IN 1520, explorer Ferdinand Magellan discovered a serpentine passage at the tip of South America that connected the Atlantic and Pacific oceans and thereby became the first person to lead an expedition across the mighty Pacific. In 1687, Isaac Newton published his Philosophiæ Naturalis Principia Mathematica, a supremely influential work in which he described his discovery of the law of gravity. In 1953, scientists Francis Crick and James Watson uncovered the "double helix" structure of DNA, the basic genetic material of all living things. 

And last week, I discovered Ku Day Ta in Milpitas, a tea lounge and cafe that serves a really good cup of chai.

Now, you may not think that finding a superb cup of spiced milk tea is on a par with those other discoveries, but if you're a chai drinker like me, yours is a life of constant disappointment and longing, and locating a source for good chai has a direct effect on one's quality of life.  

Coffee is king in America, and even though tea has made inroads, it's still a bit player. So while fresh-roasted, expertly brewed coffee is the norm, more often than not what passes for tea is a stale bag dunked in hot water. Baristas happily steam milk and pull espresso from gleaming machines, but they can't be bothered to steep some whole-leaf tea in properly heated water, a task that is far simpler than making a cappuccino. Not that I'm bitter about it or anything.

As for making chai, a process that involves simmering spices and tea in water and then adding milk, forget it. Most cafes make chai from concentrate and call it a day. The results are harshly spiced, oversweetened cups of badness. Worst of all is the vile, syrupy, hyperdulcet swill known as Oregon Chai, a chai concentrate that seems to dominate the market.

Ku Day Ta is quite different. The tea lounge gets its name from the phonetic pronunciation of "coup d'état," the toppling of a government by a small group of state insiders. Ku Day Ta owner Bee-Bee Liew sees herself as a tea-leaf insurgent.

"We want to revolutionize people's idea and conception of what tea is," she says. "I'm trying to bring tea up to the same level as wine."

Liew is a former Cisco programmer who decided to leave the corporate world and chart a new course. Her interest in health care led her to tea, a beverage high in antioxidants that give it a number of health benefits.

The tea lounge is in Milpitas' sprawling Great Mall, but the space offers a welcome respite from the shrill homogeneity of the shopping center. The red walls, low bench, stool seating and huge stone Buddha give the place an exotic, Southeast Asian vibe. As part of an event celebrating rooiboss tea, a fruity noncaffeinated tea from South Africa, the lounge is currently displaying a variety of African art and books. Ku Day Ta also offers a small menu of light snacks and sweets to go with the tea.

Liew was born in Malaysia, where chai is the caffeinated beverage of choice, so she knows her chai. Most cafes serve just one kind of chai, but Ku Day Ta offers 10, including those made with the traditional black tea as well as green. Sweet, plain or spicy, there's likely a chai here for you. They're a bit pricey, but you get what you pay for.

Liew and her staff make each cup of chai by hand. They measure out the tea and pound the spices with a mortar and pestle. The chai that won me over was the Kashmiri chai ($5.50). It's sweet, but just barely, and is made with fresh-ground cardamom and almond syrup. Masala chai ($4.50) is less sweet and overtly spiced than the Kashmiri chai and very good. While it was too subtle for me, the KDT chai ($5) is a simple chai made with fresh ginger and cardamom. It's the chai that Liew makes at home for herself.

I was a little dubious about green-tea chai, but my Pacific green latte ($5.50) converted me. It's made with beautiful, bright-lime-colored matcha green tea, soy milk and a bit of coconut milk. It's wonderfully creamy and lightly sweetened, and yet the flavor of the green tea shines through. For something a bit spicier, the Green Tiger chai ($4.75) is the way to go. It's like a green-tea version of the Kashmiri chai.

In addition to chai, Ku Day Ta carries a wide range of traditional oolong, green, black and rare teas as well a creative menu of iced teas. As she does with chai, Liew gets creative with iced tea. Made with fresh muddled mint, lime juice and matcha green tea, the Va Va Voom Mint ($5.50) tastes more like a cocktail than ice tea.

I loved the aromatic flavor of the lightly sweetened and refreshing lavender iced tea ($4.50), too. And for something as far removed from Lipton's as possible, the Summer Refresher ($5.50) combines matcha green tea, aloe vera and cucumber juice. The vegetal flavor is a bit odd at first, but it's cooling and thirst quenching and soon grew on me.

There's nothing else quite like Ku Day Ta in Silicon Valley. For tea lovers, it's like discovering a new world.