Here I propose a water product that BH Tools could offer. Actual release is pending the community's response and how annoying the things-I-haven't-thought-about-yet are. Criticism and feedback is very warmly welcomed on [instagram](https://www.instagram.com/matt.perger/) or [xwitter](https://x.com/mattperger). ![[Dropper Bottles.jpg]] The [DIY water recipes page (2.0)](https://www.baristahustle.com/diy-water-recipes-redux/) at Barista Hustle has been one of the most reliable organic traffic sources ever since it was published. [Apax Lab](https://apaxlab.com/) has swept coffee competitions overnight. [Lotus Water](https://lotuscoffeeproducts.com/) is popular and reliable. It's clear the people want better water. But water is hard (heh), and we're all still kind of learning about it. There's almost undoubtedly delicious but yet to be tried ion blends out there! Both Apax and Lotus are big inspirations for this idea. Simon Gautherin knocked it out of the park with Apax and has completely changed how I think about water for coffee. ## The Pitch **Aim:** make custom ion formulations affordable, easy to craft, and simple to share/emulate/discover. **Product:** - approx. 10 sachets of dry chemicals to make concentrates - 10 dropper bottles (polypropylene bottle and maybe glass droppers?) - users BYO pure water (>80% of the shipping weight and available everywhere) - simple instructions for creating concentrates with 0.1g scales - a simple web app to help users create, discover, and save recipes - instructions for creating a grid of cups for exploring the map of possible water chemistries (eg a 5 x 5 grid with Mg/K on the x axis and Cl/HCO3 on the y axis) - all specs published so anyone can make and/or sell their own concentrates and blends I'm thinking a good combination of chemicals would be: 1. **Magnesium Chloride Hexahydrate** _(MgCl₂·6H₂O)_ 2. **Magnesium Sulfate Heptahydrate** _(MgSO₄·7H₂O)_ 3. **Sodium Chloride** _(NaCl)_ 4. **Sodium Bicarbonate** _(NaHCO₃)_ 5. **Sodium Citrate** _(Na₃C₆H₅O₇)_ 6. **Potassium Chloride** _(KCl)_ 7. **Potassium Bicarbonate** _(KHCO₃)_ 8. **Potassium Citrate** _(K₃C₆H₅O₇)_ 9. **Calcium Chloride Dihydrate** _(CaCl₂·2H₂O)_ 10. **Sodium Metasilicate Pentahydrate** _(Na₂SiO₃·5H₂O)_ _(Silica)_ It would be great if each of these concentrates were standardised so that 1 drop (~0.068g) = 10ppm in 100ml water, or something similarly pleasing. The web app would probably be configured around multiples of "1 drop" of each concentrate rather than trying to slice them into fractions. This is beyond my pay grade, but in the case of **Magnesium Chloride Hexahydrate** _(MgCl₂·6H₂O)_ I get the following: - **Molar Masses:** - **MgCl₂·6H₂O:** 203.3 g/mol - Mg: 24.3 g/mol - Cl₂: 70.9 g/mol - 6H₂O: 108.1 g/mol - **Ion Mass Fractions:** - **Mg²⁺ Fraction:** 24.3 g/mol ÷ 203.3 g/mol = **0.1196** - **Cl⁻ Fraction:** 70.9 g/mol ÷ 203.3 g/mol = **0.3490** - **Total Ion Fraction:** 0.1196 + 0.3490 = **0.4686** - **Mass of MgCl₂·6H₂O per 0.068g Drop:** - **Desired Total Ions per Drop:** 1 mg - **MgCl₂·6H₂O per Drop:** 1 mg ÷ 0.4686 = **2.134 mg** - **Concentration in 100 ml Solution:** - **Concentration (% w/w):** (2.134 mg ÷ 68 mg) × 100% = **3.14%** - **Mass to Dissolve:** 100 g × 3.14% = **3.14 g** - **Ions per Drop:** - **Mg²⁺ per Drop:** 2.134 mg × 0.1196 = **0.255 mg** - **Cl⁻ per Drop:** 2.134 mg × 0.3490 = **0.745 mg** - **Total Ions per Drop:** 0.255 mg + 0.745 mg = **1 mg** In English: Creates a ~3:1 ratio of chloride to magnesium. Requires 3.14g of the chemical to make 100ml concentrate. 100ml = 1470 drops. ## Rationale Assembling all of these chemicals would be **expensive** and annoying in the usual quantities that they're available. My thinking for multiples of some ions is that sometimes you want to add a cation but you don't want to raise its anion, so if you wanted more magnesium and preferred sulfate you would choose magnesium sulfate instead of magnesium chloride. The lotus water kit for example only has 4 droppers so if you want sodium you're only ever getting chloride along with it (no shade on Lotus they picked the perfect 4 chems, and it's been a huge inspiration for this). Relying on BYO bottles and water makes the sourcing, logistics, shelf life, and food safety 10x simpler, and shipping ~80% cheaper. Adding a single chemical to water isn't that hard (I think?!). A simple web app with recipe saving and sharing would allow people to publish their winners and losers. I'm hoping that by throwing way more darts at the multi-dimensional board, we all discover some new combinations of ions that make particular coffees sing! ## Other Considerations If users are BYOing dropper bottles, they'll probably need to perform a measurement with 100+ drops to find the average drop weight. Web app should have a simple offset for this. From what I can find, all of these chemicals are fairly benign for international shipping purposes and would just require good labelling. I imagine roasteries might find their perfect blend with this kit, then make it en masse for their customers. This is cool, I'd encourage it, and would to keep everything as open source as possible to facilitate it. ## Open Questions - Are these the best chemicals? (is a phosphate option necessary?) - Did I get the math right? - Is there a better option for silica? (it seems promising for mouthfeel so I want to include it) - Should the concentrates be 1mg total per drop, or 1mg of the cation per drop? The calcs above are for 1mg total which feels cleaner. - Is it safe to assume customers have 0.1g scales? Thanks to Samo Smrke, Simon Gautherin, Tom Hopkinson, Liam Wilkie, and Liam Scotchmer for feedback!