The Water You’re Brewing With Is Probably Holding Your Coffee Back
Photo by Nicolas Ruiz
How Apax founder Simon Gautherin is quietly redefining coffee quality—one drop at a time
By Jana Kettner
I’ve always been upfront about being a work in progress. I don’t pretend to have all the answers—I ask questions. And lately, one hunch has kept tugging at me: Is water the most underrated part of brewing coffee?
It started after a visit to Jibbi’s Coffee Roasters in Sydney, where I tried a filter coffee prepared with a few drops of Apax, a concentrated mineral solution developed by Simon Gautherin. Same beans, same recipe—but the flavour was transformed. Brighter, juicier, more defined.
What followed was a conversation that challenged many of the fundamentals I thought I understood. Simon speaks not as a self-styled guru but as a builder—someone with a chemistry background, a taste for precision, and a belief that better coffee doesn’t need to be more complicated.
What’s surprising isn’t just how water works in coffee—it’s how little we’ve understood it all along.
Simon Gautherin at the Central Region Championship, where he earned 2nd place.
A Shift in the Cup
Simon started his career in strategy consulting. Coffee was a hobby, then a fascination, and finally, something he couldn’t stop digging into. “I moved to Sydney from Paris in 2016,” he told me, “and the tap water just tasted better. Brewing the same coffee, it was obvious: the water was changing everything.”
When a friend asked him to coach for a coffee competition, Simon saw an opening. Drawing on chemistry classes from years earlier, he began formulating his own brewing water using raw mineral salts: magnesium chloride, sodium chloride, bicarbonate. “I realized that every tiny tweak—changing calcium-to-magnesium ratio, adjusting the buffer—drastically shifted the flavour of the coffee. It was like having a new instrument to play with.”
One of those early breakthrough moments came while brewing a Geisha from Hacienda La Esmeralda alongside Carlos Escobar. “We changed just the water, and the flavour flipped—from jasmine and apricot to hibiscus and strawberry. Same coffee, completely different profile. That was the moment it really clicked.”
Fast forward to last week at the 2025 World Coffee Championship, and Carlos is once again part of a story that proves how powerful water can be. With Simon as part of his team, Carlos delivered an inspiring and technically masterful routine—earning third place in the world. And a quiet but crucial part of that achievement? Apax Drops.
Even more striking? According to Carlos himself, 8 out of 9 finalists in this year’s competition used Apax Lab Drops in their water.
This isn’t just a trend. It’s a signal that water—once ignored—is now seen as a tool of the highest precision, even at the pinnacle of competitive brewing.
Carlos Escobar and Simon Gautherin during World Coffee Championship, Jakarta 2025.
Breaking the Rules of Extraction
One of the most striking things Simon shared was how common narratives about water in coffee are... wrong.
“In most specialty training, we’re taught that minerals help extract coffee better,” he said. “But that’s not really what’s happening. What minerals actually do is influence how you perceive the coffee—its sweetness, acidity, body.”
Magnesium, for instance, adds structure and enhances fruitiness. Calcium softens texture. Bicarbonate controls acidity, but too much and the coffee falls flat. “It’s less about extraction chemistry, and more about sensory tuning,” Simon explained. “Think of it like applying a filter to a photo. The minerals don’t change the content—but they do change how you experience it.”
“We’ve misunderstood water for so long. It’s not just about extraction—it’s about how we experience coffee.”
This insight was a turning point. It pushed Simon to develop not just custom water profiles, but tools that allowed anyone—home brewer or world champion—to manipulate flavour after brewing.
The Apax Approach
Apax Lab wasn’t meant to be a business. It started as a favour. “I made water for a few barista friends competing nationally. They started winning. Then more people asked.” Shipping full bottles of water from Australia wasn’t sustainable, so Simon concentrated the formulas—just add distilled water and go.
By 2024, Apax had reached 50 countries, with over 120 national champions and two world champions using the product. The most recent evolution: Apax Drops, precise mineral blends in dropper bottles, allowing brewers to not only create ideal brewing water but also fine-tune the final cup—drop by drop.
Apax Lab Drops
“There’s something magical about it,” Simon said. “You brew a cup, take a sip, and then add one or two drops. Suddenly, it changes—more fruit, more texture. You’re literally seasoning your coffee. And the motion itself feels a bit like alchemy.”
The comparison is fitting. Apax doesn’t just offer mineral blends—it offers a framework for thinking about water as a sensory tool, not a fixed variable.
“You can buy the best beans in the world—but if your water is off, your coffee will be too.”
Why Good Coffee Still Tastes Bad
For Simon, one of the biggest problems in specialty coffee is how many people invest in beans and equipment—but ignore their water. “You can spend $100 on a bag of rare microlot coffee,” he said, “but if your water has 350 ppm of bicarbonate, it’s going to taste dull. You’re not tasting what that coffee actually is.”
His advice? Start with demineralized water—ZeroWater filters or supermarket distilled—and add minerals yourself. “That’s the simplest way to take control,” he said. “And it’s far more impactful than upgrading your kettle or V60.”
And if you can’t commit to a full system? Just taste. “Brewing should always be: taste, adjust, repeat,” Simon said. “It’s not about perfect numbers. It’s about what brings out the best in the coffee in front of you.”
The Future of Water in Coffee
Simon isn’t stopping at the café counter. He’s now working directly with producers at origin to help them cup their coffees with high-quality water. “It’s critical,” he said. “Producers should be able to taste their own coffee at its full potential. Bad water hides defects, yes—but it also hides brilliance.”
Photo by Delightin Dee
He’s also running experiments on how water impacts processing, not just brewing—particularly in washed coffees. “We’re looking at how different mineral compositions influence fermentation and cup clarity. It’s early, but promising.”
Long-term, Simon sees applications for Apax-style seasoning in wine, cocktails, even food. “Minerals are going to have a moment,” he said. “Not as gimmicks, but as tools for expression.”
“Water doesn’t just carry flavour. It shapes it. And the sooner we treat it like an ingredient—not just a medium—the better our coffee will be.”
So Why Aren’t We All Doing This?
When I asked him if people resist the idea of “adding minerals” to their coffee, he smiled. “Five years ago? Absolutely. But today? The timing is right. Brewers are more curious, more open. We’ve been lucky to catch that wave.”
For someone like me—curious but unpretentious—it’s comforting to know that the tools of world champions can also live on a kitchen counter. And more importantly: that water is not just something we need to accept or ignore. It’s something we can shape.
Apax Lab a concentrated mineral solution.
Apax Is Coming to Ffocee
We’ll soon be stocking APAX drops on our website — and if you’re curious to explore them for yourself, you can join the list of interest below.
Whether you're chasing clarity, balance, or brightness in your cup, these tiny bottles might just be the most powerful (and overlooked) tool on your bench.
As Simon reminded me: Water doesn’t just carry flavour. It shapes it. And the sooner we treat it as an ingredient — not just a medium — the better our coffee becomes.