Water for Coffee: The top 3 things our research revealed. 

Hi, Adam sent me a reply to your question: "Looks like your hardness is relatively low, with a good pH balance. From what we’ve learned, it’s particularly hard to remineralize correctly, especially for espresso. As you seem to have a testing kit, you are well placed to do some experimenting - you could try adding Epsom (magnesium-based) salts in controlled doses to a water-filled jug to get the balance right, however this may only be a realistic option for filter coffee. If you wanted to remineralize ‘inline’ with cartridges, then BWT or Puretech both have options, but it’s an involved solution that often overtreats the water, which would be especially true at home. I wouldn’t recommend it. So, in summary - yes, I would leave your tap water alone and just use it! > In terms of differences between espresso or filter coffee - Regardless of extraction method, the balance of minerals in the water affect coffee solubility identically - and we have seen evidence of this in some papers published from various universities (along with some testing we’ve also done!). > Temperature - this is also an interesting one. Without going into extreme detail, we’ve found 96C to be a good extraction temperature. Do you need to invest significant time and money to make sure it’s exactly 96 (again, which it seems like you have!)? No, not really - you can get excellent extractions in the range you mention. Taste dictates best here! Hope this helps!, Adam" ...Thanks for the questions, Ben

@@SevenMilesCoffeeRoasters Thanks for the info again guys! I'm definitely keen on playing around with epsom salts for filter coffee. Might as well make use with all this time at home now lol. Stay safe :)

I have the same problem. Thanks for the answer.

The proper way to remineralize (for espresso) is with potassium bicarbonate which is incredibly solvable in water meaning it won't ever scale, neutral in taste compared to some other salts and unlike sodium chloride it will actually have a balancing effect on the acidity of shots. They should have put it in the study instead of the nonsensical sodium chloride.

ty 🙏🏼

Have been using third wave for many years and it's great.

According to James Hoffman do not use distilled water

​@@stephenshanebeaty Distilled water plus Third Wave (or similar) is what Hoffman recommends.

a simple carbon filter will remove the sediment, odor, chlorine, etc without having much effect on the minerals that effect extraction (like magnesium & calcium). These filters are generally a good starting point.

excellent, thank you very much

I've never heard of a water not tasting very "well." Wellness has to do with health and I'm not aware of any water described as "well" unless it's well water. Perhaps you mean the water does not taste very 'GOOD."

I wish they would answer this one as I live in a very humid area and find this very interesting! I’m just getting into the whole expresso at home experience. I actually haven’t bought a machine yet because I’m trying to learn all I can. At first all the info was so overwhelming that I gave up on the idea for awhile. But I’ve decided to approach it slowly instead of trying to learn it too fast and making a rash purchase then regretting it. I had not thought about humidity effecting it so I am curious as well. I’d love to know which machine or method you use?

Chlorine is an element, symbol Cl; its presence in water would typically be as a dissolved (and highly corrosive and poisonous) gas. Chloride is a chlorine ion, that is a chlorine atom that has acquired an 'extra' electron and is not in that form particularly poisonous or corrosive as the chlorine it comes from.

Hi JK, Ben here. I'm not a chemical engineer, so I hit up our coffee science team for some advice. We work with commercial systems, so some brands mentioned may or may not be practical in your situation. Here's what they tell me: "Chloride at 40ppm is acceptable (La Marzocco recommends 30, but it is not worth the trouble to install reverse osmosis filters). pH is low, may cause corrosion (main problem). Water is soft, would assume low lime scaling potential. For this scenario, cartridges that raise pH (like BWT BestProtect, BWT BestMin) may help. But BestProtect will strip all remaining hardness, and BestMin may raise hardness too high (but still better than corrosion). Filters which reduce corrosion and don’t change constituents in water like Puretec Balance+ would be ideal. Reverse osmosis filters can be used to reduce chloride (and everything else), but do note of its cost ($2000+) and space it takes. In this case, you need a remineralisation filter after RO (blending is not recommended since it does not solve the problem of low pH, which is the main concern)."

Seven Miles Coffee Roasters Hi Ben, wow thanks so much for forwarding that information! I own a GS3, and I'm glad to hear that my tap water is more or less okay. I agree my water may be a tad too soft, after filtering. When you mentioned the blending, did you mean blending RO/distilled water with remineralisation powders (like Third Wave Water)?

Blending refers to mixing of tap water with the filtered water to make a mixture (usually a T-junction with an adjustable valve), essentially ‘watered-down’ tap water. This only works for places where the tap water is hard, balanced pH etc., which doesn't apply to your scenario.

I know I'm years late to the party, but a safe and simple way to increase pH is to add sodium hydrogencarbonate, better known as sodium bicarbonate or baking soda. As the latter name implies, it is commonly used in baking and is thus obviously non-toxic. It is highly soluble in water, so it will not cause scaling. Even a concentrated solution will only reach pH 8.3, which is within the pH range considered safe for drinking water by WHO, so there is no risk of harming yourself or your coffee machine by adding too much.

Distilled water is not ideal, as the coffee won't extract as well without a small amount of minerals. You can do a quick comparison by blending some filtered tap water (or spring water) with the distilled to see the impact in flavour on the blend you're using.

Yeah you are missing out, without "hardness" minerals your coffee will be acidic and especially lighter roasts will be basically unworkable for espresso. Easy way to solve it is adding potassium bicarbonate which will offgass CO2 when brewing (more crema) and neutralize the unnaturally sour taste from destilled/RO water and protect your equipment from the corrosive effect of very low ppm water. A kilo for 10 bucks will last you a lifetime at around 0.1 grams added per liter for most roasts, a bit less for very dark roasts and sometimes quite a bit more for very light ones (which would otherwise not be very well suited for espresso because of the sour shots)

I concoct my own water because the sediments in our tap water are revolting. For use in my CPAP machine I have been distilling it. For humidifier use - without leaving scale - it is fine, but for coffee I buy the 5 L demineralised or distilled water instead to start. Learned from barista sites how to bring its mineral content up to be optimal for espresso - by adding bicarbonate soda and Epsom salts in measured proportions to two calibrated solutions and then using easily measurable quantities of these “standard” premixes (100 ml each) diluted up to 2 litres with distilled water. At the ratios I created I only need to get out the scale to make the calibrated solutions every other month, so it is not much of an overhead. I always have a ready source to refill my De’Longhi semi automatic machine. Having dialled in my espresso on the machine (grind, amount, pressure etc) after changing a roast or bean type I get a good crema, good tasty extraction and repeated outcome I can rely on every time. For reference concentrations I used “Rao’s water” recalculated to my container sizes. Your palate of coffee or water recipe choice may differ, but that is how best use distilled water and completely avoid any scaling issues in the machine. Now used it for 18 month and no sign of scale at all, but the recommended regular cleaning of the pump device is important to maintain the taste. Good luck!

Easiest and cheapest thing for you to start doing is: first get a _ZeroWater_ pitcher and put DISTILLED water in it. Here's the logic: distilled water is usually in plastic jugs which can/will give weird flavors (e.g. plastic) but will be neutralized through the _ZeroWater_ pitcher while, in theory, never clogging up your _ZeroWater_ pitcher's filter because distilled water is nearly 100% devoid of solids already. Result: zero TDS, non-plastic flavored water, and you save money because you only need to change the _ZeroWater_ pitcher IF it fails to remove bad flavors. Okay, now you've got a really good base to start experimenting... Assuming you have a TDS meter (which, to be fair and without getting too technical, is just a _guide_ - tool. See the Specialty Coffee Association's wonderful article "Addressing Water Quality Issues: The TDS Meter" if you want a deeper dive) begin mixing your pure water with your tap water. Maybe start at "extremes" like 75ppm then 150ppm and dial in, through trial and error, what brews best for you. It's fun. If you want to avoid scaling in a machine, I'd recommend staying below 100ppm - more like 80 - 85 or lower to be safe. If I had to guess, your water is WAY too high in a particular mineral, causing the flat taste. Too many carbonates (e.g. from calcium carbonate or sodium bicarbonate), from my experience, causes a "chalky", flat, taste, I think. Soon I will be experimenting with Third Wave Coffee mineral sachets to see if it's better than doing process as described above. I use well water also. Got rid of our old salt-based water softener system. Personally, I wouldn't worry too much about pH, at this point. 7.5 is fine. Understand that unless you have a machine (e.g. an ionizer type like I own) that can change the pH without chemicals; your water's pH is determined from whatever is IN the water i.e. a solid or gas (like CO2). And, other than what's noted in the video, as far as I know, the most practical use for pH in coffee water is to tweak how the coffee's acidity is perceived. So, an 8.0 pH water might tone down that acidity a bit, producing a sweeter cup. Best Regards

Hi David, Ben here...I asked our coffee science team about your question. They tell me there are 2 options for RO systems: "1) Adjustable bypass can be done where the filtered water is mixed with tap water (should already be treated by the pre-filter) to achieve the desired water quality. For example, tap water has 200ppm of TDS, and assuming filtered water achieves 0ppm of TDS, with a 25% bypass (mixed with 1 part tap water to 3 part RO water), the final water would result in 50ppm of TDS. 2)The more expensive option is to install a remineralising cartridge, where the cartridge will introduce minerals into the filter water. These cartridges do deplete, make sure you check the capacity and be replaced accordingly."

@@SevenMilesCoffeeRoasters Wow I had no idea. So definitely I think for my scenario I would have to start with the option 1 first until I can get a filter in the plumbing. Thanks so much for the clarification.

@@SevenMilesCoffeeRoasters Hello there. I added an alkaline stage to my RO system. The filter adds between 8 and 9 pH. A little outside your recommendation, but is it still safe for the espresso machine?

Yes, totally (see their answer to Mr Meeseeks in the comments)

@@dlevi67 so i understand I could prepare distilled water with only mg or ca and no Na yielding 60 ppm? or would you always add some sodium?

@@vizzo7 Well... the sodium question is controversial. It is something we taste as 'salty', and I don't know about you, but I don't particularly like salty coffee. On the other hand, some people feel that having _a little_ sodium in the water improves the flavour. In either case, in addition to Mg and Ca you also need some source of alkalinity - which is where the 'sodium' usually comes from, as sodium bicarbonate is a cheap, easy-to-find source of alkalinity (and sodium). If you don't like the idea of 'more sodium in your diet', I would point out that usually we are talking of a few mg/l - and unless you drink litres of coffee a day, this is unlikely to be a significant source of sodium in your diet; if you want to avoid it in any case, potassium bicarbonate is also cheap and easy to find. Introducing alkalinity without bicarbonates is also possible, but it's more complicated/expensive and possibly not improving taste as much.

@@dlevi67 well actually I don't care about my diet but my question is if I can get good results only using Mg sulfate or Mg chloride or calcium chloride

@@vizzo7 The short answer is no. You need a source of alkalinity, which none of those provide. Chlorides can also be corrosive - particularly if your machine has a copper or brass boiler I wouldn't use them.

He spoke about pH, that is alkalinity. The higher the pH the higher the alkalinity. The lower the pH the higher the acidity.

​@@gray_gogyPH and alkalinity are not exactly the same. Google 'ph vs alkalinity'. All this water science is so interesting 🤗

You seem to be misunderstanding what the points made here were. 1. There is still partial pressure from the released/dissolved CO2; whether that's enough to "hold up the puck" or that was just a figure of speech does not change the fact that one would expect solubility (i.e. "extraction") of other compounds to be slower - though ultimately end up at a higher overall concentration - if more CO2 is released (for whatever reason - e.g. neutralisation of K/NaHCO3). The graphs that they put in the video did not show the rate of reaction; they only confirmed that extraction increases with pH. 2. Concentration of CaCO3 > 60 ppm in tap water is a common occurrence in many parts of the world. Most of Southern and Eastern England is well above 250, for example, and it's really hard to find bottled water from anywhere below 100 ppm (Ca + Mg CaCO3 equivalent). The point is that - again - above 60 ppm there is a marginal benefit to extraction of the 3 compounds measured, but below there is a significant loss. Totally demineralised water is not good from that point of view. 3. They didn't use NaCl to modify acidity anywhere. They checked whether "total dissolved solids" (which I'm taking to be analytically defined as dry residue at 180 C) have any impact on extraction of specific compounds. They don't, at least at concentrations that for NaCl are undetectable to taste (i.e. ~500 ppm) 4. Nobody here said anything for or against the choice of KHCO3 vs. NaHCO3 as alkaline buffers; they simply didn't do that test (or at least they didn't report it). Some solid criticism would do the world of science good, but yours is not it.

@@dlevi67 1: No, Dissolved gasses are not ionic compounds, they do not affect solubility of other compounds in that manner 2: No, excess concentration in tap water is irrelevant for the purpose at hand, increasing temperature causes excess ppm to drop out very quickly. 3: No, The salt thing is nonsensical 4: Yes, which is absurd since it's supposed to be a a scientific investigation of water quality for coffee, they leave out the most important modifier but qualify ones that have no actual effect beyond calcifying your boiler. Lol, I supposed someone wrote something like that to you because you write comments like yours, have a cracker Poppy.

@@srolesen You clearly have no idea of what you are talking about (or chemistry, or physics), starting from understanding that this is not a scientific investigation of "water quality for coffee". It is a study about what factors influence solubility of certain compounds found in coffee. And what is in your opinion "the most important modifier" that they left out, go on, I want to have a laugh. You should stop smoking whatever you are smoking, kid