Historically considered a warm weather refreshment, iced tea has become an everyday beverage. It is one of the few flavorful cold beverages that tastes just as good unsweetened as it does sweet. It is also one of a handful of beverages associated with numerous health benefits, while being the only one that can deliver the benefits and be free of calories. It is no wonder why the ready-to-drink (R.-T.-D.) format is a booming business.

“The R.-T.-D. tea category is one of the fastest growing in the beverage industry,” said John Simmons founder and president, Third Street Inc., Louisville, Colo. “Sales continue to grow 7% annually, making it a $4.8 billion category. Within this category, the unsweetened R.-T.-D. teas are showing significant growth.”

According to The Nielsen Co., New York, the unsweetened R.-T.-D. iced tea category grew nearly 15% in sales in 2012 and 16% during the same period in 2013.

In the past five years, there have been more than 5,600 scientific studies on tea, forming a substantial body of research on the ubiquitous beverage. Among the findings is research indicating green tea and caffeine may trigger energy expenditure that may promote weight loss. Another study illustrates how tea may help counter the adverse effects of high-fat foods on blood vessels, which may reduce the risk of developing atherosclerosis, the most common cause of death in the United States.

“There is now an overwhelming body of research from around the world indicating that drinking tea can enhance human health,” said Jeffrey Blumberg, a professor at the Friedman School of Nutrition Science and Policy and director of the antioxidants research laboratory at the Jean Mayer U.S.D.A. Human Nutrition Research Center on Aging at Tufts University, Boston. “The many bioactive compounds in tea appear to impact virtually every cell in the body to help improve health outcomes … drinking at least a cup of green, black, white or oolong tea a day can contribute significantly to the promotion of public health.”

A brief history lesson

All “real” tea is made from leaves of the same evergreen plant: Camellia sinensis. The leaves are processed differently to achieve different flavor dimensions as well as varied levels of health and wellness benefits.

Traditional black tea undergoes a full fermentation step after the leaves have been picked. This is not a microbial fermentation but rather a series of reactions caused by the natural enzymes in the tea leaf that produce thousands of natural compounds. Oolong tea undergoes a partial fermentation, while green and white teas have almost no fermentation.

Herbal teas are not real tea as they are not derived from the C. sinensis plant. Within the tea industry, herbal teas are classified as tisanes.

Because tea plants are cultivated throughout the world, their environment and method of cultivation results in variations in flavor even with the same process. There are around 3,000 varieties of tea, but again, they all come from the same plant.

In the United States, more than three-fourths of all tea consumed is iced, which was invented by chance in 1904 at the Louisiana State Purchase Exposition in St. Louis. One day at the fair, the temperature was soaring and the staff in the Far East Tea House couldn’t get fair-goers to sample their hot tea. They decided to be creative and poured it over ice cubes, creating what soon became the exposition’s most popular beverage.

In addition to brewed tea being served hot and iced, both versions work well with the addition of flavors, juices, herbs and spices, as well as with or without sweetener, honey, milk, cream or lemon. Today, all of these product forms are being packaged and sold in an R.-T.-D. format, which appeals to the health and wellness consumer who is looking for better-for-you, on-the-go refreshment options.

This is apparent by the trend with formulations, including minimal to no sweetener, and when sweetener is added, it tends to be natural, such as a spoonful of honey or a dash of cane sugar. Sometimes sweetness is achieved through the addition of fruit flavors or concentrates, while there is growing interest in using stevia and monk fruit.

“We have discovered that agave, inulin and fructooligosaccharide each work synergistically with high-quality stevia to provide some natural sweetness to R.-T.-D. tea, resulting in significant calorie reduction,” said Adams Berzins, principal technologist for Ingredion, Westchester, Ill. “These ingredients are also a source of soluble fiber. Consumers who are attracted to R.-T.-D. tea for its healthfulness will likely be attracted to the perk of added fiber.”

Adding value to tea

Beverage manufacturers have many formulation options when it comes to producing R.-T.-D. tea, some more sophisticated than others. For example, Crystal Geyser Water Co., Calistoga, Calif., produces Tejava, a micro-brewed black tea made from tea leaves from the island of Java. For the best-tasting tea, only the top few leaves from each branch are picked, and only from May through October, the optimum harvesting months, according to the company. Tejava’s micro-brewing process eliminates bitterness and yields a rich, distinctive, full-bodied, unsweetened and calorie-free beverage.

Third Street just launched a premium line of fresh-brewed, R.-T.-D. teas exclusive to Whole Foods Market, Austin, Texas. Packaged in 1-liter bottles and selling for $2.49, it is the only R.-T.-D. tea line to carry U.S. Department of Agriculture-Organic, Fair Trade and Gluten-Free certifications, as well as being Non-G.M.O. Project Verified. Two flavors are available: unsweetened black tea and unsweetened green tea. Both teas are micro-brewed from tea leaves from the region of Nilgiri, India; no sweeteners are added to the zero-calorie blends.

Ito En North America Inc., New York, has added a new flavor to its Teas’ Tea Half & Half line. It is described as “superfruit acerola cherry meets the power of green tea.” The cherry variety originates from the Yucatan and is promoted as having 65 times the vitamin C content of an orange. The company said its green tea leaves are brewed to draw out from the tea leaves their naturally occurring antioxidants. Slightly sweetened with cane sugar and stevia, the acerola cherry flavor has 100 calories per 16.9-oz single-serve bottle.

Most recently the company introduced Teas’ Tea Lattes in two flavors: black tea and Matcha Light. The slightly sugar-sweetened shelf-stable lattes come in 16.9-oz plastic bottles. Made with nonfat milk, each single-serve bottle contains 80 calories and zero fat grams. The black tea latte is brewed with tea leaves from Sri Lanka. The fully oxidized tea leaf produces a full-bodied flavor. The Matcha latte is made with a powdered green tea traditionally used in Japanese tea ceremonies. Matcha is known for its herbaceous taste and naturally occurring antioxidants.

“We are excited to be expanding our bottled tea offerings with a new dimension by adding milk, a European tradition that dates back to the 17th century,” said Rona Tison, senior vice-president of corporate relations. “With consumers monitoring their calorie intake, our Teas’ Tea Lattes can be enjoyed guilt free without compromising the integrity of a pure tea taste.”

Mmm…Tea Co., Arlington Heights, Ill., recently entered the R.-T.-D. tea sector with a line of namesake single-serve bottles. Either unsweetened or containing honey, product labels boast the fact the beverages are kettle brewed and described as a “taste of simplicity.” A 12-oz glass bottle of the Unsweetened Green Tea & Hibiscus variety contains a real hibiscus flower for flavor. Back labels tout the fact that the beverage is made with real tea — no concentrates, no colors and no tea powders.

Many beverage manufacturers prefer to use concentrates or powders, as well as syrups or simple flavor extracts, as the ingredients are more economical and consistent than freshly brewed tea. Soluble or instant tea pre-mixes make it easy to bottle tea. The pre-mixes contain tea powders, often along with flavors such as lemon, peach or raspberry. Sometimes the sweetener may be part of the system for extra simplicity.

It is important that when oil-based flavors or other ingredients are part of an R.-T.-D. tea, that the ingredients be processed in a way that they remain in solution, as oil droplets floating in tea is highly undesirable.

“We have developed a high-efficiency emulsifier that is a naturally derived extract from the quillaja tree endemic to the country of Chile,” Mr. Berzins said. “It functions differently than standard emulsifiers used in the beverage industry in that it forms micelles to stabilize emulsions. This is accomplished by the active component in quillaja, the surfactact saponin. Because the saponin rapidly forms micelles around oil droplets once they are mixed together, the quillaja extract has the ability to emulsify higher oil loads without increasing the overall viscosity of the emulsion or contributing cloudiness.”

For consumers who prefer to customize their iced tea drinking experience, Nestle Waters North America, Stamford, Conn., recently introduced Nestea Liquid Water Enhancers. Made from tea leaves and natural flavors, the drops contain zero calories.

“We’re thrilled to bring to market a product that makes delicious tea enjoyment just a glass or bottle of water away,” said Sara Hilliard, senior marketing manager for Nestea. “Nestea Liquid Water Enhancers allow iced tea fans a way to get the refreshment they crave through this convenient, fun-to-use product.”

Three varieties — iced tea with lemon, iced tea with peach and half and half iced tea — are debuting in September exclusively to Target stores. Green tea citrus will join the lineup in November, at which time distribution will expand to convenience and grocery stores.

With health- and wellness-seeking consumers choosing R.-T.-D. tea over a soft drink or even fruit juice, they have most likely started noticing the quality and taste differences between mainstream brands and premium-positioned (and priced) products. There is room for growth in all R.-T.-D. tea types, with the future viewed as positive for specialty products.