pasadena’s ever-growing pizza community came on line last week when Two Guys From Italy opened up a location at 950 E. Colorado Blvd.

“We have another location in Glendale, but we’ve been getting a ton of orders from Pasadena, so we decided to come out here,” owner Jerry Rossi said. “We have lots of customers in Pasadena.”

So how would you like that pizza?

Pizza is one of those comfort foods that appeals to nearly everyone, and it comes in many variations. Here are some of them:

• Fast-casual pizza — This is the latest trend of thin-crust pizzas that are custom ordered and cooked in open-flame ovens at high temperatures.

• Chicago-style pizza — This pizza is distinguished by its thick, moist crust formed up the sides of a deep-dish pan and sauce as the last ingredient, added atop the cheese and toppings.

• New York-style pizza — This was originally developed in New York City by immigrants from Naples, Italy, where pizza was first created. It’s often sold in generously sized, thin and flexible slices and is traditionally hand-tossed, moderately topped with southern Italian-style Marinara sauce and liberally covered with cheese. The slices are sometimes eaten folded in half, as its size and flexibility may otherwise make it unwieldy to eat by hand.

• Sicilian pizza — This is typically a square pie with a thick crust. It is derived from Sfinciuni, a thick crust variety from Sicily, and was introduced in the U..S by early Sicilian immigrants.

• Hawaiian pizza — This has Canadian bacon, sliced ham, or bacon with pineapple toppings with mozzarella cheese. It’s especially popular in the western United States, but ironically not in Hawaii.

• Neapolitan pizza — A burning bell-shaped brick oven is required to create this style, and the pizzas often feature mozzarella cheese and fresh basil.