Teas that are destined to be sold loose are usually...

Teas that are destined to be sold loose are usually hand-picked, after which the whole leaves may be twisted or rolled. Teas destined for these tea bags are picked by machine. Credit: MCT

What's the difference between loose-leaf tea and the contents of the average supermarket tea bag?

Tea is nothing more or less than the leaves of the Camellia sinensis bush. For green tea, the leaves are processed (steamed or roasted) as soon as they are picked; for black tea, the leaves are left to oxidize (and darken) before being processed. (Chamomile, mint and rooibos are not true teas but rather infusions made from other plants.)

Connoisseurs prefer to buy tea leaves loose -- unbagged -- by the ounce. Such teas are usually identified by where they were grown and/or how they were processed. For example, Darjeeling and Assam are regions of India that lend their names to their famous black teas, ditto Keemun in China. Ceylon tea is from Sri Lanka, whose former name was Ceylon. Sencha is a green tea grown, in full sunlight, in Japan. Sencha leaves are picked in the spring and then steamed.

Teas that are destined to be sold loose are usually hand-picked, after which the whole leaves may be twisted or rolled: Gunpowder tea, from Zhejiang province in China, is rolled into little pellets said to resemble gunpowder. As with wine, tea "vintages" can vary in quality from year to year.

Linda Villano, owner of Manhasset-based SerendipiTea, sells what she calls loose "specialty tea" to both restaurants and consumers. The tea plant, she said, "is actually very hardy and will grow in any tropical climate as long as the soil is decent." But the finest teas are grown at high elevations in temperate zones. And whereas mass-market tea is harvested and processed by machine, "with specialty tea, everything is done by hand."

She explained that full-leaf tea "likes its space and needs to be steeped in a pot with plenty of water. That's the best way to bring out the nuances of the leaves."

Now, cut to the tea bag. Villano evinced a real admiration for "the big guys" such as Lipton, Tetley, Red Rose and PG tips, a leading U.K. brand. "The tasters who work for these companies are just amazing. They need to be constantly sourcing from all over the world and blending to get the same taste, year in and year out. Where the tea comes from will vary, but no matter where you are, tea from a Lipton tea bag will taste the same -- and probably tasted the same to your grandmother."

Teas destined for these tea bags, Villano explained, are picked by machine. The leaves are not whole but rather processed into bits called "fannings," which, because of their greater surface area, "brew up quicker and more robustly than loose leaves."

Not all tea bags are created equal. The lowest-quality bags are filled with so-called dust, "a fine powder that's a by-product of the other tea grades." (Translation: It's what they sweep up at the end of the day; think: tea scrapple.) Said Villano, "Buy a tea bag from a dollar store, break it open, and compare the tea to what's in a PG tips bag. I guarantee you the dollar-store bag will have more dust."

What about those new, fancy-pants pyramid tea bags?

They split the difference between loose and regular bagged tea. "There's more room than in a standard flat bag," Villano said, "so you can put whole leaves inside and there's room for them to expand a bit, flow a little more freely. You're getting a convenient cup of tea, closer to a proper steep."