Reverse Osmosis Water For Coffee: Pros & Cons!

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Reverse osmosis water is the gold standard for drinking water. It removes impurities such as chlorine, fluoride, heavy metals, and bacteria.

However, reverse osmosis water doesn’t work well for coffee. That’s because coffee beans contain tannins, which prevent the water from filtering properly.

If you want to make the most delicious cup of coffee possible, then you need to get yourself some reverse osmosis water. In this guide, I’ll teach you how to do just that!

Reverse Osmosis Water For Coffee

Water Chemistry:

Several factors affect how water affects coffee. One factor is the pH level of the water. Too high of a pH level will result in a harsh tasting cup of coffee. Another factor is the hardness of the water.

Hardness refers to the concentration of minerals in the water. Minerals can include calcium, magnesium, sodium, potassium, chloride, sulfate, bicarbonates, carbonates, phosphates, nitrates, chlorides, fluorides, and silica.

These minerals can either enhance or detract from the flavor of the coffee depending on the concentrations.

A third factor is the total dissolved solids (TDS) levels of the water. TDS is the sum of all the ions present in the water. Ions are electrically charged particles found in water.

There are two types of ions: cations and anions. Cations are positively charged ions, while anions are negatively charged ions. Anions are usually heavier than cations because they contain oxygen atoms.

Coffee beans naturally contain caffeine, which is a stimulant. However, caffeine is only released during roasting. Therefore, if you use water that doesn’t have enough minerals, the caffeine won’t be able to dissolve properly.

This means that the caffeine will remain trapped inside the bean instead of releasing into the water.

If you live in an area where the water is hard, you should consider reverse osmosis water. Reverse osmosis removes impurities from water, including heavy metals, bacteria, viruses, and pesticides.

But this process requires energy, which makes it expensive. And since it uses electricity, you’ll need to pay for the cost of running the system.

Coffee Water Standards

There are two types of coffee standards: the SCAA Standard and the International Organization of Vine and Wine (OIV) Standard. Both sets of standards are based on scientific evidence, but there are differences between the two.

SCAA Standard:

The SCAA Standard was developed in 1963 and revised in 1985. It lists five specific chemical properties of water that must be met before it can be used to brew coffee. These include:

  • pH – 7.0 to 8.5
  • Hardness – 50 ppm
  • Alkalinity – 100 ppm
  • Sodium – 20 ppm
  • Total Dissolved Solids – 200 ppm

OIV Standard:

The OIV Standard was created in 1990 and updated in 2004. It lists seven specific chemical properties of water. These include:

  • Acidity – less than 0.1 ppm
  • Calcium – less than 5 ppm
  • Magnesium – less than 2 ppm
  • Chloride – less than 1 ppm
  • Bicarbonate – less than 15 ppm
  • Fluoride – less than 1.5 ppm
  • Nitrate – less than 3 ppm

Science Of Brewing Coffee

Coffee is made by boiling ground up coffee beans in hot water. As the water boils off, the oils, caffeine, and other flavorful compounds are released into the water. These chemicals are called soluble solids.

To make the best tasting coffee, you need to adjust the concentrations of three minerals: sodium, magnesium, and calcium.

In order to achieve the optimal ratio of these minerals, you should use filtered water. But if you use unfiltered tap water, you might end up with a bitter taste.

So if you want to brew the best tasting coffee, then either calcium OR magnesium needs to be present in the water.

Science of Water Hardness and Coffee

This article explains how the hardness of water affects the taste of coffee. You’ll find out why certain minerals in water can alter the taste of coffee. And you’ll also learn about the pros and cons of drinking water with high levels of minerals.

Water technology magazine took a look at the 2014 study on coffee and its relationship to water hardness. They found that cations (a positively charged molecule) in water may help pull out some of the aromatic flavors in coffee. Magnesium seemed to enhance the woodsy flavor of coffee, while calcium bicarbonate increased the bitterness. Sodium had no effect on the taste of coffee.

The study did not show that high levels of salt in water affected the flavor of brewed coffees. However, the study showed that softening the water did not affect the taste of brewed coffee.

They recommended combining reverse osmosis (RO) purified drinking waters with regular tap waters, which had some mineral content to potentially enhance the taste.

Using Reverse Osmosis Water to Make Coffee

There are many reasons why you should consider using reverse osmosis (RO) water instead of tap water to make coffee. Here are just five reasons why you should give it a shot.

1 – You can save money

By using RO water, you can save money because you won’t have to buy bottled water. Plus, if you live somewhere where tap water isn’t safe to drink, you can still enjoy drinking coffee without worrying about getting sick.

2 – You can avoid chemicals

Tap water is loaded with harmful chemicals, including chlorine, fluoride, lead, arsenic, mercury, and pesticides. These chemicals can cause health problems, especially for children. By using RO water, you eliminate those risks.

3 – You can reduce waste

Most cities now require residents to recycle plastic bottles. But recycling doesn’t work well for glass bottles. That means that millions of tons of glass end up in landfills every year. Using RO water eliminates the problem of wasting glass bottles.

4 – You can prevent pollution

In addition to reducing waste, using RO water helps protect our environment. Because it removes contaminants from tap water, it reduces the amount of pollutants that enter waterways.

5 – You can improve the flavor of your coffee

If you’ve ever tried to make coffee with tap water, you know how difficult it can be. Tap water makes coffee taste bitter and weak. But using RO water gives you a much stronger, richer flavor.

So next time you’re thinking about buying a new coffee machine, think about whether you’d rather spend $100 on a machine that uses tap water or $50 on a machine that uses RO water.

Benefits of Using Reverse Osmosis Water for Coffee

An R.O. system is an ideal solution if you want clean, fresh tasting water for your coffee. It removes many impurities from your water, including chlorine, which ruins the flavor of your coffee.

An R. O. system from Water- Right provides you with water that’ll keep your coffee tasting great. It eliminates chlorine, which is one of the most commonly used chemicals in municipal water systems.

In addition to being safe for human consumption, R.O. water is also safe for pets and plants.

Pros and Cons of Reverse Osmosis and Coffee

Reverse osmosis filtered water has its advantages and disadvantages when used for making espresso. You should know how to balance those pros and cons before deciding whether or not to use reverse osmosis treated drinking water to make coffee.

The benefits of using reverse osmosed water to make coffee include:

Reverse osmoses are great for making coffee. Not only does it remove scale buildup in your coffee maker, but it removes chlorine and other bad tasting compounds from your water. And since reverse osmosis treats water before it goes through your faucet, it makes your tap water taste great.

Another advantage of using reverse osmosis treated water for making coffee is that it eliminates contaminants like PFAS, Arsenic, and Lead from your water. These contaminants can cause health problems, especially for pregnant women or children.

So if you’re looking for a simple solution to make delicious coffee without any nasty side effects, then you should definitely consider getting a reverse osmosis system installed in your kitchen.

Disadvantages of using reverse osmosis water to make coffee include:

There are several disadvantages to using reverse osmosis water for making coffee.

  • First, it makes the coffee taste flat.
  • Second, it extracts other flavors from beans that many find unpleasant.
  • Third, it increases the bitterness of coffee. And
  • Fourth, aggressive water can damage your coffee maker.

Expert Opinions On Reverse Osmosis And Coffee

Drinking coffee is a personal experience. Some people enjoy it strong and bold, while others love it weak and sweet. Some people like it hot and spicy, while others appreciate it cold and smooth. No matter how you take your coffee, there is no right or incorrect way to do so. It’s just about what you like.

There are lots of different ways to brew coffee. It helps to ask an expert if you’re not sure which method to use. So, I contacted some coffee professionals and asked them their opinions on using reverse osmosis (RO) water instead of tap water.

Barista opinions

There are two main reasons why baristas recommend using reverse osmosis (RO) water instead of regular tap water. First, RO water tastes better. Second, it’s easier to control the pH level of the water.

For example, if you use regular tap water, you may find that the pH level varies depending on where you live. You might be able to drink the water without any problems, but it may cause stomach issues or skin irritations for others.

But with RO water, you know exactly how acidic or alkaline the water will be. That means you can adjust the pH level to suit everyone’s preferences.

Another reason why baristas recommend using RO water is that it makes it easier to control the temperature of the water. Tap water tends to fluctuate in temperature, especially during the hot summer months.

That means that you may end up serving cold coffee to someone else. But with RO water you can easily keep the water at the right temperature.

Regular coffee drinkers say

There’s no doubt that reverse osmosis water makes great tasting coffee. However, there are still plenty of regular coffee drinkers who prefer drinking coffee made with tap water.

So if you’re wondering whether or not you should switch to reverse osmosis water, here’s what expert opinions have to say about it.

Some people say they can taste the difference between coffee made with reverse osmosis water and coffee made with tap water, while others say they can’t taste any difference. Ultimately, the opinion that counts is yours.

If you enjoy the coffee you make with reverse osmosis, then keep doing it. But if you’re not happy with the results and you’d rather drink coffee made with tap water instead, then give it a shot. You might find that you actually like it!


What do you put in RO water for coffee?

To produce good tasting coffee, you need to be sure that your RO system has enough minerals in its output so that they’re available for the beans when they’re ground up.

A specialized filter can help improve the quality of your coffee by adding these minerals to the output from your RO system.

Is reverse osmosis water good for an espresso machine?

Due to its ability for metal leaching and causing corrosion, we do not suggest using distilled or RO water in our machines. However, we do suggest using a water filtration system.

Should I remineralize my RO water to make coffee?

Remineralization refers to adding minerals back into water. It’s done by passing the water through a filter containing small amounts of calcium and magnesium.

Remineralizing your RO water is beneficial because it adds extra minerals to your drinking water, which may improve your health. However, there isn’t enough evidence to say that this practice improves dental health.

What is the optimum TDS level for coffee?

For best results when making espresso, the ideal total dissolved solubles (TDS) level is between 50 and 175 parts per million (ppmp). If the water has less than 50 ppmp, the resulting espresso will taste weak and watered down; if the water has more than 150 ppmp, the resulting beverage will be too strong and bitter.


The water you drink every morning has an impact on your entire day. It affects your energy levels, moods, digestion and even your skin. So when you’re looking for a way to boost your coffee intake, consider drinking reverse osmosis water instead.

This method removes impurities from tap water, leaving behind pure H2O. And because reverse osmosis systems remove contaminants without adding chemicals, you won’t need to worry about any potential side effects.