On a blustery evening last week, actress Sienna Miller — clad in a black bomber jacket and red leg warmers — ducked into Sabon on Spring Street. She walked purposefully toward the lotions, picked up a small tub of vanilla-coconut butter cream, paid, and walked out.
For the Sabon saleswomen, there was no time to be star-struck; there were too many other shoppers to help.

New York City has served as the American testing ground for Sabon, a Tel Aviv-based retailer of bath soaps that are made at an agricultural cooperative, or moshav, in northern Israel. Thanks to its success in the city, now home to six of its 12 stores stateside, executives at Sabon say there will be 100 retail locations in America within five years. As many as 25% of those stores will be in and around New York, a company spokeswoman, Lindy Cohen, said.

Sabon’s North American chief executive, Sharon Hasson, said he would open stores in the Herald Square and Union Square neighborhoods, and in Williamsburg, Brooklyn, as part of the expansion rollout. Additional locations on the Upper East and the Upper West sides, where there are already shops, are also likely, he said.

When Mr. Hasson in 2003 chose New York for Sabon’s first store outside Israel, he said he had trouble securing a lease. He said Manhattan landlords were skeptical that a business built around $6 bars of soap — sabon is Hebrew for soap — could generate enough money to honor the lease.

It’s not just soap that pays the rent. Sabon offers dozens of higher-priced products. A 6.7-ounce jar of lemon-basil “sorbet gel” lotion for example, retails for $22; while a 24-ounce bottle of patchouli-vanilla-lavender bath foam costs $25.

Sabon’s founders, Avi Piatok and Sigal Kotler-Levi, seeing the growing popularity of natural bath and body products from India, opened their first store in a trendy Tel Aviv district 10 years ago. They contracted a husband-and-wife team of soap makers, Edo and Deborah Solomon, to mix, mold, and chill olive- and coconut oil-based bars from their one-room apartment on Moshav Amikam.

Early on, Ms Kotler-Levi hand-painted the gift boxes. “Sometimes it’s hard to believe that it’s the same company — that I used to sit in my living room, painting and putting lavender in each box, one-by-one,” she said.

These days, Moshav Amikam boasts a soap factory that employs about 25 people, and the Solomons, well, “they live in a very big house,” Ms. Kotler-Levi, who no longer paints boxes or affixes labels, said.

Still, Sabon executives are trying to maintain a quaint atmosphere in each of its 50-plus stores worldwide. Shops are designed to look like boutiques — featuring stone fountains, dark-wood shelving, wrought iron furnishings, and dramatic chandeliers. Four-pound bars of candy-colored soaps, waiting to be cut into smaller bath bars, fill overhead shelves.

Most products are sold in thick glass bottles and jars with antique-style labels that appear handwritten, but are not.

“I might be a little addicted right now,” a 35-year-old Queens resident, Carmela Nicholson, said, noting she rarely goes a week without making a purchase at Sabon. “I don’t know if it’s the products or the packaging. Everything in here looks so much prettier than what you’d see in Duane Reade.”

Sabon could face competition from drugstores and supermarkets, as mass-market retailers try to cash in on the growing demand for handmade soaps, the president of the Handcrafted Soap Makers Guild, Marie Gale said. “Now you go to Wal-Mart and see what look like handcrafted soaps, but aren’t,” or soaps handcrafted en masse overseas, she said. “It’s hard to compete even with a better product.”