Is there any more depressing scenario from modern office life than approaching the breakroom coffee pot and swirling the dregs in the glass carafe that have been scorching leftover java on the hot plate for three hours?
It’s the sickly sweet smell of generational ennui.
But for Maddie Cataldo and Maya Nefs, burnt coffee gives off the smell of success.
Cataldo and Nefs love their coffee so much they can’t bear to let any part of the coffee-making process go to waste. And they cherish environmental activism so much that they invented a product that reuses coffee’s biggest waste: The dry husks that flake off the intensely-flavored beans during the drying and roasting process.
Their business, Blazin’ Joe, compresses tons of those husks, mixes in a flammable but environmentally sound soy-based wax, and churns out a coffee brick as a campfire log or firestarter sticks. Not only are the former business school mates repurposing waste products, they argue, but they’re also helping people avoid the petroleum-chemical smells and residues of traditional paper-based artificial logs. (The molded sticks give off a pleasant toasted scent, but the smoke from burning is fairly neutral, and doesn’t taint the marshmallows.)
“We want to make an environmentally friendly product, and also one that’s a lot better alternative for your health than what’s out there,” Cataldo said.
They still have side gigs, but the pair are working tirelessly, with some help from Cataldo’s entrepreneurial father, to build Blazin’ Joe into a full-time, thriving business. Nefs picks up loads of spent bean husks from a couple of local roasters, and they process and package the bricks in her garage.
The industrial cauldron for melting the soy wax is a modified Crock Pot. The mixer is a drill with a long auger bit. A cousin made one of the brick molds with his 3-D printer.
And like all social media-savvy young businesses, they’ve now got some decent merch. They commissioned an art student friend to draw T-shirts with “Day of the Dead”-style skeletons enjoying their joe around, what else, a campfire. One hundred percent cotton, sustainable water-based ink, mailed in recycled polymer bags.
Their dedication to reuse and their high-energy, relatable approach are winning praise from circular economy advocates, who want to see more Colorado materials diverted from the waste stream and made into usable commodities.
“Colorado has become this hot spot, which is great,” said Laurie Johnson, co-founder and CEO of the nonprofit Circular Colorado recycling and reuse organization. Johnson cited policy changes like a producers’ packaging fee to support recycling expansion, and cities like Denver expanding composting to everyone. “We went from being at the tail end of recycling and sustainability, so it’s really fun to watch Colorado become a leader in circularity.”
Colorado’s overall waste diversion rate has lagged far behind the most successful states in recent years. Circular Colorado provides a development center to help businesses like Blazin’ Joe ramp up production and find markets, while NextCycle Colorado adds in pitch competitions and other entrepreneurial support.
Blazin’ Joe won NextCycle’s 2025 $5,000 grand prize in the pitch competition, beating out other worthy businesses like an electric vehicle battery recycler and a second-hand furniture distributor. Cataldo and Nefs now face the same kind of “chicken or the egg” challenges that test any growing small business, Johnson said.
They’ll need warehouse and production space to fulfill larger orders, as well as a steadier supply of coffee husks from cooperative roasters. But to secure that space and land investment capital for expansion, they’ll want to show solid orders and growing demand for the fire bricks, Johnson added.
“Then the people that want to buy it don’t want to wait that long for you to produce it. So it’s kind of managing that gap in the middle,” she said.
Blazin’ Joe praises the Ace Hardware group of stores for helping them secure valuable shelf space. The coffee logs retail at $27 for four campfire bricks and $9 for eight firestarters. Johnson said Colorado Ace stores have been a great partner to many sustainable business entrepreneurs.
Cataldo and Nefs met while playing hockey at CU Boulder, and were taking some of the same business classes. Cataldo used the burning-coffee idea as her business capstone project, and Nefs joined in. They tried using actual coffee grounds, post-drip, first. But drying out the grounds to the point they would make good fuel took too much energy to justify a sustainable business concept.
That’s when Cataldo’s father, who had developed and eventually sold a biodiesel sustainable fuel business, helped them work on the drier bean husks as the base fuel.
The pair are open about small business growing pains. Cataldo moved back home to Massachusetts, “to, well, to not be paying rent.” They’re using the two-state strategy to work on new markets, with Massachusetts and all of New England full of home fireplaces and frequent campers.
Where to focus the mail-order business is another puzzle. Everyone says “get on Amazon,” but they are studying which online retailers take what percentage cut of sales before jumping deeper into those markets.
Dropping new merch was a big development. In addition to the sustainable cotton and ink, Blazin’ Joe gives $2 per shirt to the Nature Conservancy, and $2 to the local artist, who was actually Cataldo’s first-year college roommate.
“We’re obviously not making enough to pay ourselves livable wages yet, but we’re not losing money on anything, and people seem happy with the price point,” Nefs said. “So it’s really just about bringing the major costs down. And we’ve got some ideas cooking.”
Cataldo said they are also buoyed by the gratification of infusing the business with their environmental ethos. They see the claims of other companies that claim to be “eco-friendly,” she said, and “we’re like, is it actually, or are you just throwing that out there?”
“One of my favorite parts about entrepreneurship is that we get to choose what we put out there,” Cataldo said, “and be the kind of business that we want to see when we’re shopping.”
