One of the most common calls we get is people asking about what kind of water is best to use in their machine. A very good question, as we’re all certain that the customers who call, and ask about the water want to protect their investments. There are basically three ways you are going to get water for your machine: from the tap, from the bottle, or a filtered water source, such as a reverse osmosis filter. All of them have their pros and cons. Let’s look at them, and what it means for you maintenance wise.
Water from the tap is a fine option to get water for your machine. If you live in a major city, the water is cleaned before it gets to you, but not ultra purified. You may want to put it through a Brita or Pur filter to clear out any large particles, but tap water is not an enemy of the espresso machine. In fact, you may even prefer tap over the other two, as you are used to the mineral content and percentages in your tap water already, and believe it or not, that affects the flavor of your coffee. The amount of lime or calcium in the water acts as a tapestry for the coffee notes to kind of bounce off of. i.e. a shot from the same espresso beans in Rochester, New York will taste different than a shot from Vancouver, Canada because the mineral content in the water is different.
You will need to assess how hard your water is, to determine how often you will need to descale, though. Ideally, you want it around 50 ppm (parts per million), or between 1 and 3 gpg (grains per gallon), depending on which hardness scale you use. The upside of using tap water is it will enhance the coffee you drink with a familiar taste. The con is you will need to identify the proper intervals keep to your schedule with regards to descaling the machine.
Bottled water comes one of two ways, either distilled or spring water. These two are at the opposite ends of the spectrum, as far as how the coffee will taste coming out of your machine. Spring water is bottled at the spring, and usually has a fairly high mineral content. This is one reason a lot of people like their Poland Springs or Fiji waters. Similar to tap, you will need to test the spring water to get an idea of how hard the water actually is and keep a regular descaling schedule, so that the machine doesn’t get a large build up of scale.
Distilled has almost zero minerals in it, which virtually eliminates the need to descale the machine. I emphasize virtually, as you still want to keep the machine clean and running well. If you use distilled water, I would still recommend a twice-a-year descale, just to keep the machine clean and eliminate any bit of scale that may have been let behind. The pros of using distilled water would be the flavor, and if the tap in your municipality isn’t that great. Also, if you run well water (some of the hardest water known to man) distilled water is a great solution. Distilled water has the same cons as tap and spring water, also it isn’t ideal for use in Prosumer level machines (more on that below).
Filtered water, via reverse osmosis system is the purest water available—which may be what you want to use, or even what you already have in your house. It will eliminate the need to descale, but can actually damage some machines. If you have a larger machine or any machine in the Prosumer Class, you should not use reverse-osmosis-filtered water; it is so pure, that the water takes on an almost acidic quality and leaches ions from the boiler. Also, without any mineral content in the water, the machine won’t realize when the boiler is full. Most espresso machines have electrical sensors at the top of the boiler to determine if the boiler is full or not. Without minerals to conduct the current, the machine thinks it needs more water, and will continue to pump water into the boiler. What we recommend mixing a portion of tap or spring water in with your reverse-osmosis-filtered water, or even adding a small bit of salt. I know, it sounds funny, but if you add a pinch of salt to a gallon of water, you won’t taste it, and it will solve those problems, and keep the internals of your espresso machine really clean. The upside is that the internals are kept clean. The cons are that there are no minerals, meaning no interaction with the coffee “notes,” and possible damage to the machine.
In most espresso machines, filters are a nice addition. Some of the prosumer level ones have water softeners that you can add in the tank, and a lot of the super-autos have water softening or purifying filters that you can add in the reservoir. The JURA machines even claim that if you use their purifying Clearyl filters, that you won’t need to descale. Ever. Personally, I would still descale a couple times a year, in between filters, just to be safe.
I hope this helped shed some light on how important water is to the machine you love and gives you a course of action on how to keep its guts clean for years to come. Nothing is worse than when you get a call from a customer hearing that their machine that isn’t even 2 years old is leaking like a sieve because they never descaled.