How a traditional Lucerne-based manufacturing company is reducing its maintenance costs and stabilizing its processes with modern water treatment technology.
On a crisp winter morning in central Switzerland, we find ourselves stepping into the warm, chocolate-scented world of Aeschbach Chocolatier. Upstairs, in a glass-walled meeting room overlooking the production floor, CEO Jürg Rogenmoser greets us with a broad smile and the jovial warmth of someone who treasures both people and chocolate. Behind him, through the windows, pralines glide along conveyor belts, confectioners shape truffles by hand, and the entire building hums with the quiet precision of Swiss craft at its finest.
Founded in 1972, Aeschbach has grown from a small family business into one of Switzerland’s most respected chocolatiers. More recently, the company won a national tender to supply pralines for SWISS International Air Lines – a milestone that has strengthened its reputation far beyond Central Switzerland. “Quality is a given,” says Rogenmoser, “but flexibility, innovation and sustainable packaging played a decisive role.”
Sustainability is not an afterthought here — it is stitched into the company’s identity. When Aeschbach moved to its current site in Root (Luzern), they deliberately designed their facility around fossil-free energy. A groundwater-based geothermal system provides heating and cooling; later, a solar PV installation was added across every available roof surface, covering almost half the company’s electricity needs year-round. “We produce nearly all of it ourselves,” says Rogenmoser proudly. “And because our systems run 24/7, the energy we generate is used immediately – almost nothing goes back into the grid.” The company’s sustainability ethos also extends across the entire value chain: sourcing cocoa through initiatives that support education and healthcare in producing regions, insisting on Swiss sugar and milk powder, working with regional suppliers, and promoting sustainable transport for employees. “It only works if you bring the customer along,” he adds. “People need to know that when they buy our chocolate, they are supporting these choices.”
But despite all this progress, one challenge remained – hidden beneath the surface, deep in the geothermal system that keeps the chocolate at perfect temperature. Soon after moving into the new building, the team began noticing declining performance in their heat exchangers. Flow rates dropped month after month, and the system’s efficiency fell dramatically. When technicians opened the plate heat exchangers, they found what Jürg describes as “richtiger roter Schlick” – a reddish sludge caused by iron bacteria.
This sludge restricted water flow and forced Aeschbach into an exhausting cycle: dismantling and cleaning the system three to four times a year, plus regularly cleaning both the extraction and return wells. “It was frustrating,” he admits. “You invest in a renewable energy system to avoid fossil fuels, but when the maintenance becomes so intensive, the benefits start to fade.”
The turning point came almost by chance: “One of our technicians said, ‘Jürg, you’re always complaining about the heat exchangers: why don’t you look at AQUA4D?’” Rogenmoser visited the website, reviewed case studies, and recognised exactly the same reddish deposits he saw in his own system. Within months, the decision was made: an AQUA4D system was installed in July 2025.
The results, even after only a few months, have been truly remarkable.
Before AQUA4D, the geothermal system always required cleaning after three to four months. With AQUA4D in operation, that threshold was never reached. “By October, I should have already needed the next cleaning, but there was no drop in flow rates,” explains Rogenmoser. For the first time since moving to Root, the system ran smoothly for more than half a year. Even when the exchangers were opened for inspection, they were in significantly better condition: less sludge, lighter colouration, and in one of the exchangers, so little fouling that the technician said he could simply have closed it again. “That was unheard of,” Rogenmoser says. The pleasant surprise was shared by the maintenance contractors normally tasked with power-cleaning – many hours of rather undesirable work.
The financial implications are equally compelling. Regular cleaning of heat exchangers and wells was costly, and not only in labour. Every decline in geothermal performance meant switching to electricity to supply heating or cooling demand. Aeschbach estimates that if AQUA4D merely halves the number of required cleanings, the system will pay for itself in under two years. If performance continues improving, the investment could amortise within a single year. “I’m optimistic,” he says. “If this continues, AQUA4D will make our geothermal system viable for many years to come.”
Beyond savings and sustainability, there is a human element as well: technicians, engineers and planners are following the results with curiosity. “Everyone involved is eager to see how this develops,” Rogenmoser notes. “There are many systems out there with the same problem. AQUA4D could help a lot of companies.” And would he recommend it? His answer is immediate: “Absolutely. I used to think we were the only ones with this issue, but I’ve learned it’s widespread. What we’ve seen so far is positive, and the technology fits perfectly with our philosophy. It’s simple, ecological, and lowmaintenance. I can fully recommend it with a good conscience.”
As we step back out into the cold winter air, the contrast with the warm, fragrant world inside Aeschbach could not be sharper. Yet the story here is one of alignment: Swiss craftsmanship, renewable energy, ethical sourcing, and now water efficiency – all working together to create a resilient future for one of Switzerland’s most beloved culinary arts. In a world where sustainability demands practical solutions, Aeschbach Chocolatier shows how innovation and tradition can blend as seamlessly as cocoa and milk. And AQUA4D, quietly installed in the background, is now part of that recipe.
Source: AQUA4D press release
