Crowdfunding hits W113m as sugar-free plum startup turns skeptics into believers

Founder swaps sugar for natural alternatives, runs 300-plus experiments to reinvent a Korean staple

Five Tumblbug campaigns raise 113.85 million won ($83,749); sales grow 154% in two years

50 tons of would-be discarded plums turned into marketable products

Oh Tae-geun, CEO of Robcall [provided by Robcall]

"Plums are supposed to be good for you — but do they really have to be pickled in sugar?"

That question sent Oh Tae-geun, 37, founder of Robcall, crisscrossing more than 8,400 kilometers of plum-growing regions across South Korea. He ran more than 300 experiments using premium-grade stevia and erythritol as natural sugar substitutes, determined to preserve the full flavor and health benefits of the fruit. The result was Maesil Maesil, a sugar-free, high-concentration plum stick.

The market response exceeded expectations. The product's first Tumblbug crowdfunding campaign drew 22.36 million won against a target of 1 million won ($736) — an achievement rate of 2,236 percent. Crowdfunding allows creators to present a product to consumers before its official launch and collect pledges toward a set funding goal.

Subsequent campaigns proved equally successful: a sugar-free plum tea in stick form raised 10.16 million won, a postbiotic probiotic jelly with 30 billion colony-forming units brought in 17.76 million won, and OMG — a sugar-free, caffeine-free omija berry drink — attracted 21.27 million won.

Maesil Maesil, a sugar-free plum tea in stick form [provided by Robcall]

Maesil Maesil alone raised 42.29 million won against a target of 500,000 won, an achievement rate of 8,457 percent. Across all five Tumblbug campaigns, cumulative pledges surpassed 113.85 million won.

The secret behind Oh's success turned out to be, surprisingly, a willingness to abandon the familiar.

He started by replacing the sugar that had always gone into traditional plum and omija syrups, substituting premium-grade stevia and erythritol instead. Maesil Maesil emerged as a zero-sugar product with 0 grams of sugar, while OMG contains just 1 gram — qualifying it as sugar-free under Korean labeling standards.

The products tapped directly into a growing consumer wariness about sugar and blood-sugar spikes.

Robcall's Tumblbug crowdfunding results (provided by Robcall):

The consumer enthusiasm validated in crowdfunding carried over into mainstream retail. Robcall products secured shelf space at Hyundai Department Store, Shinsegae Department Store and Muji, and sales climbed rapidly. Revenue grew from about 227 million won in 2023 to 577 million won in 2025 — more than doubling in two years.

Yet Oh does not measure success in revenue figures alone.

"The era when a good product sells itself is over," he said. "Consumers are drawn to stories, and they choose experiences, not just functions."

For Oh, building a brand means far more than designing a pretty logo or refreshing the packaging. It means engineering every experience around a product — whether customers can eat it without worrying about sugar, whether the design is appealing enough to sit on a desk, whether it fits easily into a bag.

Oh first discovered the potential of locally grown produce during his university years.

While studying advertising and public relations, he took a leave of absence and spent a year running a cafe in Buyeo, South Chungcheong Province, built around local specialty ingredients. The experience taught him that the same agricultural product could become something entirely different depending on how it was framed and packaged.

After graduating, he worked as a marketer at a food and beverage brand and a media-commerce inner-beauty brand. A campaign promoting tea made from pumpkins grown in Haenam, South Jeolla Province, reinforced the lesson.

Even the finest raw ingredients went unnoticed if they could not be communicated to consumers effectively. Conversely, an ordinary-looking crop could open an entirely new market, given the right story and the right product concept.

Those hands-on experiences became the foundation for Oh's decision, after launching Robcall, to focus on brand-building rather than simply selling farm produce. His core conviction: good raw materials are already abundant across the country, but what matters is giving consumers a reason to choose a particular product.

That conviction shaped his go-to-market strategy. Rather than running advertising campaigns straight after launch, he chose to submit each product to the unsparing verdict of crowdfunding first.

"I wanted to make a product that customers would recognize before I spent money on advertising," he said. "Whether consumers would open their wallets was the most objective measure of all." The process was a test of whether a product could genuinely win in the market — whether it was compelling enough for people to pay for it with their own money.

Robcall products on display at House of Shinsegae Cheongdam in Cheongdam-dong, Gangnam-gu, Seoul. [provided by Robcall]

The success with plums became a springboard for expanding into other local crops — omija berries, yuzu, black garlic and more. After launching OMG, the sugar-free, caffeine-free omija drink, and then the postbiotic probiotic jelly, Oh reflected that the results had confirmed something bigger than any single ingredient. "It wasn't that plums were special," he said. "What worked was the method itself — turning local farm produce into a brand."

Today Oh operates less as a manufacturer and more as a brand strategist unearthing hidden value in underused crops. Beyond plums and omija, he is exploring shine muscat, black garlic, yuzu and hardy kiwi — produce that has yet to receive the recognition it deserves.

Asked what achievement he is most proud of, Oh did not mention revenue. "Fifty tons," he said. That is the total weight of plums he has transformed into marketable products.

About 860 tons of plums are discarded in South Korea every year, he said, because they cannot find buyers or fail to meet size and quality standards. Rescuing 50 tons of that would-be waste and turning it into products consumers actually buy is, for him, the most meaningful milestone. "For farmers, unsold produce with nowhere to go is the biggest headache," he said. "When a brand exists, farm produce finds more uses, and that ultimately creates a virtuous cycle that feeds back into farm income."

Postbiotic probiotic jelly with 30 billion colony-forming units [provided by Robcall]

For Oh, a brand is ultimately a bridge between farmers and consumers.

The road to his current success was anything but smooth. He made hundreds of prototypes in a small workshop, and when flavors shifted subtly during scale-up to mass production, he scrapped the research and started over. Coordinating with contract manufacturers brought its own share of trial and error. To finish each product, he learned the production process himself, drilling down into everything from ingredient ratios to manufacturing steps.

The long, stubborn process ultimately built the kind of deep consumer trust that a brand needs to last. More than anything, it was the customers who waited for the products and cheered him on that kept him going.

Government support also provided a solid footing along the way. Startup programs — including a pre-startup package and a youth entrepreneurship academy — helped him lay the groundwork for product development, and backing from the Korea Agency of Education, Promotion and Information Service in Food, Agriculture, Forestry and Fisheries enabled him to pursue exports to France. He is now preparing to enter the United States and Singapore markets.

Oh recalled that early government support meant more than just funding. "It helped me cut down significantly on trial and error while turning an idea into an actual product," he said, "and it gave me a platform to take on overseas markets."

His vision for the future of agriculture flows from the same conviction.

He argued that the future of farming lies not simply in growing crops well, but in turning their value into brands that consumers can choose.

Maesil Maesil jelly [provided by Robcall]

"The skills needed to grow good produce and the skills needed to build a good brand are completely different," he said. "We now need people who can connect the two and create synergy."

Oh also advises young entrepreneurs to ease off the urge to succeed quickly. A brand cannot be built overnight, he says. It takes at least two to three years of building genuine trust with consumers, and staying power comes from earning real customer feedback before chasing immediate sales.

His revenue target for this year is 1 billion won.

Oh's sights are already set beyond the domestic market. He is moving quickly to enter Singapore and North America through Amazon, leading with a health and beauty positioning, and plans to launch a new black garlic product in October.

Looking further ahead, he plans to build a system for monitoring at-risk farm produce through a research and development program under the TIPS (Tech Incubator Program for Startup) scheme, linked to private investment-led technology startup support in 2026.

Oh Tae-geun (right), CEO of Robcall, speaks with local media at a pop-up store during the K-Plus Festival held in the 13th arrondissement of Paris, France, on May 16 last year. Robcall showcased Maesil Maesil and OMG at the event, conducting product validation and sales targeting local consumers. [provided by Robcall]

His ultimate goal is to build a self-reinforcing "Robcall flywheel" — modeled on the kind of virtuous cycles that Amazon and Tesla have built — in which upcycling local farm produce continuously generates new production and consumption.

It started with plums, but the ambition runs far deeper. His next challenge is to grow a global K-wellness brand from underappreciated local crops — shine muscat, black garlic, yuzu and hardy kiwi — and take them to markets around the world.

"There are so many local farm products in this country that have never found the right brand," he said. "My ultimate dream is to create a healthy, self-sustaining cycle in which more and more of those products are reborn with new value and translate directly into reliable income for farming households."

A promotional image for the series on young farmers earning over 100 million won a year

adastra@heraldcorp.com