As simple or trivial as it may seem, different types of water can have a substantial impact on the quality and taste of your coffee. To understand why, it is important to first learn about the differences among water types and why they affect coffee's taste. Generally, water is classified using its mineral content, pH level, and purification process. Some kinds of water, such as RO and distilled water, are more acidic in nature due to their completely purified state, while others, such as spring water, tap water, and mineral water, are naturally more basic due to the essential minerals that are present. The mineral content of water can have a substantial impact on the quality and taste of your coffee. Using the wrong kind of water for your coffee machine can not only lead to flat, weak, and bitter-tasting coffee but can also cause irreversible mechanical damage in the long run due to corrosion. Therefore, to ensure the best-tasting coffee and longevity from your coffee machine, it is always important to use mineral-rich water containing calcium and magnesium, as these particular minerals can help extract more flavors from the coffee, thereby enhancing the sweetness and body of your coffee drinks. As minerals also reduce the acidity present in water, mineral-rich water helps prevent long-term corrosion of the coffee machine's internal components, such as the stainless steel boiler and copper valves. How about RO (Reverse Osmosis) and Distilled Water? Recently, there has been a new trend of Reverse Osmosis filtration machines for the home market. However, the problem with RO water is that the reverse osmosis process, while good for removing contaminants, also happens to remove the natural mineral content inside your water. Therefore, while RO-treated water is very clean, it loses the essential minerals that are crucial to brewing a good cup of coffee. Similarly, distilled water is another purification process that boils the water into a vapor to remove all minerals and impurities. As such, with the loss of mineral content, RO and distilled water tend to have low pH levels and are more acidic than mineral-rich water. This is why many modern coffee machines are equipped with a water sensor to restrict the use of RO and distilled water and avoid any chance of long-term corrosion damage to the coffee machine's internal components. Why is my La Marzocco water indicator flashing even with a full tank of water? If your La Marzocco coffee machine's water supply indicator is flashing even with a full tank of water, it means that the built-in water sensor cannot detect enough mineral content. In order to resolve this issue, please remove the low-mineral content water and add mineralized water (e.g., natural mineral water, filtered tap water, bottled water, etc.). Is there any way I can use RO water with my coffee machine? The only way to use RO water with your coffee machine is with a remineralizer. As coffee machines cannot use RO water due to high acidity, a remineralizer adds essential minerals into RO water, ensuring that the pH levels are raised back to the necessary alkaline levels for ideal coffee taste. Furthermore, by reducing the acidity, remineralizers eliminate the risk of long-term corrosion of the coffee machine's largely copper and stainless steel internal components. Generally, we recommend clients use mineralized water for convenience. However, if you would like to use an RO system with your coffee machine, please ensure that it has a remineralizer component installed.