Using ketchup to dip or slather french fries is a long-established American tradition. The pairing has not only provided consumers with a distinct flavor, but it has given diners the ability to choose how much of the condiment to use, based on their own tastes.

It turns out that this flavor-control ritual also served as the restaurant industry’s foreshadowing of a much larger concept—individualization—that has been sweeping across the industrial world for the past couple of decades.

Restaurants are increasingly using various sauces and dips to provide customers with the ability to construct their own flavor profiles built around existing menu items. This notion is viewed as one aspect of a process that experts have dubbed “mass customization.”

“The idea is that you can create customized products for a large number of customers without a large incremental increase in cost or delivery time,” says Dennis Lombardi, executive vice president at WD Partners, a Columbus, Ohio–based retail design firm.

Mass customization allows customers to be involved in making decisions regarding the design of an end product, often by using technology or flexible manufacturing processes. “This can translate to restaurants just as easily as a manufacturing plant,” Lombardi says.

Some products created through mass customization have thousands, even millions, of permutations, says B. Joseph Pine II, a Minnesota-based partner at the consulting firm Strategic Horizons and an author who has written extensively about the topic.

Customers had few options in mass-produced goods until the 1980s, when Michael Dell pioneered the idea of selling individually customized computers directly to buyers.

“Now, thousands of companies mass customize,” Pine says, “and quick-service restaurant companies are among them.”

One early example was Burger King, whose “Have It Your Way” campaign was used to differentiate itself from McDonald’s, the biggest mass burger operator at the time.

Since then, many quick-service restaurant operators, including McDonald’s, have taken pages, or even chapters, from the mass-customization playbook. In particular, they are using dips and sauces as a relatively inexpensive way to give customers more choices.

In fact, McDonald’s was at the forefront of a major advance in using multiple sauces to provide consumers with more control over their menu items.

In the late 1970s, then-company chef Rene Arend was looking for ways to provide consumers with wider choices as a change of pace. He came up with the idea of fried chicken nuggets with dipping sauce.

Arend tried more than 100 sauce ideas until barbecue, sweet and sour, and hot mustard sauces were selected. The product, Chicken McNuggets, and its dips in prepackaged cups, went into tests in 1979 and were added to the national menu in 1983.

Mass customization is so pervasive in today’s industry that choice is almost a business requisite, particularly among younger customers.

“Generation Y is the customize-me generation,” says Kara Nielsen, trendologist with the Center for Culinary Development in San Francisco. “Just as they can decide the look of their iPod or sneakers, they want to customize their food.”

Sauces and dips provide a smart way to do that, “especially in the quick-service world,” she says. It also allows friends to share menu items but still get their own desired flavors.

Customization may be in the DNA of the Millennials because they came of age during the turn of the century, but having options in terms of sauces and dips is seen as a plus by most consumers, no matter the age.

“Older consumers are looking at these sauces and dip possibilities as increments, while Millennials see this as a … point of entry,” says Kim Cupelli, assistant director of Group 57, the customized culinary solution team at Heinz Corp. in Pittsburgh.

Dips and sauces provide consumers with a low-risk, low-cost way to try something new or different, particularly with bold or spicy flavors.

“If you’re ordering something from the menu, and there’s an unusual dipping sauce, you can try it without investing too much in it,” says Sara Monnette, senior manager for consumer and market research at Technomic, a food industry consulting and research firm.

“Increasingly, consumers have the ability to try a dip or sauce and then decide how much is right for them,” she says.

With restaurants fighting for every consumer dollar, a great core product is important, “but sauces are the key if you want to drive traffic and craving,” Cupelli says. As a result, the past 18 months have seen a big increase in LTOs and new products with featured sauces.

One example is Wendy’s boneless wings, which use high-quality chicken with different flavored sauces. The current lineup includes Honey Barbecue, Sweet and Spicy Asian, and recently introduced Spicy Chipotle.

“One of the ways of keeping the product fresh is by adding a new sauce, which adds a unique flavor,” says Denny Lynch, senior vice president of communications at Wendy’s. The company typically works for months with its suppliers to research and develop its sauce recipes.

Wendy’s also features boneless chicken nuggets with several dipping sauces.

Rolling out a new sauce is a fairly inexpensive way to create additional taste profiles, unless the new flavor fizzles. “That’s why research and testing are so important,” Lynch says. “You don’t want to be left with a lot of product on your hands.”

Some restaurants serve wings with more than a half- dozen flavored sauces, and they also feature a number of dips, mostly ranch or blue cheese dressing, that allow customers to further customize their food.

Chicken tenders, strips, and fingers are also popular dipping foods, and the number of dips available varies dramatically among brands.

In fact, chicken is the most popular core product for sauces and dips at quick-service and fast-casual restaurants. The Foodservice Research Institute’s MenuMine, which tracks menu items from more than 625 restaurant chains, found that chicken was at the heart of six of the top 10 fast-feeder menu items that feature sauces or dips.

Joe Brady, the Foodservice Research Institute’s managing director, says the use of a batter or breading is a major factor in the use of a dipping sauce, and chicken just works best. Very few restaurants use breading or batter with beef or pork, although some do with seafood.

“I would suspect that the temperature contrast between cool dipping sauce and hot, deep-fried food is appreciated by today’s diner,” Brady says. And the breaded products’ texture absorbs more sauce.

Shane’s Rib Shack lets customers choose among 12 sauces for chicken wings and tenders, and it also has four sauces for its barbecued ribs, pork, and chicken.

“Sauce can make or break a restaurant,” says Shane Thompson, the company’s founder. “It’s amazing to see how sauces can change the taste profile of food items.”

Atlanta-based Shane’s has even taken customers’ advice on flavors and had them vote on potential new sauces. At least two sauces were created that way.

Sauce is certainly important to barbecue aficionados.

“In Texas, how many ways can you make smoked brisket or ribs?” asks Chef Bryant Currie, program chair for the Dallas campus of Career Education Corp.’s Le Cordon Bleu College of Culinary Arts. “You have different woods for smoke flavor and different rubs and mixes, but what sets your flavor profile apart is to be creative with sauces.”

Sauces have played a valuable role in cuisine for centuries. In the classical brigade-style kitchen, modernized by noted French chef Auguste Escoffier, the saucier is third in rank behind only the chef de cuisine and sous chef.

Modern sauces have their roots in the classics, Currie says. Even mayonnaise, which we call a dressing, is classically considered a sauce. Mustard goes back to Roman times, and American ketchup was once dubbed a “table sauce.”

These days, sauces provide restaurants with “an easy way to customize a flavor profile to a customer’s specific tastes without a whole lot of changes to the restaurant’s preparation process,” Lombardi says. “It also provides a sense of variety to the menu.”

Some brands are seeing so much opportunity with special sauces, that they’re working with vendors to create their own line of dips and marinades. “Restaurant-branded condiments have a much lower purchase price and can significantly lower the operator’s food costs, especially in high-volume restaurants,” says David Halt, director of foodservice sales for Red Gold, which creates specialized sauces for foodservice brands. “Chains that have made the switch to their own branded condiments have discovered a totally new way to differentiate their brand from their competition.”

The growing interest in international and ethnic cuisine—thanks to media, immigration, and the ease of international travel—combined with bold, ethnic cooking by creative chefs bring many more sauces and dips to the attention of consumers.

None has gained mass appeal more than salsa, which translates to sauce.

“Every culture has specific condiments that compliment the food,” Currie says. “In Mexico, much of the culture is built around fresh vegetables, such as tomatillos and jalapeños, so that became part of the salsa.”

Salsa moved beyond its Latino roots to surpass ketchup as America’s favorite condiment years ago. However, that may be an unfair comparison, because there are so many types and styles of salsas, depending not only on nationalities but regions.

Most Mexican and Southwestern restaurants feature salsas as either a topping or dip. At Chipotle, for instance, diners may choose one or more of four salsas to put on their burritos or as a dip with chips. Other restaurants feature multiple condiments in salsa bars, which Lombardi calls the “granddaddy of restaurant customization.”

The salsa bar has become an integral part of the dining experience at Moe’s Southwest Grill. The chain’s 400-plus restaurants feature three permanent salsas—fire-roasted pepper, chunky tomato and onion, and tomatillo with cilantro and jalapeño—along with a salsa that rotates in every six months.

“People are more educated on flavor profiles than they ever have been, and they know exactly what they want,” says Dan Barash, director of research and development for Atlanta-based Moe’s. “We’ve even seen people take cups of the roasted corn pico de gallo from the salsa bar to the cooking line and ask for it to be put in their burrito.”

Similarly, Asian sauces have lent themselves to customization, a tradition that continues at companies such as Pei Wei, a Scottsdale, Arizona–based fast-casual chain whose more than 150 restaurants focus on foods of various southeast Asian cultures.

The company has a variety of sauces, but they are not added until each dish is cooked, says Eric Justice, the chain’s director of culinary operations. As a result, customers can request extra or less sauce, as well as fewer or no spices, garlic, or other flavorings.

“I spend a lot of time on the line, and I bet about a third of the people do some sort of customization,” Justice says.

Asian influences are also important to sauces at Phillips Seafood Restaurants. Although traditional mayonnaise-based tartar sauce is served with the company’s crab cakes, the company looked to the Far East for inspiration for its newest condiment, Pineapple Sweet Chili Sauce, as a dipping sauce for spring rolls and calamari.

“It goes well across different proteins, so we expect customers will use the new sauce with shrimp, chicken, and pork as well,” says the Baltimore company’s executive chef, Dennis Gavagan. “The chili paste in the sauce is traditional, and I thought the pineapple was a natural fit, sweet but unique to the industry.”

International flavors are cutting across regional and national themes. One chain, Boston Market, is testing a salsa bar in several markets that feature not only Mexican flavors, but Mediterranean and South American ones as well.

This explosion of sauces also had an affect on that old favorite, french fries and ketchup. A number of quick serves have popped up featuring Belgian frites (fries originally were from Belgium, not France) with a wide range of dipping sauces.

At fRedhots and Fries in Glenview, Illinois, owner Fred Markoff makes fresh-cut fries with a choice of garlic, wasabi, chipotle, spicy aioli, artichoke, pesto, and Filipino red banana pepper dips; and one daily special flavor.

Markoff, a restaurant veteran, also created a long list of dips. For instance, one day when he used Jamaican spice for jerking pork, he also whipped up a jerk aioli.

Fries are served in cones and come with at least two dipping sauces. Customers who take more are charged 50 cents for each extra one.

Although fRedhots serves sandwiches, burgers, and hot dogs, more than 95 percent of customers get fries. He considers it a challenge to get customers to try new sauces.

“The house rule is take a sauce,” he says. “Most people thank us for that.”