Drinking water - Is it really that borring?

Drinking water – is it really that boring?

Many people think so, and we often hear that water has no taste and that it all tastes the same. When we say that, it is often because in Denmark we are fortunate enough to have some of the cleanest drinking water in the world. This means that, in the vast majority of cases, we drink tap water and the common brands of mass-produced water in the supermarkets. 

If we look further south in Europe, it is a very different story. Here, more different kinds of water are drunk, and bottled water is often consumed the most.

In short, different types of water have different tastes – but unlike e.g., beer and wine, it is more difficult to taste the difference between water as it is the subtle nuances that give water its different-tasting notes.

There are different classifications of water in relation to its the mineral content. These minerals give water its taste, meaning that the fewer minerals are in the water, the less taste it will have, and the opposite is also true – so, a greater amount of minerals will make the water taste   stronger.

In Denmark, it has been concluded that the water we drink the most of has a mineral content between 200 and 480 mg/l, even though there are several types of water with mineral content from 0-13,000 mg/l.

What causes the different tastes in water?

When water has different tastes, it can be linked to why wine from different regions tastes different even though the same grape is being used. The difference in taste is due to what is referred to as terroir. Wikipedia explains quite well what terroir is:

Terroir comes from the word, terre, which means soil. It was originally a French term in wine, coffee, and tea that indicated the particular traits with which geography, geology, and climatic conditions at a specific location characterized certain varieties. Farmland in the same area shares the same soil, weather conditions, and cultivation techniques, which all contribute to the unique qualities of the harvest. The same grape variety, when grown in different regions, can thus produce very different types of wine. (Source: Wikipedia)

So, terroir means that the surrounding geography and geology have their very own influence on how the wine tastes, and this also applies to water.

Basically, how water tastes depends on where we are and what surroundings and conditions the water has had. A good example of a specific terroir is in Greenland. Here, large amounts of rainwater freeze at the surface and thus do not come into contact with the mineral-containing subsoil. Hence, water from Greenland is often very low in minerals. In Denmark, a different terroir exists as the Danish subsoil is very calcareous. This means that the water absorbs the taste of chalk and thus has a different taste than what you would experience in Greenland. Therefore, the conditions under which the water was ’created’ are crucial in relation to how it tastes. 

The minerals in the water As mentioned earlier, minerals help give the water a taste. Natural water, mineral water, and spring water have three types of minerals that are called cations. If there is a sufficient amount of these, it is relevant to how the water will end up tasting. The taste can be sweet, sour, bitter, or salty – depending on the amount of the specific mineral in it. The three cations are the following: Sodium Na+ Calcium Ca2+ Magnesium Mg2+

Compound minerals

In addition to sodium, calcium, and magnesium (cations), there are three other minerals known as anions. When anions and the three aforementioned cations bond together in a chemical reaction, new substances can be formed that help give water its taste.

The three anions are the following.

A chemical reaction can happen between the cations and the anions that bonds them together and thereby forms new minerals – which again can change how the water tastes.

In the table below, we have put together some of the most common substances that form when one of the three cation bond with one of the three anions.

In order for these compound minerals and uncompounded minerals to give the water a taste, they must reach a given threshold value. If the value is below this, you cannot taste the minerals.

Is it easy to find information about minerals and the mineral content of water? Yes – usually, especially when you look at the slightly better products, as the manufacturers are often good at providing information about the mineral content of the water. If the product is called mineral water – the mineral content MUST be stated, whereas for spring water and packaged water, the same rules do not apply. Most high-end manufacturers want to disclose the mineral content as it may determine whether their product is purchased by the buyer in the market.

The information found on the bottles will often include cations and anions. These will be shown in mg/l (milligrams per litre). In addition, there is usually information about how large the total mineral content is. This will be stated in TDS, PPM, or in what is called a dry residue 180 (drying test).

TDS: Total dissolved solids. This is an expression of how many dissolved minerals are in the water. TDS is expressed in milligrams per litre (mg/l).

PPM: Parts per million. You sometimes see that the TDS level is not mentioned as mg/l, but rather as PPM. But these two mean exactly the same thing, which thus means that a TDS of 55 mg/l is the same as 55 ppm.

Dry residue 180: This is a drying test in which you heat the water to 180 degrees Celsius until the water has evaporated. All that remains are the minerals as they do not evaporate. Then, the minerals are weighed which leads to the figure for Dry Residue 180. The figure is in mg/l.

pH level

Besides the fact that the water can have a taste that is decided by cations and anions, the pH level also has a say in this. The water can have a sour, sweet, or bitter taste depending on where it falls on the pH scale.

The pH scale ranges from 1 to 14, with 7 being neutral. Anything below 7 is considered acidic and anything above 7 is considered basic.

The pH scale is logarithmic, which means that a difference of 1 will be equivalent to increasing the acid or base content by 10. This means that if the water has a pH of 5, it will be 10 times more acidic than water with a pH of 6.

If it matters to you whether a specific type of water goes with a specific type of food, the Fine Water Society has made a small guide. This is often used at fine dining restaurants where water is not just water but needs to suit both food and wine.

Aroma in the water

As a starting point, water should preferably not have a smell. If that were the case, it would not be pleasant to drink. If water has a smell, it could be due to several different reasons. What they have in common is simple – they should not be there! The smells may come from several sources such as detergents used in recycled bottles or chemicals from plastic bottles. It is rare that the water itself causes the smell.  

Water hardness

In Denmark, we know all too well about hard water. We see it in large parts of the country where lime is a big part of our drinking water. The hardness of the water is an expression of the presence of magnesium and calcium. Hard water can have a thicker consistency and, in some cases, it is visible to the naked eye if you have a glass of hard water and a glass of soft water. The difference in the consistency of soft and hard water can also be felt when drinking it.

In Denmark, we primarily measure the hardness by using Deutsche Härte (°dH), which is the German hardness measurement. One degree on this scale means that the water contains 10mg dissolved calcium or 7.19 dissolved magnesium per litre.