Although it makes up 98-99% of the final cup, water often doesn’t get the love and attention it deserves. Even if you’re starting with the highest-quality beans, everything can be spoiled if your brewing water just isn’t up to par.

Then, there's brewing temperature: the ideal heat level to unlock all those sweet and aromatic flavours from ground coffee without drawing out too much bitterness. It’s a delicate line to walk, and it's always changing depending on your brewing style and roast level.

Here at Eight Ounce, we coffee obsessives walk that line many times each day as we brew countless different coffees, testing every variable. We're here to guide you through the best practices for optimizing and heating your water, including time-tested guidelines outlined by the Specialty Coffee Association (SCA), to ensure that your coffee can truly live up to its fullest potential!

The best water for brewing coffee, according to the pros

Does the coffee at home fall short of the quality at your favourite café? If you’ve already invested in a highly qualified grinder and brewer, water may just be the hidden culprit.

The Specialty Coffee Association has spent a lot of time researching the pinnacle chemical composition of brewing water, measuring key factors such as Total Dissolved Solids (TDS), Calcium, Alkalinity, pH level, odour, and colour.

After looking closely at each of these parameters – and how they affect flavours in the cup – they developed a standard recipe for water that helps consistently produce excellent coffee.

Even to a discerning coffee enthusiast, these data-driven numbers* and technical jargon can seem daunting: how much do they really matter? How does one variation over another affect flavour? Don't worry – we've got the A's to your Q's:

*Note: the numbers below defined in ppm (parts per million) refer to the SCA acceptable ranges for each parameter! 

Total dissolved solids: SCA Range – 75-250 ppm

Think of minerals as extraction accelerators, responsible for pulling flavour compounds from ground coffee into the water. If the mineral levels are too low, the resulting cup will taste watered-down and hollow. Too high, and flavours become over-extracted and unpleasantly potent.

Total Dissolved Solids (TDS) refers to all dissolved minerals in water, including salts and organic compounds. The SCA recommends a target TDS level of 150 ppm, which falls right in the sweet spot!

Water hardness: 50-175 ppm

Not to be confused with TDS, which measures every single dissolved substance, water hardness refers specifically to the concentration of calcium and magnesium – both very adept at extracting flavour compounds from ground coffee in different ways:

Calcium adds body, creaminess, and contributes to a smoother consistency. Magnesium, on the other hand, boosts sweetness and clarity. When balanced properly, they create a deeply complex and flavourful cup.

As with most things, moderation makes all the difference. While hard water is preferred because it contains the calcium and magnesium beneficial to extraction, too much mineral concentration can lead to harshness and bitterness – not to mention the limescale buildup on your brewing equipment!

According to Third Wave Water, keeping water hardness below 175 ppm “prevents rapid limescale formation that clogs water lines, coats heating elements, and damages pumps and valves” (Third Wave Water, 2025).

Alkalinity: 40-70 ppm

Alkalinity refers to water’s buffering capacity, or its ability to neutralize acids.

In coffee, a touch of acidity gives coffee its bright, complex character while balancing out the bitter compounds extracted late-brew. However, if your water is overly alkaline (a.k.a contains too many buffers and thus neutralizes all that good acidity) you’re left with a flat, dull, and hollow cup.

The SCA’s recommended Alkalinity content of 40 ppm (parts per million) lets just enough acidity shine through, but keeps just enough buffers around to tamp down the excess.

pH Level: 6.5-7.5 (target 7.0)

pH is a scale used to measure how acidic or basic a solution is. The SCA recommends a pH level of 7.0, which is perfectly neutral on the charts, to prevent throwing off flavour balance by adding unwanted acidity or bitterness!

Odour & colour: clean/fresh, odour-free

Simply put, brewing water should be completely free from any odours... but sometimes the odds are stacked against us. For instance, many municipal water supplies contain chlorine, a chemical disinfectant (with a very distinctive smell) – and while this is safe for consumption, even trace amounts can completely suppress the delicate aromatic compounds and nuanced flavours in coffee.

Further, your brewing water should be completely clear, free from suspended particles and off-colours. If you can see any impurities floating around, they’ll almost certainly end up in the final cup!

How the Coffee Club Café optimizes Calgary's drinking water

By general standards, Calgary's water quality is considered "hard", or highly concentrated with minerals like calcium and magnesium. That's because our reservoirs are supplied by the Bow and Elbow Rivers, which both collect limestone and other mineral-rich deposits as they flow through the nearby Rocky Mountains.

To get really specific, here are the exact water hardness ranges from 2025, divided into two zones. For reference, the SCA recommends a water hardness between 50-175 ppm when brewing coffee:

Bearspaw range

• January to March: 151-200 ppm
• April to June: 141-192 ppm
• July to September: 151-177 ppm
• October to December: 168-197 ppm

Glenmore range

• January to March: 208-274 ppm
• April to June: 181-245 ppm
• July to September: 191-216 ppm
• October to December: 213-248 ppm

How does the Eight Ounce Coffee Club Café account for these especially high mineral levels? We treat our brewing water with a two-phase approach: First, we run it through a reverse-osmosis filter (which resets minerality to zero), then we replenish it with a custom dilution of magnesium and calcium. Our chosen ratio fluctuates throughout the season, but the goal is always to keep our coffee tasting vibrant, complex, and consistently delicious.

Because we're always keen to show how wonderfully diverse specialty coffee can be, our café offers a seasoning station featuring the full lineup of APAX Water Minerals (more on water seasoning below!). After picking up your coffee, you can further customize its flavour by adding a few drops of whichever one calls to you! Looking for a more robust body, or to amp up acidity? We've got a mineral concentrate for that.

Where to get SCA-approved brewing water

Not everyone has access to the same commercial water treatment systems as their local specialty coffee shop. Fortunately, there are still plenty of accessible (and affordable) ways to optimize your brewing water at home! 

Filtered water

Activated-carbon filters are commonly used to eliminate chlorine and organic compounds from waters. They can also be found in most water filtration systems that you may already have in your fridge, making them easy to incorporate in home-brewing routines!

However, this method is less ideal for decreasing water hardness levels, as most soluble minerals can easily slip through the filter! 

Reverse-osmosis

Reverse-osmosis systems strip away 99.9% of total dissolved solids from your brewing water. It also removes some of the minerals you actually want, like magnesium and calcium, which are both conducive to extraction.

While reverse-osmosis water isn't recommended for brewing as-is, many discerning aficionados see it as a blank canvas. It lets them mix in their own minerals, customizing their coffee's flavour by enhancing certain attributes like vibrancy, sweetness, or texture.

The best water temperature for coffee

Once you’ve sourced the best water for brewing, the next essential step is making sure it’s heated to the appropriate temperature.

If the water’s too hot, you’ll overshoot extraction, winding up with primarily bitterness in the cup. Too cool, and all those wonderful flavours remain locked inside the grounds – especially sweetness, which is tougher to break down. As a result, coffee tastes weak and sour.

The goal is to extract just enough to create a balanced, well-rounded cup with ample sweetness and complexity.

According to the SCA, the sweet spot falls in between 93–96°C (200–205°F). Within that range, the best temperature depends on the roast level of your beans:

• Light roasts: 94°C-96°C (202°F-205°F): Because they’re much denser (even when ground) lightly roasted beans benefit from slightly higher brewing temperatures to unlock their full sweetness and flavour complexity.
• Medium roasts: 92°C-95°C (198°F-203°F): As you may expect, medium roasts fall squarely in the middle of the spectrum, calling for water that’s just hot enough to unlock delicate flavour compounds without quickly over-extracting.
• Dark roasts: 90°C-93°C (195°F-200°F): Relative to light and medium levels, dark-roasted coffee beans are the most porous and broken down, so it doesn’t take much to draw out their flavour. Brewing with cooler temperatures helps to prevent accidental over-extraction!

Tips to master your brewing temperature

If you’re interested in hitting accuracy to the exact degree, we recommend a kettle with temperature control, like the Fellow Stagg EKG.

Sometimes, the difference between an underwhelming coffee and an exceptional one is a degree or two. Temperature-controlled kettles let you hit that precision with ease, and save you from revisiting your grind setting or dose.

If you’d like to achieve similar control with a stovetop kettle, we recommend starting from 100°C, the boiling point*, and removing for a few seconds depending on the temperature you’re aiming for.

• For light roasts: 30-45 seconds off the boil
• For medium roasts: 45 seconds-1 minute off the boil
• For dark roasts: 1-1:30 minutes off the boil

Fun fact: the boiling point for water decreases at higher altitudes! If you’re 5,000 above sea level, your boiling point is 95°C.

Is your coffee missing the mark? Here are the common issues, and why they might be happening:

How to "season" your water like the pros

We love elevating our coffee's flavour in any way we can, which is why the Eight Ounce Team is always reaching for these brewing water enhancements... you can even find them at the hand-off bar in our café!

• APAX Lab Water Minerals: Customize your coffee's brightness, sweetness, and body with APAX Lab's four distinct mineral concentrates. Add a few drops into your water before brewing, or directly into the coffee!
• Third Wave Water: Tailor your water's mineral composition to fit different roast profiles, with Classic Light, Medium, and Dark sachets! Simply add one pack to distilled or reverse-osmosis water before brewing.

Give your water the care it deserves – it's worth it!

Beyond all the technical specs and data, great coffee simply deserves great water. And even if you don't have the benefit of a commercial filtration system hooked up in your kitchen, sourcing the best-possible brewing water doesn't have to be a heavy lift. 

Afterall, you and everyone involved in the chain – including producers, quality graders, and roasters – have already poured lots of care into your coffee; pairing it with the right water is the best way to ensure all that passion reaches the final cup!

Our Sources

1. What is SCA Water Standard? Complete Guide to Coffee Brewing Water Quality. (November 2025). Third Wave Water. Retrieved October 16, 2026 from https://thirdwavewater.eu/blogs/news/what-is-sca-water-standard-complete-guide-to-coffee-brewing-water-quality.
2. Ideal Water Temperature for Coffee (n.d.). Roast Coffee Co. Retrieved October 16, 2026 from https://www.roastcc.com/learn/coffee-water-temperature.
3. Water quality, hardness and data(n.d). City of Calgary. Retrieved October 20, 2026 from https://www.calgary.ca/water/drinking-water/water-quality-water-hardness-water-data.html