(FORTUNE Small Business) – What at first looks like something right out of a Potions 101 class at the Hogwarts school is actually the beaker-, book-, and bottle-filled studio of scentmaker Mandy Aftel, in the lower level of her Berkeley home. "I'm a very organized mad scientist," says Aftel, who has turned the notion of branding on its nose by creating custom scents for individuals and companies. As with other luxury items, Aftel says, fragrance buyers "now want the highest quality and integrity of ingredients."

Since she started customizing in 2000, business owners have been seeking to have her help their companies make a distinctive olfactory impression. Customers include the owner of a lingerie business and a string of fashion models eager to start their own perfume lines, as well as a dentist and his wife, who own a spa. There was also a restaurateur who wanted the candles he used to exude a signature fragrance, and publisher Gibbs Smith from tiny Boulder, Utah, who sought a perfume that would mark the town. "She's a genius," says Smith.

Aftel, 56, was a practicing psychotherapist in 1993 when she took a class in perfume making. With a partner, she then started a line of perfumes called Grandiflorum, which was sold in high-end retailers. In 1998 she created Aftelier Perfumes, a natural line, and landed her first client, a woman who was looking for a custom fragrance for a line of massage oils.

A new customer starts the search for a distinctive fragrance by sitting with Aftel at what is known as her "perfumer's organ," a series of narrow-depth shelves that hold hundreds of bottles, grouped together by whether they serve as top notes (essential oils, such as black pepper), middle notes (say, jasmine or rose), or base notes (sandalwood, vanilla). These components are the building blocks of the fragrance, from the first hint to the characteristic wallop and then the lingering scent. Over the course of two hours the customer sniffs the bottle caps, chooses several favorites in each category, and finally ranks preferences. Aftel then starts blending different components in varying ratios. Weeks later, she mails out a sample. Her $700 fee includes creating as many as three versions of the fragrance. The client, after approving the final version, receives a quarter-ounce of liquid perfume and a quarter-ounce solid version of the same fragrance in a sterling-silver compact.

Business clients pay a $2,500 consultation fee and, unlike individuals, can buy the written formula, at a price that depends on its complexity. This year Aftel expects revenues of $250,000, up from $150,000 in 2003. How will she reinvest any profits? Well, she has been known to spend as much as $1,500 on one ounce of rare oil.

If your company were a fragrance, what would it smell like? Answering that question has become Mandy Aftel's business.