Water, The Forgotten Ingredient in Coffee

Water And Coffee

Little is known about the nature of water in order for professional and home baristas to achieve the best possible result in the cup. If you read about the modern way of preparing coffee and coffee specialties, you will learn a lot: about types of coffee and their origin, roasting and grinding as well as about the preparation, the machines that are used and their features, their operating parameters, etc.

One ingredient that is represented with over 98% in a filter coffee and around 90% in an espresso receives far less attention: water, the universal extractant for coffee. Little is known about the nature of water in order for professional and home baristas to achieve the best possible result in the cup. One thing should be said in advance: our water in Germany is good. It is an important food, if not the most important of all. Well examined and monitored, it arrives in excellent quality at home or in the respective coffee bars, where we can use it without hesitation and without thinking about it.

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By the time it arrives at home, the water has a long journey behind it: from the clouds from which it rains, it finds its way through the earth and rocks until it finally ends up in our coffee machines and coffee cups after being treated at the local waterworks. And along the way, water, which is an outstanding solvent, absorbs a lot. A multitude of substances can therefore be found in our drinking water. These include natural substances such as calcium or magnesium and carbonates, sodium, potassium, iron and chloride, but also anthropogenic that get into the water as a result of interventions in the environment, such as excessive iron and chloride, or sulfide and sulfate.

In addition, there are also particulate substances such as sand or rust from the pipe network as well as organic components or chlorine or Hypochlorite in drinking water. In addition, water has the property of being acidic, neutral or alkaline, which we can measure and record as a measure on the pH value scale. All of these accompanying substances in the water, for example, the formation of lime, have an influence on the machine technology.

But also on the quality and taste of our coffee extracts, which have been produced with great care. This means that we not only have to protect our machine technology from the formation of limescale but that we should also keep an eye on the sensors. Anyone who seriously produces coffee specialities, whether at home or at work, knows that they have to protect their expensive technology with water filters, from limescale that forms primarily on the hot surfaces of boilers, heat exchangers and heating elements.

Special ion exchangers in water filters primarily remove calcium from the raw water and thus prevent lime from building up in the form of calcium carbonate and from sticking to machine parts as a so-called scale.

Because that hinders the heat transfer and causes malfunctions in valves or pumps, which leads to costly repairs. Other unwanted components can be removed with fine filters and organic compounds, as well as chlorine with activated carbon. 

Water filter manufacturers have taken on this topic and developed special multifunctional filters with which machines can be perfectly protected from normal lime and other foreign substances.

However, the permanent hardness is much more unpleasant when there is sulfate in the water and it precipitates in the form of gypsum in connection with calcium and attacked the coffee machine.

In contrast to normal lime, it stubbornly defies the cleaning processes that are routinely carried out in many coffee machines. Also for this special gypsum problem, which occurs very often, there is a special filter that offers good protection against the dangerous permanent hardness.

Limescale protection and filtering the water are only one side of the coin. Baristas, however, are primarily interested in taste and the sensory experience when serving their creations. 

On Amazon, you can find some absolutely great water filter pitchers, that I personally use. You can see the best ones here on this link to Amazon.

Cem Korkmaz, Austrian master barista 2011 developed a cupping water experiment for BWT water  (Best Water Technology) + more and carried out several tastings at the championships in Berlin. Cem Korkmaz used one and the same coffee with identical parameters such as grinding, temperature and extraction time for brewing coffee for cupping manufactured. He only changed the water quality. 

Different types of raw water from Berlin (medium hardness, high sulphate content), Wiesbaden (medium hardness) and Würzburg (very hard water) started. At the same time, foreign smell and taste were removed from the water with a BWT besttaste filter, but without changing the water hardness.

A total of around 100 testers, from professionals to hobby barista, took part in this cupping tasting. 

The coffee extract is fed to the taste buds on the tongue and palate to develop the taste or is mixed with air by intensive sipping, whereby the volatile aromas reach the receptors in the nasal cavity.

Practically all testers were able to determine the striking differences in taste and aromas, depending on what water was used. 

The coffee testers found the coffee to be most harmonious when it was made with Berlin raw water that had previously been optimized with water filters. This filter removes calcium, the limescale builder, in exactly the right amount and with suitable pH value, so that flavours and aromas can develop unhindered.

In addition, the unwanted calcium sulfate (gypsum) is specifically removed from the water. 

In general, the quality of the coffee was rated significantly better after a targeted optimization of the respective raw water. There were deviations in all untreated raw water. The coffees made with it were more or less off-flavour because they either tasted too stale or the bitter substances came to the fore in an unpleasant way.

But what was even more astonishing was that all coffees tasted and smelled differently depending on the type of water, even though they were made with the same coffee. A possible explanation for this phenomenon: If there are an extremely large number of components in the water, i.e. is it very hard or the pH value is acidic, the bitter substances dominate, which are extracted disproportionately in this milieu.

In addition, there is a blockage of flavour and aroma substances in coffee because they “bind” calcium and can therefore no longer trigger the desired sensory stimulus on the tongue or in the nose.

If you have too few minerals in the water, the flavour carriers are missing and it tastes bland. If the pH value of the water is not optimal, the acidic notes from the coffee can come into their own, cover up some of the finer taste notes and prevent the development of volatile aromas. Once you have “tasted” these findings like the coffee testers at the Barista Championships in Berlin, every professional and home barista will only become clearly aware of the importance of water for their own creations. 

It, therefore, depends on the right water optimization, which on the one hand reduces the lime content in order to protect the coffee machines, but on the other hand, also leaves enough minerals in the water for a perfect coffee.

So water filters are needed that bring the water into the necessary balance.

The barista’s 6 Key Notes.

These six factors affect the taste of coffee:

Which coffee mix is ​​used in the preparation?
Quantities :
How much ground coffee (in grams) is being processed?
Which machine is in use?
In what condition is the water used?
How well does the barista know about the subject?
Grinding degree:
How fine / coarse is the coffee ground?

Water features

Coffee would not be possible without water. But what role does water play in the development of taste? We got to the bottom of the water for you once more. Find out why good coffee deserves the best water and how you can optimally prepare your water.

The water has an enormous influence on the aroma and taste. It is not just the easily measurable factors such as hardness and pH value, there are also the numerous chemical substances (minerals) contained in the water in different concentrations, chlorination, the material of the respective water pipes or the duration of the water usage in the lines, which can have an impact on taste and aroma. 

With the same measurable water values ​​and identical preparation, the same coffee can taste significantly different due to the other factors; 

And when using water that is sometimes very soft and sometimes very hard, it can happen that coffee can only be identified as one and the same by experienced tasters.

Good coffee water should always be fresh and rich in oxygen. It, therefore, makes sense to only use cold, not stale water for the coffee. This water should be heated as quickly as possible so that as little oxygen as possible is lost during the heating time. 

Therefore, please do not take warm water out of the tap and then boil it. If no water has been removed from the line for a long time, e.g. B. During a vacation, it is not advisable to use the first water drained out to prepare coffee. 

Even water that has been unused in a fully automatic machine for several days is unsuitable for the full taste development. It does not help much to empty the water tank, because depending on the machine type, some of the water always remains in the boiler.
The most well-known and perhaps the most important factor influencing the taste of coffee is water hardness. But how does “water hardness” come about and what does it mean in detail? 

Rainwater flows from the surface through the soil and collects as groundwater. It depends on the nature of the soil to what extent which substances are released from the soil. 

The higher the proportion of calcium and magnesium that the water absorbs on its way through the soil, the harder it is. Strictly speaking, water hardness is a measure of the amount of minerals dissolved in the water as ions, especially the vital minerals calcium and magnesium. Good coffee water can be rich in minerals, as the minerals and salts contained in the water are also flavour carriers.

The softer the water, the fewer limescale deposits there are on household appliances and the less detergent and washing powder is required. Soft water is found mainly in regions with granite, gneiss, basalt and slate. 

Hard water, on the other hand, causes the equipment to become calcified and requires a higher consumption of detergents and detergents. 

Limescale deposits in the water pipes, however, protect the metal from corrosion. Hard water is prevalent in regions with sandstone and limestone; hard water can neutralize the fine acids in coffee and give it a flat taste. 

This effect is stronger the longer the contact time between water and coffee grounds lasts. The result is then – despite the long contact time – a little aromatic and flat coffee.

A tip for hard water: after boiling, let the water stand for a few minutes and, depending on the degree of hardness, boil it up once or twice again. 

Despite the loss of oxygen caused by this, the coffee gains a distinct taste due to the precipitating lime. Or add a tiny pinch of baking soda to each cup (available in any grocery or supermarket for a few cents). But coffee water that is too soft can also have a negative effect on the taste of the coffee. 

This can lead to a change in the swelling behaviour of the ground coffee. Over-extraction with high acidity and bitter intensity in the coffee and thus a low taste acceptance can be the consequences.

The pH value is also very important for assessing the water. The range of possible pH values ​​ranges from pH 0 (extremely acidic, e.g. hydrochloric acid) to pH 14 (extremely basic, e.g. sodium hydroxide solution). In the middle of the pH scale is the so-called neutral point with a pH value of 7. I

deally, the pH value of drinking water should be close to pH 7, but slight deviations are common and are completely harmless to health. The Drinking Water Ordinance stipulates that drinking water must have a pH value between 6.5 and 9.5.

The ideal value for coffee preparation is 7 – 7.2. For comparison:

Coca-Cola has a pH value of around 2.3, lemon juice around 2.5; so both are very pissed off. If the water is acidic (pH <7), the contact time does not play such an important role. Overall, coffee acids are emphasized more strongly and become more apparent. 

Coffee shows “what’s in it” much more clearly than with hard water with a high carbonate hardness and high (= alkaline) pH value. 

You can easily find out the hardness levels and all other relevant values ​​of your drinking water from your regional water supplier (mostly from the municipal utilities). 

You can find out which water supply company is responsible for you on your water bill. However, please state your exact place of residence, because many water suppliers obtain water from different origins, so that the water of a supply area unless it is mixed water, can be different depending on the place of residence or city district. With some water suppliers, it is even possible to inquire about the values ​​for individual streets and house numbers.

What many lovers of espresso, cappuccino & Co. do not know: the use of water filters can significantly improve the taste of the coffee. Because filtered tap water is softer. When preparing coffee, it ensures better aroma development and more taste. Also pure or chilled – as an extra with coffee – filtered water tastes great. 

Another advantage: Filtered water effectively protects espresso machines and fully automatic coffee machines from calcification. 

A positive effect for the devices: a longer service life and lower energy consumption.

The consequences of using water that is too mineral-rich:

Flavor Block 768X335 1

Graphic: BWT water + more

Too much calcium in the water is blocking the flavour.
»Flavour does not dock on the receptor on the tongue
» No signal to the taste centre
»Coffee tastes bland!


Flavor Blocking 768X343 2

Graphic: BWT water + more

Flavour is blocked by too much calcium in the water.
»Aroma does not dock to the receptor in the nose
» No signal to the olfactory centre
»Coffee has no aroma!

Controlling the minerals in the water is important for both taste and aroma.

You can always find some great BWT filters on Amazon.

I really think it`s of huge importance, to use good water, as it`s the effect on your coffee is immense.

After I started using a water filter, I have re-discovered my love for coffee, but funny enough also for drinking water.


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