Coffee is 98% water, 2% everything else. Don't leave such a crucial ingredient to chance.
How can you consistently brew a great product? If your 98% raw ingredient is so full of the things that can work against making that perfect cup.
Chlorine, Bad Tastes, Odours, Sediment, Excessive Minerals and Lead just to name a few.
Impure Water will take what could be a great coffee and make it taste awful.
On the other hand the right kind of water can help bring out all of the incredible flavours, aromas and nuance that the Roasters intended.
Impure Water can damage your expensive coffee brewing equipment
Not only does water affect the taste of a cup of coffee, but it can significantly affect the brewing equipment itself. The challenge to a premium cup of coffee is to find a water filtration solution that creates the perfect balance between protecting an operation’s equipment investment and capturing the desired taste and aroma.
Here are some qualities of tap water and how they may affect the final product:
Total Dissolved Solids (TDS)
The TDS of the brewing water is a very important criteria indeed. TDS is a measure of salts dissolved into the water and is not specific to the type of salt. As the salt level of water increases, its ability to absorb other constituents decreases. That is to say if the TDS in your source water was quite a bit higher than the Roasters source water, you might not get as many constituents extracted from the bean and this will result in a weaker brew. If the constituents in your water were such that they impart their own flavours such as trace metals and chlorine, this would also alter the flavour of the brew. Conversely if the water is too pure or empty if you will, too much may be extracted from the grind, and the flavour spoiled.
pH can radically affect the solubility of organic components in water. At lower pH (below 7.0) organics in water generally become less soluble. This would cause the brews aromatic quality to increase and in doing so shorten the lifespan of the pot. A heavy up-front aroma might not be what the master intended. Conversely as pH rises, more organics can be absorbed into the brew causing less aroma and more bitterness in the after-taste.
Calcium & Magnesium
Calcium and magnesium are commonly found dissolved in water with calcium being the more abundant but also one of the main causes of limescale issues. Both calcium and magnesium have been claimed to be better at extracting coffee flavour. While the levels needed for that perfect brew may be quite subjective it's generally agreed that some minerals are necessary to enhance flavours and that too much will detract from the final product
Sodium & Potassium
Sodium is usually found in tap water in higher levels than potassium. At low levels these minerals can add sweetness to a coffee’s flavour, though sodium is a component of salt, so obviously too much will be detrimental. Salty coffee… yummy!
Chlorides have a detrimental effect on stainless steel and at high levels can actually break down the protective coating causing pitting and corrosion.
Thinking of Water as an Ingredient,
Water is so ubiquitous in all we consume that it is hard to believe its qualities can affect how other components in our food react with one another. One might be even lulled into the idea that the more pure the water is, the better a beverage it will produce. This is in fact not necessarily the case.
Coffee brewing starts at the hands of a highly skilled Roaster. The Roaster must determine how to construct and formulate their coffee creation from a raw coffee bean to the finished product. This is no small feat.
After the bean has been roasted and possibly blended with other beans and flavours, the Roaster must determine how to develop their intention at every site their coffee is brewed. Remember that when the batch was developed, a particular water was used in getting the recipe just right. If the water later used to brew their coffee varies too greatly, the intended flavour will not be duplicated.