Your Water Is Ruining Your Coffee | Northern Front Coffee

A cup of brewed coffee is roughly 98.5% water and 1.5% dissolved coffee solids. That means the quality of your water has an enormous impact on the quality of your cup. You can buy the best beans in the world, grind them perfectly, brew them with flawless technique, and still end up with a mediocre cup if your water is wrong.

What Makes Water Good for Coffee

The Specialty Coffee Association publishes a water quality standard for brewing. The key metrics are:

Total Dissolved Solids (TDS): 75 to 250 parts per million (ppm), with a target of 150 ppm. TDS measures the total mineral content of your water. Too low and the water cannot extract properly. Too high and the minerals interfere with flavour.
Calcium hardness: 17 to 85 ppm. Calcium helps with extraction but causes scale buildup in equipment at high levels.
Alkalinity: near 40 ppm. This acts as a buffer against acidity. Too much alkalinity and your coffee tastes flat and chalky. Too little and the acidity becomes sharp and unpleasant.
pH: 6.5 to 7.5. Neutral to slightly acidic.
Chlorine: zero. Any chlorine or chloramine in your water will produce a medicinal, chemical taste in your coffee.

The Problem with Tap Water

Most municipal tap water is treated with chlorine or chloramine to kill bacteria. This is essential for public health and terrible for coffee. Calgary's tap water, for example, is treated with chloramine and has a TDS around 160 to 220 ppm depending on the season. The mineral content is acceptable, but the chloramine produces a noticeable chemical taste that carries through into brewed coffee.

Hard water areas (much of the Canadian prairies) have high calcium and magnesium content that causes scale buildup in kettles and espresso machines. If you see white deposits inside your kettle, your water is hard.

The Simple Fix

A basic activated carbon filter removes chlorine and chloramine. That is it. A Brita pitcher, a PUR faucet filter, or any countertop carbon filter will handle this for under $30. For most people in most cities, this single change will noticeably improve their coffee.

If you want to go further, you can test your water with an inexpensive TDS meter (about $15 on Amazon) and a general hardness test strip kit. If your TDS is above 250 or below 75, a carbon filter alone will not be enough.

For Advanced Users

If your tap water is very hard or very soft, consider remineralizing distilled or reverse osmosis water. Third Wave Water and Lotus Water sell mineral packets designed specifically for coffee brewing. You add a packet to a gallon of distilled water and get a consistent, optimized mineral profile every time.

This sounds fussy, and it is. But if you have already invested in a good grinder, good beans, and careful technique, water is the last variable to optimize, and it makes a real difference.

The Distilled Water Mistake

Do not brew coffee with pure distilled water. Distilled water has zero minerals, and minerals are essential for extraction. Water molecules need minerals to bond with flavour compounds and pull them from the coffee grounds. Pure distilled water produces a flat, under-extracted cup no matter how long you brew or how fine you grind. It also corrodes metal components in espresso machines over time.

Bottom Line

If you do nothing else, filter your water. A $25 Brita pitcher will improve every cup of coffee you make from this day forward. It is the highest-return, lowest-effort upgrade in all of coffee brewing.