Hello,
I am currently using Ozarka bottled spring water in my espresso machine, it has excellent taste and the hardness is less than 2 grains per gallon via a Hach test kit. I feel it is actually 1.5 grains or lower per gallon by the way the test kit reacts. My tap water is VERY soft and is less than 1 grain per gallon per the same Hach test kit. However my tap water (well source) has a high iron level and poor taste (according to my wife, I thinks it's ok) which is improved by the refrigerator water filter for ice and drinking. My question is can water be too soft?
Mike

First, defining what is meant by "soft water" - - the standard definition would be water that is lacking in hardness minerals, typically calcium and magnesium. It may have lots of other stuff and still be very soft. Hard water that has been very effectively softened by conventional salt-based softeners would be an example - is very soft but loaded with sodium bicarbonate or potassium bicarbonate.

Very soft natural water would typically, but not always be low in all minerals, not just hardness minerals. Purified water (by RO, deionization, or distillation) is also lacking in all minerals. Water that is very soft and is also lacking in alkalinity is widely frowned upon. Users of RO systems in a plumbed-in machine typically use some sort of remineralization cartridge to add calcium and/or magnesium carbonates back into their water. It has to do partly with taste, but also has to do with making the water less corrosive to the machine.

There are those that believe that hardness minerals are required for tasty extractions. The current recommendations from the 2018 SCA water handbook is that total hardness be above 50 mg/L CaCO3 equivalents. But that's certainly not settled science. On this forum you'll see lots of people who use the "rpavlis recipe", which is the recipe by the late Dr. Pavlis - a chemistry professor and active HB member - who made water with distilled and a small amount of potassium bicarbonate. It has zero hardness and many who have tried it find that it brews perfectly good coffee. Also, if you look at taste tests of softened vs hard water you will find examples where softer water produces taste scores that compare well to to harder water.

* two good examples:
- Jim Schulman's Insanely Long Water FAQ - his taste testing included a low hardness (<20 mg/L) high alkalinity (100 mg/L) conventionally softened water, which fared very well against the harder waters.*

SCA taste study -- you can get an online summary of the study on page 20 of the Caffee Europa magazine - here: http://scae.com/images/caffee-europa/CE61.pdf. Their taste tests of low, medium, and high hardness water with two different coffees favored the low hardness water (around 50 mg/L as CaCO3). They didn't test anything softer than that.

mallen4248 wrote:I am currently using Ozarka bottled spring water in my espresso machine,

You didn't ask, but I think it may be worthwhile to add an opinion about Ozarka spring water. Their currently online water quality report* is nice and complete. It has the following numbers:
total alkalinity as CaCO3 = N.D - 14 mg/L
total hardness as CaCO3 = 8.1 - 22 mg/L
chloride ion = 3 - 25 mg/L
pH = 4.7 - 7.2

The variability probably has to do with having three different water sources. That alkalinity is, in my opinion too low, especially when you consider the chloride I think you have water that might be corrosive over the long run to your espresso machine.

* click the "download quality report" button near the bottom of the page at: https://www.ozarkawater.com/our-springs

Yes, thanks I had already been to the website and read the Ozarka report prior to using. We buy Ozarka Spring water by the 6x1gallon case. Our tap water is naturally VERY soft from a community well system so no need for a household softening system. The caveat is that it has poor taste for drinking or ice unless filtered through the refrigerator particle/carbon filter (according to my wife). To me it's OK and it is fine for cooking. However the water over time does stain the toilets requiring cleaning with a pumice stone. The water report that is available from the community water system is 2 years old and lacking detail. I tested samples of the Ozarka and my filtered tap water with a Hach titration hardness test, the Ozarka gave a result of less than 2 grains per gal, and the tap was less than 1 grain per gal. All things considered, I felt the Ozarka was the lesser of all evils. This being the case which source would you use? I'm not using direct plumb only reservoir. I appreciate the input and suggestions. And thanks for the links listed, I will definitely give them a read.

mallen4248 wrote:I tested samples of the Ozarka and my filtered tap water with a Hach titration hardness test, the Ozarka gave a result of less than 2 grains per gal, and the tap was less than 1 grain per gal. All things considered, I felt the Ozarka was the lesser of all evils. This being the case which source would you use? I'm not using direct plumb only reservoir.

Yes, since you don't know much about the tap water, it may possibly be worse than that the Ozarka wrt low alkalinity and some undesirable chloride.

If you can get the right Crystal Geyser locally that would be my choice. With Crystal Geyser you have six sources and they are each very different - but fortunately you can check the fine print on the bottle to check the source. For soft waters you want something from either the Mt Shasta - Weed CA source or the Salem SC source. Both have low chloride and enough alkalinity to avoid corrosion concerns, and low hardness - should not deposit scale. Lots of people recommend Gerber Pure minerals added water. It's a very consistent soft water, but to my mind has too much chloride relative to alkalinity. For a suitable harder water (which may require infrequent descaling) you can use the CG water from the Olancha Peak CA source. More info related to Crystal Geyser can be found here: Blonding too fast. Profitec 700.

Lots of info also in this thread: Best bottled water for espresso machine


Another option for you with your Ozarka would be to dose it with a little bicarbonate to bring up the alkalinity and the pH. You can make a stock concentrate solution by adding either 8.5 grams of sodium bicarbonate (baking soda) or 10 grams of potassium bicarbonate to a liter of water, then add 20 - 30 ml of that to each gallon of Ozarka which would bump up your alkalinity by 25 - 40 mg/L. ( If you add 38 ml of that concentrate to a gallon of distilled you would have the "rpavlis" water that many folks on this site recommend.

Thanks again for the information and links!