Making Good Water for Coffee

Making ordinary water taste good for coffee

When we try to make a delicious cup at home, we run into a huge number of obstacles and details that can get in the way of making "that same coffee, like in a coffee shop" in our own kitchen or home coffee bar. I often asked myself what I was doing wrong and why the exact same coffee I drank in a cafe tasted better and brighter there, while when I tried to repeat it at home, I ended up with a flat, dull cup that was nothing like it.

I spent a lot of money upgrading my equipment, buying new brewers, and trying a lot of recipes. In the end, I came to the conclusion that many of those things barely affect the result, and from the very beginning I could have made my coffee taste better simply by paying more attention to the water I was brewing with.

Why water matters

Coffee is 99% water, and water plays an extremely important role in how flavor is extracted from our ground coffee. In general, one of the most important things to pay attention to after choosing the coffee itself is the water you brew it with. Bad water can ruin even very good and expensive coffee. Good water, on the other hand, can help bring out flavors and aromas even from fairly average coffee that would be hard to extract with mediocre water.

How it works

There are two water parameters we care about and will later adjust: dissolved substances, or water hardness (ppm), and the acidity of the environment (pH). For extraction to be as efficient and stable as possible, we need water that is soft enough, around 150 ppm, but not completely distilled. Otherwise, there is a high risk of over-extracting the coffee.

Preparing everything you need

To start, you will need the following supplies, ingredients, and tools:

• Three drinking-water-safe containers with a volume of at least 1 l
• A small container for mixing
• Scales accurate to 0.01 g (they are easy to find on marketplaces)
• 3 liters of distilled water
• Baking soda (NaHCO3 Sodium bicarbonate)
• Magnesium sulfate (MgSO4 Epsom salt)

Important: make sure the mixing containers are clean and certified for drinking water.

Making the water

We need to prepare three bottles. In the first one, we will make a baking soda buffer. In the second, we will make a magnesium hardness concentrate. The third bottle will be used for the final water.

Preparing the buffer

You will need:

• 1.68 g baking soda (NaHCO3 Sodium bicarbonate)
• 1 l distilled water

Mix this in one bottle and label it "KH/buffer".

Preparing hardness

You will need:

• 2.45 g magnesium sulfate (MgSO4 Epsom salt)
• 1 l distilled water

Mix this in one bottle and label it "GH/hardness".

Making the final water

We now have two concentrates: one for buffer and one for hardness. The only thing left is to mix a small amount of these concentrates with distilled water to get the right hardness. I made my first water recipe based on a recommendation from Barista Hustle, and I can say that it is a good universal recipe:

• 40.1 g KH/buffer
• 80.7 g GH/hardness
• 879.2 g distilled water

That is it — our water is ready.

How to control the recipe

One of the most important advantages of this recipe is that you can adjust it to your taste. To do that, it helps to understand how the ingredients work:

Magnesium sulfate: affects extraction quality and helps pull bright acidic notes, sweetness, and sparkle from ground coffee.

Baking soda: affects body and balance in the cup. The more baking soda you add, the denser and easier-drinking the cup becomes, but it also reduces acidity.

Important recommendation: it is better to keep the current ratio of baking soda + magnesium to water and avoid increasing the overall hardness too much (the total amount of baking soda and magnesium creates the overall hardness of the water), because this can negatively affect the taste of your coffee.