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July 29, 2019 /
DIY Water Recipes Redux

A couple of years ago, we published a method for making your own water recipes, using concentrated mineral solutions, diluted with deionised water, to make a range of waters with different hardness and alkalinity. This post updates this, with new recipes that allow you to easily target a specific GH and KH in your water.

We’ve also added in a calculator that allows you to work out what will happen if you add minerals to existing water, rather than just deionised water. This will be useful to anyone in soft water areas who would like to remineralise their tap water, for example.

This post has been update to correct a slight error in one of the calculations: thanks to Johannes Wintz for putting us straight!


The Concentrate Recipes

You’ll need the following before you start:

  • Baking Soda – NaHCO3, Sodium Bicarbonate (not to be confused with baking powder)
  • Epsom Salts – MgSO4.7H2O, Magnesium Sulphate.¹
  • Deionised/Distilled/Ultra-pure water
  • Scales (accurate to 0.01g)
  • 3 x ~1L water containers (preferably glass, and odour/residue free)

The Buffer Solution

Dissolve 1.68g of sodium bicarbonate in 1L of deionised water. This creates a solution with a KH (as CaCO3) as close as we can get to 1000ppm.

The Hardness Solution

Dissolve 2.45g of Epsom salts in 1L of deionised water. This creates a solution with a GH (as CaCO3) of 1000 ppm.


Create Your own Water Recipe using Deionised water

Using these two solutions with deionised water is very simple. To get your desired KH and GH, you can simply use that number of mls of each solution, then make the total volume up to 1L with deionised water.


Mineralise Pre-existing Water

If you prefer to add hardness or buffer to existing water, perhaps to take advantage of the calcium or other minerals already in the water, then you can use this calculator to work out what the final KH, GH, and TDS of your water will be. This is helpful if just want to boost the hardness of your favourite bottled water, for example, or to mineralise your tap water if you live in a soft water area.

To use this calculator, measure the KH and GH of your existing water (and optionally your TDS), then put these numbers into the calculator along with the amounts of each solution you plan to use.

You’ll see that adding 10ml of a solution doesn’t simply increase KH or GH by 10, like it does with distilled water. This is because the solutions themselves dilute the water that you started with. By tweaking the amounts of each solution that you use accordingly you should be able to work out what amount will get you your target GH and KH.


Why are these Recipes Different?

Our previous solutions were designed to give you 1g/L of magnesium or bicarbonate ions, respectively. However, this is not the way that we usually measure hardness and alkalinity.

Rather than give the concentration of the ions directly, both hardness (GH) and alkalinity (KH) are usually measured in calcium carbonate equivalents. In other words, it tells you how many parts per million of calcium carbonate you would have, if all the hardness or alkalinity was due to calcium carbonate alone.

It’s measured this way because simple drop test kits can’t distinguish between calcium or magnesium ions, so it’s easiest to assume it’s all calcium. This means that when we start using magnesium or sodium salts to tweak the water, we need to do a bit of maths to convert those amounts into CaCO3 equivalents.

To make it easier for you to experiment with different hardnesses, we’ve altered the recipes to aim for a specific KH and GH instead. This means that you can easily target any GH or KH you like, with no conversion required.


The Water Recipes

These are the original Barista Hustle water recipes, updated for use with the new concentrates.

Recipe 1 – Melbourne

  • 11.5g Buffer
  • 23.7g Mg
  • 964.8g DI water

This is a close approximation to Melbourne water. This is very “soft” water, low in mineral content, and useful for those long filter brews or cuppings drawn out over five to ten minutes. Would also help with those darker espresso roasts that don’t need as much help extracting out flavours. 

Recipe 2 – WOC Budapest

  • 40.1g Buffer
  • 51.2g Mg
  • 908.7g DI water

This is in the target range for the World Brewers Cup in Budapest (51 mg/L total hardness as CaCO3, 40 mg/L alkalinity). In Budapest the total hardness would come from calcium as well as magnesium, leading to a different flavour outcome — competitors beware …

Recipe 3 – SCA

  • 40.1g Buffer
  • 68.6g Mg
  • 891.3g DI water

This is the official SCA specifications from the SCAA 2009 handbook. Similar to Budapest only the total hardness has gone up slightly. The specifications state a range of total hardness as low as 17 mg/L as CaCO3 up to 85 mg/L as CaCO3. So you could keep your buffer here constant at 40.1g and go as low as 17g of Mg solution or as high as 85g (don’t forget to subtract the total concentrates used from your DI water!).

Recipe 4 – Barista Hustle Water Recipe

  • 40.1g Buffer
  • 80.7g Mg
  • 879.2g DI water

The original Barista Hustle water recipe — where it all began. Add an extra 4.3g of the Mg concentrate and you’re at the top limit of the SCA specifications.

Recipe 5 – Rao Water

  • 50.1g Buffer
  • 75.7g Mg
  • 874.2g DI water

This is close to Scott Rao’s recommended water chemistry for brewing flavourful, balanced coffee. Slightly higher than the SCA in both total hardness and buffer, with a little more buffer than the BH recipe.

Recipe 6 – Hendon Water

  • 30.8g Buffer
  • 99.9g Mg
  • 869.3g

This is close to the centre of Christopher Hendon’s and Maxwell Colonna-Dashwood’s “Ideal Brew Zone”. If you’re inclined to “dial in” some water for a particular roast, this is a good starting point.

Recipe 7 – Pretty Hard

  • 35.1g Buffer
  • 126.1g Mg
  • 838.9g DI water

This begins the ascent up in water “hardness”, probably better suited to espresso, or at least short brew times for filter. This is starting to grab a lot out from the coffee so brew recipes would need some adaptation. This rips everything out from the coffee. So either slow down or speed up the brew time via grind adjustments, and shorten or increase your beverage weight. Dependent on the roast somewhere along those two spectrums you’ll find something tasty. Or not.

Recipe 8 – Hard dot AF

  • 45.2g Buffer
  • 176.8g Mg
  • 778g DI water

This is a fairly high point with pushing mineral level where you’re basically cranking the amp up to 11. Your brew parameters from the earlier water recipes would need to change a lot here.


A Note about TDS

Note that the TDS given by this calculator might not be exactly the same as the TDS you would see if you measure the resulting solution with a TDS meter. This is because TDS meters assume a certain ratio of all the ions in the water, and by adding these solutions, we’re messing with that ratio.

¹ The “.7H2O” part refers to the fact that water forms an intrinsic part of the crystal form of this salt that you can buy in the shops, which is the clear crystals called Epsom Salts. Each magnesium sulphate molecule is surrounded by seven water molecules in this type of crystal. We’re specifying this here, as the weight of the water in the crystal affects the calculations.

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Joe Lawless
Joe Lawless

Nice! I love the idea of using low hardness tap water as a starting point, maybe with a carbon block to clean it up.
I’ve flipped the water calculator around so that you enter the target water and it tells you how much of each solution to add.


Hey, i have a knot in head.
What should be the final ppm of the crafted water?


Quick question. Baking soda is made up of sodium and bicarbonate at 27% sodium the rest bicarbonate. So if we have 50g of the buffer in 1 L of water isn’t it only 36.5ppm of bicarb and 13.5ppm of sodium. Is this correct thinking? This also applies to the epsum salt also.

Chris S.
Chris S.

I’ve begun crafting water for espresso using the above as a guide and, so far, I’m pleased with the results. It truly is amazing how great an impact the water chemistry has on the extraction!

Kathryn Havelka
Kathryn Havelka



Hi BH. Thank you for updating the DIY water recipes.

If was to use Potassium Bicarbonate as the “buffer” would the 1.66g per litre of Distilled water still be the correct calculation for the concentrate?



Thanks so much for this. One questions – ive been using the ‘barista hustle original’ water for filter v60 brews, and in general, ive been really happy with body/mouthfeel, acidity and balance in terms of taste, however I am struggling with getting much aroma (which i’ve gotten in the past from cafes with, say, natural process ethiopean beans). The aroma when i make coffee at home always seems subdued. For background regarding how i brew at home – I use lighter roast coffee from different well regarded specialty sydney & melbourne roasters, and gravitate towards natural ethiopian, brew about 23g… Read more »

Brandon G
Brandon G

What’s the best way to add the concentrates to the third glass container? Dealing with tenths of a gram seems to be difficult by just pouring from a separate 1L bottle. Thanks!


If you happen to have a calibrated pipette lying around I’d follow BH’s advice… but as for myself I’ll be using a little squeeze bottle ¯\_(ツ)_/¯

Mohammed Al-Hellabi
Mohammed Al-Hellabi

I’m using magnesium chloride, calcium chloride, and potassium bicarbonates and would like to know how can I have the same results using these minerals (specifically the mg and ca). For instance to have a total GH of 80 ppm, should I divide it to 40 mgcl and 40 cacl? How can I play with both of them to reach to the same results above?

Gordon Haywood
Gordon Haywood

Note there is no reference to the pH of the deionised water. I’m using water with a pH of 6, TDS of 10, almost zero of anything else. What assumption if any is made re pH of the deionised water, and what would you expect the pH of the resultant mix (in calc 1) might be? Thanks.

Scott Manley
Scott Manley

Hi Gordon – Deionized water by definition has a pH of near 7 at 25C (77F) initially. When it comes into contact with the atmosphere it will absorb C02 and form carbonic acid, which will lower the pH. It sounds like you are using either distilled water; or RO water that naturally has low pH. Note that measuring pH can be tricky and is highly temporal. Also, the neutrality point of 7 is only true at 25C/77F. Meaning that as water temperature changes, so does the neutrality point. For example, the neutrality point of water at 200F is 6.14 pH.… Read more »


Just wondering because baking soda is supposed to breakdown beyond 50 ‘C in solid form, is this the same in aqueous form?


So I’ve been using these BH recipes since the original article and definitely have seen an improvement in my coffee versus my RO water brews. Just curious though, a few days after I’ve made my concentrates, some sort of salts start to precipitate out of my water and settle at the bottom of the container. Stirring/shaking doesn’t redissolve them either. I’ve tried making the solution at different total volumes, storing at room temp and refrigerated, and I get the same results every time. I’m no chemist, but some sort of reaction is occurring. Any thoughts or suggestions??


Hi! I would like to ask how long I could keep the solutions/concentrates for? Do they need a cool environment? Thank you


Hello, I was wondering instead of making the concentrates can I just weigh out the magnesium and sodium bicarbonate in milligrams then add that to distilled water? If so how many mg per liter would I need to add to get the same results at the barista hustle recipe? Thanks


Hello, I was wondering how you would calculate the mixtures with these kind of solutions that equate to roughly 1000ppm but still use the recipes listed in the 2017 article on DIY Water Recipes. The 2017 solutions do not equate to 1000ppm so it is not a direct translation to the new way of mixing them in this 2019 article.


In the water problem, I prefer to use Mineralise Pre-existing Water, which makes the water formula simpler by simple mathematical calculations, especially for the contestants. (But the cost will be higher than the first method. Deionized water usually has a retail price of about 2AUD/5L in mainland China)      In my hometown, the “NingXia” in the northwestern province of China is usually 200-600 PPM, and the water’s alkalinity and pH are also very high. (Compared to Melbourne 20-40PPM, this is the difference between heaven and hell.) Usually the water hardness in these areas is extremely high, and the kettle will… Read more »


I still have a few questions. If you add the calcium and magnesium ion concentrate directly in deionized water (pH=7) without adding sodium bicarbonate, will this make the taste of the coffee worse? The second question is about KH = 40 mg/L. This is the standard required by SAC, but why is it 40? What is the basis here?
Thanks to the magical BH team, I and many Chinese baristas want to know what this is.

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