43-year-old spent $5,000 to start a business in her NYC apartment kitchen—now it brings in $147 million a year

Elizabeth Stein was bothered by her sweet tooth.

Stein, a nutritionist, couldn't find sweets on grocery shelves that she was comfortable recommending to clients — everything was too unhealthy. So in 2008, she decided to create her own, selling muffin mixes at a local triathlon as a side hustle to help promote her business.

The side hustle overtook her full-time job: Today, Stein is the CEO of Purely Elizabeth, a Boulder, Colorado-based natural foods company that brought in $147 million in sales last year, according to documents reviewed by CNBC Make It. The 50-employee company's sales have grown almost every year since its launch, and it reached profitability in 2023, a spokesperson says.

Purely Elizabeth is now most well-known for its granola, made with so-called "superfoods" — amaranth, quinoa, chia seeds — and sweetened with organic coconut sugar. Its granolas, cereals and oatmeal are shelved in roughly 30,000 grocery stores across the U.S., including Kroger, Albertsons, Whole Foods and Walmart.

The business helped popularize a "healthy granola" market in the U.S., alongside competitor brands like Kind Snacks and Bear Naked. They all contribute to the global granola industry, which was worth $3.7 billion as recently as 2023, according to a Future Market Insights report published last year.

Here's how Stein went from making muffin mixes in her New York apartment's kitchen to building one of the country's predominant granola brands.

Shipping muffin mixes from a New York apartment

As an early-career marketing professional, Stein competed in marathons and triathlons on the side — sparking her interest in health and wellness, she says. She decided on a career change, attending the Institute of Integrative Nutrition in 2007 and becoming a full-time nutrition counselor the following year, also teaching cooking classes on the side.

She promoted her business at races. One day, she brought a batch of blueberry muffins filled with ingredients like chia seeds, coconut sugar and quinoa.

"Person after person kept asking where they could find these delicious muffins outside of the race," says Stein, 43. "So I sort of pivoted on the spot, and I told people that ... when they sign up for my nutrition newsletter, I'd let them know where and when the products will be available."

A few months later, Stein built a website for the muffin mix. She was featured in an email newsletter called DailyCandy, and "had about $10,000 of orders in three hours," she says. "That was really how the business was born."

Stein made Purely Elizabeth her full-time job. She spent $5,000 on muffin and pancake mix ingredients, and shipped online orders from her apartment in New York's Upper West Side neighborhood, using her hallway as an office, she says. When the business outgrew her kitchen's capacity, she worked with a commercial kitchen in Philadelphia.

Slowly, Stein got Purely Elizabeth onto the shelves of a few brick-and-mortar stores in New York and Philadelphia, she says — before her mom landed a much bigger sales victory. "My mom, I will say, was the best salesperson," says Stein. "She single handedly got us into about 40 stores in the Whole Foods Mid-Atlantic region by calling up each of the buyers on the phone."

'This is the best granola I've ever had'

In 2011, Stein made a batch of granola while experimenting with new ingredients. "[My mom] tasted it and said, 'This is the best granola I've ever had. This should be your next product,'" Stein says. "It became very clear very quickly that the granola was far more delicious than the muffin mixes were."

Stein replaced the mixes with the granola and hired her first two employees. In 2013, Purely Elizabeth reached $2 million in annual revenue — up from $200,000 in 2011 — and Stein received a life-changing email, she says.

"I got an email from Whole Foods Global, and the email said, 'We are pushing you out nationally,'" says Stein. "I remember just starting to hysterically cry on the subway, having this feeling, this gut feeling that this was about to fully change the trajectory of the business."

In 2014, Stein moved herself and her business to Boulder — partially to be closer to a Purely Elizabeth manufacturer, and partially so she could "have a little bit more balance in my life ... walk out of my house, go hiking in the morning," she says.

As Purely Elizabeth grew, it attracted new challenges. For example, Stein says: "How do we stay true [to the company's original health-focused goal] from a sourcing perspective? There's only a finite amount of certain ingredients. That's something that we really need to consider."

Competition is also a factor, says Sucharita Kodali, a vice president and principal analyst at market research firm Forrester. "It's a super competitive landscape for packaged goods, and it's really easy to get kicked off of a shelf," Kodali says. "There is no patent on 'healthy' or 'organic.'"

Stein intends to face those obstacles head-on, she says.

"This is my baby," says Stein. "I want to stay CEO of Purely Elizabeth and [continue] to build this platform, build this lifestyle brand and continue to see where the brand can go."