Following on from the Pip & Nut case study based in the UK market, here’s an entrepreneurial success story that originates in Ireland. Strong Roots
Leaving a family business is never easy. For Samuel Dennigan, it meant walking away from a third-generation fresh produce empire. It meant chasing a vision most people thought was foolish. Making frozen vegetables cool.
A decade later, that gamble has paid off spectacularly. In April 2024, McCain Foods completed its acquisition of Strong Roots. The Dublin-based plant-based frozen food company Dennigan founded in 2015. The deal followed McCain's initial investment of $55 million for a minority stake in 2021. It became one of the most significant exits for an Irish food startup in recent years.
But the path from family disappointment to international acquisition is an entrepreneurial. Masterclass. It demonstrates resilience strategic thinking, and the power of learning from failure.
The Art School Graduate Who Chose Potatoes
Dennigan's journey to food entrepreneurship was unconventional. After completing a diploma in art and design in Belfast, he earned a place at the prestigious National College of Art and Design in Dublin. But when he attended registration day, something didn't click.
He realised the art world wasn't going to provide the commercial self-sufficiency he wanted. So he turned down art school and joined the family business instead. He worked alongside his father and uncle for over a decade, absorbing every aspect of running a food business. From procurement and customer management to sales and supply chain logistics.
Despite this valuable education, Dennigan felt the pull to create something of his own. "It's a generational family business. I was the third generation, so it was a difficult conversation to have because you're expected to continue their legacy," Dennigan explained. "It was tough at the beginning, but I have understanding parents, and they eventually supported me."
The School of Hard Knocks: Two Failures First
What many don't realise is that Strong Roots wasn't his first attempt at building a food brand. It was actually his third. And the two previous ventures both failed.
The first was Sam's Potatoes. A line of microwaveable, ready-to-eat baby potatoes in steamer bags. Looking back, Dennigan describes it as a "me too" product rather than something innovative. The market didn't need another microwaveable potato offering.
The second failure was perhaps more painful. Dennigan licensed the Green Giant brand for fresh produce. He had ambitious plans to launch across major Irish retailers. But when launch time came, many retailers backed away. They viewed the brand as competition for their own private label products. The entire project collapsed.
Finding The Frozen Opportunity
By 2013, Dennigan started researching the frozen food category. What he discovered surprised him. Frozen vegetables were nutritionally comparable to fresh. Yet the category hadn't seen real innovation in decades. The market was dominated by basic vegetable medleys. Nobody was offering the "aspirational vegetables" that consumers were seeking out in fresh produce. Like beets, butternut squash, or sweet potato.
Crucially, frozen offered a two-year shelf life compared to fresh produce's few days. This created entirely different economic and distribution possibilities. The frozen category offered better margins and more innovation potential. It was a chance to build a brand with emotional resonance. It was a category ripe for disruption.
Building The Brand From Zero
With insights from previous failures, Dennigan spent two years setting up Strong Roots. He completed a start-your-own-business course and developed both the brand identity and recipes. He then secured bank backing with a major caveat: he had to pay it back within 90 days.
His initial bet was all or nothing: sell a single container of products worth €60,000. "If I didn't sell that then I would be broke and have to go back to my family with my tail between my legs to get a job back," he said. Thankfully, he sold it, and the business began its climb.
The Values That Made The Difference
Strong Roots was built on principles of sustainability, transparency, and environmental responsibility. The company became the first Irish plant-based food business awarded B Corp certification in 2020.
Strong Roots implemented sustainable agricultural practices throughout its supply chain. It added cardboard packaging to reduce plastic. It developed tools to measure and reduce carbon footprint. Dennigan faced pushback for these choices. "We were the first brand in Ireland to use the words 'plant-based' in an advertisement campaign and Ireland is the land of beef and dairy. We didn't get a lot of happy phone calls," he shared.
Breakthrough and Growth
The brand's first-ever listing was with Musgrave (owner of SuperValu and Centra). It initially launched through the SuperValu Food Academy. This was a programme designed to support small Irish food producers
The company’s first major listing in the UK market was with Waitrose in 2017. This served as its entry point into the British market. It was quickly followed by listings in other major supermarkets. Notably, Tesco, Sainsbury’s, and Morrisons
Strong Roots launched in the US in 2019, initially in around 3,000 stores. This expansion was bolstered by a £15 million private equity investment from Goode Partners. By September 2020, its products were in over 2,000 Walmart stores. Later it expanded to Whole Foods, Kroger, and others. The company established a US office in Manhattan to manage this growth. Sam Dennigan moved there to oversee operations.
The McCain Partnership and Acquisition
In December 2021, Strong Roots announced a strategic partnership with McCain Foods. The Canadian frozen food giant invested $55 million for a minority stake. McCain needed to diversify its portfolio. It wanted to meet evolving consumer demand for healthier, plant-based options. Strong Roots needed scale, manufacturing capacity, and international distribution networks.
Over three years, the partnership flourished. McCain helped Strong Roots expand globally and explore foodservice opportunities. In April 2024, McCain completed the acquisition. It brought the brand fully into the McCain family while maintaining its independence.
The brand continues to operate independently. Dennigan works alongside the team to drive portfolio innovation. The acquisition achieved what most entrepreneurs dream of. A successful exit that provides financial reward. While at the same time allowing the brand to grow, with significantly more resources.
Key Entrepreneurial Lessons
Dennigan's journey offers several crucial insights:
Failure is education, not defeat. His two failed ventures taught him what not to do. He treated them as valuable lessons that informed his third attempt.
Question industry assumptions. Dennigan's outsider perspective allowed him to ask questions that insiders never thought to ask. Sometimes the biggest opportunities lie in challenging what everyone else accepts as normal.
Sustainability can be a competitive advantage. Strong Roots' commitment to B Corp certification and environmental responsibility wasn't just marketing. It created genuine differentiation that drove business success.
Pick your battlefield carefully. Dennigan chose frozen over fresh because the category offered better margins. And a clearer path to building a global brand.
The right partner can accelerate everything. The McCain partnership provided capital, distribution, and expertise. It would have taken many more years to build the business independently.
Conclusion
Samuel Dennigan's story is a reminder that entrepreneurship is rarely a straight path. It's about learning from failures, challenging assumptions and staying true to your values
He journeyed from art school dropout to frozen food disruptor to McCain acquisition. Dennigan built Strong Roots by combining creative thinking with deep industry knowledge. Backed by genuine consumer insight and an unwavering commitment to sustainability. The two failed ventures weren't detours. They were essential preparation for the success that followed.
For aspiring entrepreneurs, the Strong Roots case study offers a roadmap. Find a category ripe for disruption. Build values into your business from day one. Learn from every failure, and don't be afraid to ask the stupid questions. Sometimes, an outsider who questions everything can see opportunities that industry veterans miss.