How Water Quality Affects Your Coffee – The Best Water to Use for Coffee

Why Does Water Quality Matter for Coffee? In short, your cup of coffee is mostly water. So it makes sense that the water you use can have an effect on how your coffee tastes.

So, what does the water actually affect?

We won’t get into the scientific side of things but, when you brew coffee, the water pulls all those lovely flavours and aromas out of the coffee grounds.

The water doesn’t just take all the flavour out at once. Different things in the water can affect what gets extracted, how much gets extracted and how those flavours come through in your cup. This is why changing your water can change the way the same coffee tastes.

For example, the same coffee might taste sweet and balanced with one type of water, but flat, bitter or even sour with another.

The water itself can also bring its own flavours to your coffee. If your tap water has a strong chlorine taste, an unusual smell or a lot of mineral content, you may notice it in your coffee too.

Pretty important for something we usually drink all the time, right?

Now comes the most asked question. What Is the Best Water to Use for Coffee?

In a nutshell: Fresh, Clean, Filtered Drinking Water.

As we’re in Thailand, one should never use tap water to make coffee. Unless you have a proper filtration system in place that makes it suitable for drinking. 

For everyday brewing, our recommendation is any one of these options:

💧 Water from a good home filtration system

Usually a clean, consistent option. Depending on your filtration system, it can reduce unwanted tastes and smells while leaving some minerals in the water. Your coffee may taste clean, balanced and clear.

💧 Filtered drinking water

A simple everyday option that can give you a cleaner, smoother-tasting cup, especially if you’re used to water with a noticeable taste or smell. Different filters remove different things, so the result can change from one filter to another.

💧 Bottled drinking water or Imported mineral water

This is where things can get interesting! Different bottled waters have different mineral contents, so you may notice changes in sweetness, body, brightness and overall balance. Some may make your coffee taste softer and smoother, while others can make certain flavours stand out more.

💧 Imported mineral water

This can be a fun one to experiment with. Different mineral waters have very different mineral profiles, which can change how much sweetness, acidity and body you notice in your coffee. Some may make a coffee taste brighter and more lively, while others may give it a rounder, fuller feel.

💧 Water from the air

Water made by capturing moisture from the air can be very low in minerals, depending on the system and how the water is treated afterwards. Because mineral content can affect coffee extraction. A very low-mineral water may produce a cup that tastes lighter, softer or less expressive than a water with some mineral content.

Our tip: try a little coffee water experiment!

Brew the same coffee using two or three different waters and taste them side by side. Keep everything else the same. Same coffee, same grind and same recipe. You may be surprised by how much the water changes the final cup. That’s half the fun of coffee!

Here are a few clues:

• Your coffee suddenly starts to taste different even though you’re using the same beans.
• Your coffee tastes dull or flat.
• White mineral deposits build up quickly in your kettle or coffee maker.
• Your machine needs descaling more often than you’d expect.

1. Use fresh, clean water – Start fresh every time you brew.
2. Don’t rely on distilled water alone – Coffee generally benefits from some mineral content.
3. Keep your machine clean – Regular cleaning and descaling help keep both the machine and your coffee tasting better.
4. Experiment – Your local water is unique, so try different options and see what tastes best with your coffee.

You don’t need expensive or specialised water to make a great cup of coffee. For most of us, the best water to use for coffee is simply fresh, clean drinking water that tastes good. So the next time your coffee isn’t tasting quite right, don’t immediately blame the beans. Make sure to first check the water you’re using.