The balls—or bobas—were added to frosty drinks, juices, milk and tea and a myriad of other drinks, hot or iced. They provided an experience that Ho says is "not really eating a snack or drinking a drink." It's something of both.

A craving for the snack/drink has spread from Los Angeles, where a franchiser opened the first of what has grown to 85 Tapioca Express outlets to date. When Ho learned that her teenage daughters were traveling all the way from Saratoga High to an outlet in Cupertino on their half-hour lunch break just to buy what she thought of as an Asian black pearl drink, she wondered, "How can that be? They're American!" The clincher came when her 10-year-old son couldn't settle down to his homework until he could buy a strawberry "Snow Bubble," a smoothie-like drink made from milk.

"That did it," she relates with a laugh. "I said, 'Mom's going to open a Tapioca Express.'" She and Andy Chin, a software design engineer she knows through their day jobs, became partners in the store they opened on Big Basin Way in the old Madelaine's Bakery location. She says the tapioca teahouse idea is now almost as common as Starbucks. "I chose Saratoga for our store, because kids there don't have anyplace to hang out." Indeed, in the three months it has been open, students have discovered it.

"The icy passion fruit tapioca with the chewy little balls is really good," says Saratogan Jamie Urrutia, 15, who was spending a late Columbus Day morning in a lounging corner of the store with her sister Loren, 17, and friend Caroline Murphy, 15, of San Jose, all students at Pinewood School in Los Altos. The girls had discovered the teahouse the night before, prior to attending a concert at the HP Pavilion. "So we came back today."

One idea behind the store is to provide a comfortable place where there can be TV watching on a wide screen in the rear and Internet checking on two computers up front. The menu offers 129 flavored drinks made with Italian soda, fresh fruit, coffee, tea and milk to which tapioca balls may be added, or a variety of colorful jellies like coconut and "lemony"—all on display in a glass-encased cabinet. All are priced under $2.99. There also are typically Asian drinks, like hot ginger, longan and grass jelly ($2.50).

While "lunch" can be sipped through wide straws with a half-inch diameter, big enough to pass the black pearls, there also are dishes to enjoy with chopsticks, like crispy chicken ($3.25), fried calamari, potstickers, egg rolls, fish balls, string beans and toast. "We have Indian dishes with curry and Japanese with teriyaki," says Ho. "We plan to add California roll soon."

Tapioca is a starch that comes from the root of the cassava, or yuca, plant. It was probably first harvested by the Mayans in South America. While black and white pearls taste the same, the white have fewer calories, according to manager Jimmy Ho, Esther Ho's brother. They "provide the textural difference" in drinks. That means chewy.

Tapioca Express is located at 14441 Big Basin Way in Saratoga. It is open Sunday through Thursday from 10 a.m. until 11 p.m. and on Friday and Saturday from 10 a.m. until midnight. Call 408.741.8279.