If the title seems a bit random, let me explain. Back in May, I began my first real attempts to fine-tune my coffee brewing water, mostly through changing mineral composition. I had previously just followed suggested recipes by the makers of mineralization products (e.g. Third Wave Water, Lotus Coffee Water, Aquacode etc.) which were a good start, but still had minor issues. Now, as a roaster rather than simply a home brewer, my goal was to have a dependable brew water that I could confidently recommend to customers who may be struggling with water-related brew issues.
For those of you unfamiliar with this process and wondering if these coffee nerd antics have gone too far, I wouldn’t blame you. But if you talk to any enthusiast, whether they are home baristas or industry professionals, I’m sure that water composition is among the first few variables they’d list as having the biggest impact on your final cup.
If you’re curious (or a skeptic), my suggestion would be to try a simple experiment yourself at home, with items that can be found in most places. This would just consist of buying a very mineral-heavy water (like Evian), as well as a far softer option (like Aquafina, or even distilled water as an extreme). Try brewing your usual coffee without sugar or milk side-by-side with these two water options and see if you can taste a difference, with all other variables kept the same. Whether one is better or worse is tough to predict, but I can say that there is likely to be a notable difference.
I don’t have a science background, and so I wouldn’t feel comfortable going into a lengthy explanation on why and how each mineral can make your coffee taste better or worse. To provide a very broad generalization, most of this has to do with how hardness and alkalinity levels change due to different mineral compositions - I’ll include some links below in case a more thorough or scientific might help. With these different combinations, some possible effects include:
- More/less noticeable acidity
- More/less cocoa or generic “brown” roast notes
- Mouthfeel (thick and syrupy to thin and tea-like)
- Harder to quantify aspects like harshness, brightness, chalkiness, and finish, to name a few
Of course, these effects are also altered by coffee-specific variables like roast levels or processing (e.g. washed or natural). For instance, I’ve found that “harder” water with more minerals can make natural process coffees taste very harsh, almost like the fruit notes have gone way past the point of sweet ripeness and instead turning into a pithy bitter profile (think ripe oranges vs. biting into an orange rind).
Safe to say, finding an ideal water composition is in my opinion one of the hardest aspects of coffee, whether as a home brewer or as a roaster. For example, what happens if a roaster offers some amazing selections, but customers are not aware of how water can significantly alter the final beverage? In places like New York with great soft tap water, that may not be a noticeable issue, but the same can’t be said if the customer lives somewhere with very hard water. If you consider the sheer logistical and operational effort that it takes to get coffee from the farms to the customer’s table, it can be almost anxiety-inducing if you realize that all of this effort can hinge on something as niche as water. It reminds me of something I read on coffee’s unique journey, in that it is one of the few products where each step of production is independently capable of ruining the final experience. A farmer could be great, but an inexperienced brewer could render all their hard work futile. Conversely, the best equipment would still have a hard time offsetting poor quality control or processing at the farm level, or poor storage conditions during import etc.
Recommendations
So where does all this lead us? After a tedious few weeks of sampling different water recipes, I was able to find a preferred composition that struck a good balance of repeatability and accessibility. I used Third Wave Water’s light roast profile, and diluted it to about 1/3 of its original concentration. The steps are as follows:
- Get a container that corresponds with TWW’s sachet sizes (either 2L or 1 gallon)
- Mix one sachet at full concentration with distilled or 0 TDS water (e.g. a 2L sachet into 2L of water)
- When brewing, dilute this concentration into a 1/3 ratio
o E.g. 300ml of concentrate plus 600ml of distilled water for my 900ml Fellow EKG kettle
I’ve found this to be the best fit for the light and delicate coffees I prefer, and for our roasting style. The softer profile avoids harshness or unwanted intensity, but one thing to look out for is if acidity is too sharp. If so, further supplementing with buffer, through products like Lotus Coffee Drops (sodium bicarbonate) can help tame this acidity without re-introducing the harshness associated with increasing general hardness. One thing to always keep in mind though is that a universal water profile isn’t really feasible, since processing methods and roast levels can differ so greatly.
Shared Experiences, Shared Languages
Asides from finding a composition that I liked (and being shocked at how much softer it was), the most interesting aspect of this entire exercise was how it made me think more philosophically about subjective experiences like taste.
During the same period, I was also in the process of designing Sybil’s packaging. Part of this involved finalizing our color palette, which then had to be communicated via sharing Pantone color codes. Without this reference, it would be hard to guarantee that my perception of “slate blue” would match up with that of our graphic designer, as well as our packaging vendor.
Unfortunately, creating this same shared language is probably one of the trickiest issues when it comes to coffee. Asides from the subjective nature of taste, the vast differences in equipment, brewing methods, as well as water makes it so tough to understand where a problem originates. After basic quality control is done at our roastery, ensuring that there’s no serious green faults or roast defects, it becomes a process of finding this shared language to understand customer feedback, as well as to offer advice on brewing etc.
While it’s still tough to know how best to do this, I do know that it is the most exciting time to be a home coffee enthusiast, with the rapid progression of entry-level / prosumer equipment, the plethora of online resources, and the sheer innovation in regard to coffee processing methods and roasting capabilities. I have no doubt that water mineralization, in terms of both new retail products and general education, will continue to be a large part of this conversation.