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How I made my own Brewing Water

Updated: Oct 25, 2022

A competitor insight of how to figure out which water matches your competition coffee, based on my experience from the 2022 World Brewers Cup in Australia.

Explanation of terms, used in this article

In this article, I will use a couple of termes that I would like to explain before you start reading.

Total dissolved solids (TDS) is a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionised, or micro-granular (colloidal sol) suspended form. TDS concentrations are often reported in parts per million (ppm). Water TDS concentrations can be determined using a digital meter, a so-called TDS meter.

Reverse Osmosis is a technology that is used to remove a large majority of contaminants from water by pushing the water under pressure through a semipermeable membrane.

Distilled water is water that has been boiled into vapour and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is a type of purified water.


Water is a big mystery to me. I am aware that water is incredibly complexe, actually so complexe, that I have huge respect for it. Water tastes different if you change only 2 ppm of one of its components and makes 98% of our coffee.

It transports flavour or overshadows it, depending on its ingredients.

If we want to use water for brewing coffee, not every water is the same. Some waters have different mineral contents and can push or mute different flavours in our coffee. That is why coffee professionals always recommend filtered water when it comes to brewing coffee or espresso.

The healthiest water isn’t necessarily the best for brewing coffee and tap water? Difficult.

When I profile a competition coffee, there are so many things I have to figure out. Which coffee do I want? Which roast style? Which dripper? Which Paper? Which paper filter? What grinder and is the grind size perfect yet?

It is like juggling with 100 different parameters and never knowing exactly if the decision I made is the perfect one.

And then there is water. In the competition circle it is widely known that certain ingredients in your water can benefit the taste of your brew. That is why most competitors these days make their own water. If it is mixing different types of water, mixing solutions or building it from scratch.

In the following article I want to show you how I approached this topic, how I slowly learned how to make water and what you can do if you want to make your own water. My experiences are based on my practice to compete in the World Brewers Cup 2022 in Melbourne where I placed 11th in the world.

How to start making water

First of all, I am based in Berlin and tap water in Germany is very good with a fantastic drinking quality. However It changes a lot depending on region, household and sometimes even season.

When I first measured the tap water at home I wasn't surprised when I had a total hardness of 21 and a TDS of 420ppm. Berlin water in old flats is quite hard. I knew I had to use filtered water or make it myself.

To measure the total hardness and alkalinity I have used the water test kit from BWT, a company that specializes in water filtration systems, to measure the TDS (Total dissolved solids ) I have used a TDS meter from Third Wave Water, a company that offers products to create your own water. (Imige below)

At the start, I used filtered water from a specialty coffee shop, filtered by using reverse osmosis and mineralised afterwards to match the sca standards of coffee brewing water. The osmosis system was a ROC filtration system from BWT, one of the official sponsors of this years world coffee competitions.

Even if I have had great experiences with this water in the past, it didn’t quite match my coffee this time. Also I would have had to bottle it and transport it to Australia which seemed quite impossible. For me that was more a reinsurance to tackle the scary mystery of making water by myself.

What are the options to make water?

I had 3 options.

Using third wave water, aquacode or buying minerals and mixing my own water cocktail.

Third Wave Water is a company providing mineral mixes in sticks which are designed to ensure the perfect balance of minerals in your brewing water, supposed to optimise the taste of your coffee. You just have to add one Third Wave Water stick to one gallon of distilled or RO ( reverse Osmosis) water, shake, and use it to brew.

Those sticks contain powder, are very easy to use, handy and you can just buy distilled water from the store.

Aquacode is another company that I know of, which provides the same idea. Minerals preportioned that have to be mixed with purified water to make balanced brewing water. The mineral content is a bit different and it provides them in liquid form, which is easier to dissolve.

I really like how easy these mineral concentrates are to use and that you can make them on the spot, achieving consistent results.

The only problem that I actually had was, when I researched distilled water I found out that distilled doesn’t always mean the same. Some waters are distilled using salt or other techniques and they respond differently to the minerals. Another problem was that the mineral content can not be manipulated and I can not enhance single features, according to what matches best with my coffee. So once again, I was unsure.

This is when I reached out to my friends in Australia, competitors and coffee professionals with years of experience. They have told me that using pre mixed minerals doesn't always suit the coffee you are using, the same as online recipes. They are a great guideline or starting point, but as every coffee and every water, even distilled water, is different, it sometimes is better to completely mix the water yourself.

I have opened another rabbit whole….

But I also trusted my friends and I really wanted to evolve and learn more about water, even if that means try and error.

The ingredients

So I had to get 5 basic ingredients:

Purified base water that I could buy in Europe and in Australia with the same quality, Magnesium Chloride, Calcium Chloride, Potassium chloride ( also known as kaliumchloride) and natron.

As a purified base water I got Lauretana recommended. A very very soft Italian water with a total mineral content of 8-9ppm. This water is so soft and pure that it works perfectly as a base water and its quality is always the same as it all gets in bottles in Italy. In Germany most of the organic supermarkets have it in stock.

I ordered all the other ingredients either online or from my local pharmacy ( Apotheke).

Magnesium Chloride

Magnesium chloride Hexahydrat means that one particle of magnesium can take 6 parts of water, the one I bought I got from the pharmacy and it is extra pure to create solutions.

Magnesium can emphasise florality, acidity and sweetness in a coffee.

Calcium Chloride

Calcium chloride is available as powder or liquid. Both versions work well. My friends suggested the liquid one but after a lot of tries I found the powder worked better for me as I found it easier to dose.

The powder I used was 100% pure water free calcium chloride that I ordered online.

Calcium binds sweetness and pushes the body of a coffee. It creates a structure for the flavour and helps transitioning flavours to shine.

Potassium and Natron

Both of those I got online and they act as a so-called “buffer” in your water. They bind all the minerals together, regulate the PH.

Now that I had all the ingredients, I had to start mixing solutions.

Many people have suggested different options, how I should do water so I just want to emphasise that this is the way I did it. It doesn't mean it's the only or the correct way, but by sharing my experience I hope I can take some of the fear away when it comes to making water. I had so many people talk at me that I literally didn't even want to make water and I forced myself to go through this rabbit hole and learn as much as possible. Please remember: water and coffee are organic and in the world of flavour there is never a ‘correct way’ to do anything and no set recipe for success.

Mixing solutions

I used 1l Lauretana water and added 6g magnesium chloride, closed the bottle, labelled the bottle, shook it and placed it in the fridge.

For the calcium chloride solution I used 4g on 1l of Lauretana and did the same.

For my buffer I mixed 1g natron and 1.2g Potassium together and added it to 1l of Lauretana water.

After all bottles were clearly labelled and closed in the fridge, I let them sit for a night.

Those bottles were my base solutions and I could use them to try different ratios. According to the sca the perfect brewing water has a tds between 75 and 250ppm so within this, I can try different ratios.

I measured the TDS of the Lauretana each time, because it varied from 8-11ppm with the TDS reader from third wave water.

And to be honest, I just tried everything. The only thing I knew is that the buffer is usually very little and more magnesium gives more florality. Too much magnesium makes the coffee soapy and astringent. The measurements are very small and you have to be very detailed, that is why I used syringes to slowly add the minerals one by one. Depending on how much water I was making ( 1 liter to try or 5 liters to make multiple brews) I added millilitre by millilitre, then closed the bottles and swirled them to mix everything, then measured the TDS and so on and so on.

I settled for a total ppm of 105 containing 10ppm Lauretaner water, 15ppm buffer, 40ppm magnesium chloride and 40ppm calcium chloride.

However, some days my coffee tasted better with 50ppm magnesium chloride or other measurements of the given ingredients. I had to try it out every single day. The more I tried it, the more I got a feeling for it. I got an idea of how the coffee interacts with the minerals and also different brewing temperatures.

When we got to Australia, one of our friends had already organised Lauretana water and we could start comparing waters. Interestingly Sam Corra, head of coffee at ONA, world vize brewers cup champion 20187 and mastermind behind many world competitors like World Brewers Cup Champion Matt Winton and a dozen more, suggested Sydney tap water as it is apparently magical. So we also organised 10l of this to get driven to Melbourne.

After brewing my coffee with a lot of different waters, I had to make a decision. Together with some of the world's best brewers we decided for the self made water with 40-40-15 ratio I have explained earlier.

It gave the coffee florality and lightness.

But to be honest, I know that if I would have ground my coffee slightly differently I would have probably needed a different water recipe again.


So no matter what you do: just enjoy the learning path and the flavour experience you get. After making about 300l of water at home, carrying 200 glas (!!!) bottles from the supermarket to our flat and back, I am fairly certain that there is no correct recipe, not one special wonder water and no ultimate formula to success.

I think overall I have seen many competitors using Lauretana water and some also mixed it with a mineral water of their choice, or went straight with a bought mineral water.

If you do so, take a look at the hydrogencarbonat amount and that it is quite low, meaning under 100. Hydrogencarbonate is a naturale neutraliser of acidity, great for overly acidic bodies but not great for our coffee taste. Some really healthy waters that are on the market are so healthy because they are full with minerals, making it hard for delicate coffee flavours to shine through.

If you are overwhelmed with the topic, I can recommend the soluble minerals that are pre mixed and are added to distilled water. You have great water with constant quality and can focus on all the other parameters that are so difficult to master.

For me, learning about different waters was scary at first but super interesting the more I tried. I love the diversity of options and the impact water has on our flavour conception.

I hope this insight is helpful and I encourage you to make your own experiences. If you need any help do not hesitate to reach out.

Until then, have fun exploring the rabbit hole water for yourself.

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