What Makes Our Water Solution Better for Coffee?
What Makes Our Water Solution Better?
Your water filtration is probably not doing what you think it is.
That's not meant to be provocative. It's just that most operators chose a water filter based on what the equipment supplier recommended, or what came bundled with the machine, and haven't thought much about it since. The filter gets swapped on some rough schedule, the water looks fine, the machine is running. The assumption is that filtration is handled.
Often it isn't. And the damage accumulates quietly.
What a Resin Cartridge Actually Does
A resin cartridge works through ion exchange. Hard water contains calcium and magnesium ions. The resin swaps those ions out, reducing hardness. For most applications, that's useful. For espresso machines, it addresses one part of the problem.
The part it doesn't address is mineral profile control. A resin cartridge doesn't let you set the calcium and magnesium content to a specific target. It reduces hardness, but how much depends on the cartridge's capacity and where in its lifecycle it sits. A fresh cartridge performs differently than a cartridge at 60% capacity. The chemistry is changing every day between replacements, and you have no visibility into it.
There's no indicator that tells you what your water looks like on day 45 of a 90-day cartridge. You're running on a guess. The machine is running on whatever the water actually is, which may or may not match what you assume.
The second thing resin cartridges don't do: remove chloramine.
The Chloramine Problem
Ottawa water is soft. Softness is often treated as a sign that the water is equipment-friendly. It isn't the whole picture.
Ottawa's municipal water supply is treated with chloramine, which is a disinfectant used in place of, or alongside, chlorine. Chloramine is more stable than chlorine, which is why municipalities prefer it. It also doesn't off-gas the way chlorine does. You can't boil it out. You can't let it sit overnight and have it dissipate.
Standard resin cartridges do not remove chloramine. The ion exchange mechanism targets hardness minerals. Chloramine passes right through.
Inside an espresso machine, chloramine is corrosive. It attacks copper fittings, boiler linings, and internal components at a molecular level. This isn't dramatic or fast. It's slow and invisible. The machine runs, makes espresso, seems fine. Six months in, a year in, the damage shows up as flow restriction, pump strain, temperature instability.
By the time you're experiencing those symptoms, the damage inside the boiler and heat exchanger is already significant. You're not looking at a filter change at that point. You're looking at a descale at minimum, and depending on how long it's been running, potentially a component replacement.
The cost of a boiler descale is real. The cost of component replacement is more so. And neither is covered under warranty, because it's a water quality issue, not a manufacturing defect.
What RO Actually Gives You
Reverse osmosis strips the water essentially to zero. No minerals, no chloramine, nothing. Then you add back the minerals you want, in the concentrations you want, to hit a target profile that's appropriate for coffee extraction.
This is the approach that Water For Coffee by Clearly Simple uses. Their Q400 is designed for single-machine bars. The Q800 handles larger setups. Both are RO-based systems, and both give you consistent output water rather than whatever the tap happens to be producing.
The mineral profile matters for extraction. Magnesium and calcium behave differently in the extraction process. Too little and the coffee tastes flat. Too much and you get scaling and harsh extraction. The right profile for espresso is a specific range, not a direction. Resin cartridges push you in a direction. RO systems let you hit a target.
The consistency piece is what operators don't always think about. When the source water is variable, which it is, because municipal water changes seasonally, by treatment period, and sometimes week to week, the output of a resin cartridge is variable. The output of an RO system with a remineralizer is consistent. That matters for recipe stability, for extraction predictability, and for the long-term health of the machine.
The Economics
The Q400 runs about $250 per year in maintenance. Membranes and filters on the right schedule.
Compare that to a typical resin cartridge setup. Three to four replacements per year at $30 to $50 each is $90 to $200, but that's before accounting for the fact that the resin isn't actually protecting the machine from chloramine, which means you're absorbing damage costs elsewhere. A boiler descale runs $400 to $600. If you need one every two years because your filtration wasn't adequate, that's $200 to $300 per year amortized, and it's unpredictable in timing.
The RO system is more upfront. Installation isn't free. But the ongoing cost is manageable, it's predictable, and it's doing the complete job rather than half of it.
We used to recommend resin cartridges as a primary filtration solution in some situations. We've moved away from that. For shops on Ottawa water, or any water with chloramine in the supply, resin alone isn't adequate protection for commercial espresso equipment. It's not that resin is useless. It's that it's incomplete, and the gap it leaves is exactly the kind of damage that's expensive to fix.
How the Damage Shows Up
Operators usually notice the effects of inadequate filtration in one of three ways.
The most common is flow restriction. Scale accumulates in the boiler and heat exchanger, narrowing the water passages. The pump works harder. Flow rates drop. Extraction times get longer at the same grind setting, which means the barista recalibrates, which means they're compensating for a machine problem without knowing it. Eventually the machine flags an error or stops pulling entirely.
The second is temperature instability. Scale acts as an insulator. When it coats the heating elements or boiler walls, the machine takes longer to reach temperature and holds it less consistently. The shots that come out are at slightly different temperatures depending on how long the machine has been running. The barista notices the coffee tastes different across the day and can't explain why.
The third is pump failure. A pump that's been running under elevated pressure because of flow restriction wears faster. Pumps aren't cheap to replace, and when a pump fails it usually fails during service.
None of these failures are random. They're downstream of a filtration decision. The good news is that they're preventable.
What We Recommend
For almost every shop we work with in Ottawa, we recommend RO as the primary filtration solution. The Q400 for single-machine bars is the standard starting point. Larger bars with multiple machines or higher volume should be looking at the Q800.
The water report from your municipality tells you what's in the supply, including chloramine levels. If you want to know exactly what your water looks like and what your filtration is actually doing, we can test it during a site visit.
If you're currently on resin and you're wondering whether you should switch, the answer depends on your specific water chemistry and your equipment situation. But if you're in Ottawa, the chloramine alone makes a strong case.
The filtration decision is one of the most important decisions you make for your equipment, and it's one that most operators don't revisit after the initial install. It's worth revisiting.
Better Coffee provides equipment sales, installation, and proactive maintenance for specialty coffee in Ottawa and Montreal.
