Tap Vs. Bottled Water for Coffee – Which is Better?

Last Updated on January 16, 2022 by John Moretti

While many people may consider themselves experts in creating the perfect cup of coffee, it is surprising how often water is overlooked as a component which can make an enormous difference.

Seeing as coffee is pretty much 98% water, it’s unsurprising that the water can make a difference to the coffee. How exactly the water makes a difference, however, is determined by numerous factors, many of which come down to reasons of chemistry.

Whether bottled water or tap water is better for your cup of coffee is determined by the water itself. While some bottled waters are suitable for coffee-making, others are not. While some tap water is ideal for making coffee, the tap water in other regions makes for terrible coffee.

In order to understand which type of water is best for your coffee, you will have to understand how the water and its composition actually make a difference to your coffee.

Tap Vs. Bottled Water For Coffee

Tap Vs. Bottled Water for Coffee

The thing that determines the flavor of your coffee is how the mineral composition in the water reacts with the coffee itself. There are good interactions and bad ones, but these also depend on your personal taste.

  • The pH of the water, (i.e., its acidity/alkalinity levels) as well as the Total Dissolved Solids, play a major role in not only determining how the water tastes, but in ultimately determining the flavor of the coffee.
  • The Total Dissolved Solids refers to the composition of different dissolved substances in the water, as well as a relatively low amount of inorganic matter. The dissolved substances include, among others, calcium and magnesium.
  • The ratios of calcium and magnesium determine the flavor of the coffee, as the presence of magnesium enhances the flavor of the coffee. This is because the magnesium sticks to the compounds of the coffee, thereby giving it a smooth and enjoyable taste.

How Water Hardness Influence Limescale Build-up in the Coffee Machines

limescale build-up

Tap water – often cause limescale build-up inside your coffee machine, which is why most coffee machines advise that you “descale” the machine every so often in order to ensure that the machine does not become overrun with limescale.

Bottled water – often does not contain limestone, which means that the use of this type of water would entail far less build-up and therefore far less need to clean the machine as frequently. Limescale build-up will not only affect the flavor of your coffee, but it will also start to destroy the coffee machine from the inside if not taken care of properly. 

How Water Influecing Coffee Flavor

coffee flavors

The flavor of bottled water is most often highly neutral. It means that on a basic level, the flavor of the water will not interfere with the flavor of the coffee. However, some bottled waters can make for dull and lifeless coffee due to the processes they undergo.

It’s important to understand what causes water to create different flavors within the coffee, as you will then be able to understand which types of water will go best with your coffee of choice.

Why Water Hardness/Softness is Important for Coffee

Water hardness is determined by the TDS (Total Dissolved Solids) present in the water. This is an extremely important factor in determining the flavor profile of a cup of coffee. The water softness or hardness refers, in fact, to the ion concentration in the water.

measuring water hardness

The most significant ions, in this case, are magnesium and calcium.

  • Hard water has a higher concentration and usually overpowers the flavor of the coffee. Check our guide to the best coffee makers for hard water.
  • Soft water has a lower concentration and makes for a less flavorful cup. Balance is key. Soft water is also prefered for most capsule coffee makers like Keurig.

There is a group called the Specialty Coffee Association. They have a number of water standards which show that the ideal characteristics for water to have are the following:

  • no odor
  • no chlorine
  • a pH of 7.0
  • alkalinity of 40ppm
  • calcium hardness of between 50 and 175 ppm
coffee and water

Essentially, what this means is that the ideal water for coffee is clean water which falls on the softer side of the scale, and it has no chlorine in it whatsoever. This is why the presumption that bottled water will make for better coffee is not entirely true. 

This is due to the fact that while bottled water contains no chlorine which will improve the coffee’s flavor, it will either usually have high levels of minerals (making the water hard) or a low concentration of minerals (making the water soft).

High levels of minerals can overpower the flavor of the coffee, while no minerals at all will make for an exceptionally dull and flat cup of coffee. The best water for coffee contains small amounts of minerals which bring out the best possible flavor in the coffee.

Best Bottled Water For Coffee

what is the best bottled water for coffee

There are numerous types of bottled water on the market, but not all of them are good for making coffee. This is because not all bottled water is the same. Some are spring water, while some are distilled. These all have varying levels of minerals in them, which significantly changes the flavor of the coffee.

There are a few bottled waters that fall in the “correct” range for making good coffee, and these are not so easy to find. In order to find a brand of water that will make for a good cup of coffee, look for a TDS level of between 50 and 157 mg/l. 

There is a brand that comes highly recommended called Volvic, and its minerality is at a level of 130mg/l. It has a neutral pH and is bottled at the Clairvic Spring in France. The natural filtration of this spring water happens as a result of a bed of lava rock located near the source.

This results in spring water with balanced minerals with calcium and magnesium in moderate amounts. This helps to balance the acidity of the water, helping to create the closest thing to a perfect cup of coffee.

Crystal Geyser Alpine Spring water is bottled in the United States at numerous natural springs, protected by law. This water also boasts a neutral pH of 7, with a softer minerality and a TDS range between 90 and 110 mg/l.

Similar concentrations of magnesium and calcium help to create a balanced cup of coffee.


While there is no hard and fast rule for knowing which type of water is best for your coffee, it is hoped that with this knowledge in hand, you will be better equipped to understand why your coffee might not be tasting its best, and you will know how to adjust this.