In a November 2022 article on the National Institutes of Health (NIH) website titled “Coffee Rationing During World War II,” author Anne Rothfeld notes that in the United States, food rationing took a toll on civilians’ routine coffee consumption after the Office of Price Administration (OPA) implemented food rationing in the spring of 1942.

“The primary reason for wartime rationing was the equitable distribution of limited quantities of food to the American people,” Rothfeld writes. “A second reason was to rally support for the European war.”

As coffee rationing also was commonplace across Europe during World War II, Finland turned to the use of mushrooms to compensate. Inspired by Finland’s deep cultural connection with mushroom coffee, Four Sigmatic Founder Tero Isokauppila set out to launch the Original Mushroom Coffee in 2012.

“Raised on a 13th-generation Finnish family farm, Tero grew up foraging for mushrooms and drinking coffee — essential to Finnish culture, where coffee consumption is the highest per capita globally,” says a representative for Four Sigmatic, Venice, Calif. “Inspired by Finland’s WWII use of mushrooms as a coffee substitute, Tero created Four Sigmatic and the Original Mushroom Coffee. 

“Four Sigmatic is now a leading functional coffee with over 300 million cups sold,” they continue. “And Tero has written three bestselling books on mushrooms.”

Although today’s U.S. coffee market is booming, with the proliferation of mushroom coffee, Four Sigmatic is riding the wave of this functional beverage trend.

“According to the National Coffee Association, coffee is the No. 1 beverage consumed by adults in the U.S. with 73% of adults consuming coffee each week. Mushroom coffee, in particular, has been exploding over the past 10 years,” the brand representative says. “For Four Sigmatic, this is due to taste and efficacy. It tastes like a delicious cup of coffee but with added benefits of helping with focus, energy, and combating jitters and brain fog.”

Moreover, consumers of all demographics increasingly are turning to functional mushrooms as a solution to help them meet various needs states.

“These products help consumers with energy, focus, gut health, and immune and stress support,” the brand representative says. “By adding mushrooms to coffee, it makes it convenient for consumers to continue their daily routine and get the benefits they are looking for. Four Sigmatic uses certified organic, rigorously tested functional mushroom fruiting body extracts without filler grains or mycelium to deliver effective benefits in a delicious way.” 

Further, Four Sigmatic products are third-party tested for heavy metals, mycotoxins, molds, yeasts, irradiation, pesticides, and herbicides, it notes.

“Four Sigmatic stands behind offering the highest quality ingredients nature has to offer in a bioavailable, effective, simple, and delicious way,” the brand representative says.

Meeting consumer preferences

With a mission to share the healing powers of mushrooms with the world, Four Sigmatic has a variety of coffee products. As such, the brand understands the importance of variety, noting its new product offerings.

“Consumers have preferences when it comes to their coffee,” the brand representative notes. “These preferences lie in a variety of formats, flavors, roast levels, and even temperature (iced versus hot coffee). 

“Two new products that Four Sigmatic just launched in Whole Foods in mid-2025 include the new Focus Organic Half Caf Ground Coffee and new Focus Espresso Pods — the first functional espresso pod on the market,” they continue.

Currently distributed in more than 6,200 stores across the United States including Whole Foods, Sprouts, Target, Costco, and more, in addition, Four Sigmatic is available in Canada and the EU.

Looking forward, the brand plans to continue to further its retail, club, and international footprint across key retailers.

As far as the significance of using functional mushrooms, Four Sigmatic’s representative reiterates that mushrooms make for more effective coffee.

“Most people drink coffee to wake up, turn on their brain, and jump start their day,” they say. “Our best-selling product line, Focus Organic Coffee, adds a full functional dose of lion’s mane mushroom extract into every cup of coffee, a well-studied mushroom that has been used for centuries for its nootropic qualities of mental clarity, focus, and energy. Think of this like a honed-in version of your morning cup of joe, making it more effective for why you are sipping in the first place.”

Additionally, Four Sigmatic’s coffee products’ ease of use stand out.

“Functional mushroom benefits build over time,” the brand representative explains. “This means, in order to reap long-term focus and mental clarity; it’s key to use a product daily. 

“We understand how challenging it is for people to start new habits, especially those that include foreign mushrooms they may have never heard of,” they continue. “So, our strategy is to stack functions, adding a functional dose of these mushrooms into a habit that already exists for most of us, every day.”

Still, the bottom line for Four Sigmatic is delicious taste.

“Functional mushroom extracts are best utilized by the body when tasted,” the brand representative says. “Unfortunately, most of them taste bitter and are hard to get down on their own. What is the one bitter flavor the Western palate knows and loves? Coffee. 

“Four Sigmatic Focus Organic Coffee tastes like a delicious cup of Arabica coffee, and the flavor of the functional mushrooms is hidden seamlessly by the flavor of high-quality coffee. Essentially, it tastes like coffee, not like mushrooms,” they conclude.