Making ordinary water taste good for coffee

When we try to make a good cup at home, we run into a huge number of details that can get in the way of making "that same coffee from a coffee shop" in our own kitchen or home coffee bar. I often asked myself what I was doing wrong and why the same coffee I enjoyed in a cafe tasted brighter there, while at home it came out flat, dull and not at all like the cup I wanted.

I spent a lot of money upgrading equipment, buying new brewers and trying different recipes. In the end, I realized that many of those things had much less impact than I expected. From the beginning, I could have made my coffee taste better simply by paying more attention to the water I used for brewing.

Why water matters

Coffee is 99% water, and water plays a very important role in how flavor is extracted from ground coffee. 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 can later adjust: dissolved minerals, or water hardness measured in ppm, and acidity, or pH. For extraction to be efficient and stable, we need water that is soft enough, around 150 ppm, but not completely distilled. With fully distilled water, there is a higher risk of over-extracting the coffee.

Preparing everything you need

To start, you will need these supplies, ingredients and tools:

• three drinking-water-safe containers with a volume of at least 1 liter;
• a small container for mixing;
• a scale accurate to 0.01 g, which is easy to find on marketplaces;
• 3 liters of distilled water;
• baking soda, NaHCO3 or sodium bicarbonate;
• magnesium sulfate, MgSO4 or 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 bottle, 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 or sodium bicarbonate;
• 1 liter distilled water.

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

Preparing hardness

You will need:

• 2.45 g magnesium sulfate, MgSO4 or Epsom salt;
• 1 liter distilled water.

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

Making the final water

Now we have two concentrates: one for buffer and one for hardness. The only thing left is to mix a small amount of each concentrate 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. The 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 what the ingredients do:

Magnesium sulfate: affects extraction quality and helps pull brighter 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.

| Too little baking soda | Balanced | Too much baking soda |

| --------------------------------------------- | ------------------------------------------ | ---------------------------------------------------------------------- | | sharp acidity, lemon-like edge, thin body | acidity becomes softer, balance improves | flat taste, chalkiness, soda-like flavor, muted acidity |

| Too little magnesium | Balanced | Too much magnesium |

| --------------------------------------------------- | ----------------------------------- | -------------------------------------- | | the taste may be empty, watery and under-extracted | more sweetness, aroma and structure | dryness, bitterness, mineral hardness |

Important recommendation: it is better to keep the current ratio of baking soda and 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, and too much of it can negatively affect the taste of your coffee.