How much does water quality affect the taste of your coffee?

Do you live in an area with hard water or soft water?

Do you know what other substances are in your tap water?

The Impact of Water Hardness on Coffee Taste

For coffee connoisseurs, these are important questions because they may affect the taste of your coffee.

Areas with notably softer water will most probably enjoy a slightly lighter tasting coffee, whilst those in hard water areas may find their coffee stronger and punchier. This is mainly because the flavour compounds in coffee cling to the minerals in the water.

Water Composition and Its Effect on Coffee Brewing

According to researchers, “Coffee brewed with tap water often lacks clarity and balance, whilst also leading to limescale in our kettles and other brewing equipment, especially in London, where the water is particularly hard.”

In addition, there may be minerals and other substances dissolved in tap water. Distilled water is the only kind that contains no minerals. In general, the more minerals are in your tap water, the harder it is.

Understanding Minerals and Water Hardness in Coffee Brewing

The most important minerals in drinking water are calcium, magnesium, sodium, and potassium, as well as chloride, sulphate, and hydrogen carbonate. These are measured as TDS (Total dissolved solids).

Of these, the carbonate hardness is the same as alkalinity. Hydrogen carbonate neutralises acids which can affect the taste of coffee since Caffeic acids are a crucial factor in the taste of coffee.

If there is a lot of hydrogen carbonate or the water is too hard, it reacts with the fine caffeic acids. The coffee then tastes unbalanced, bitter and flat.
Chlorine added to tap water as a disinfectant can also affect coffee flavour. It can give water an unpleasant odour and unpalatable taste.

Specialty Coffee Association Standards and Simple Solutions for Better Coffee

The Speciality Coffee Association sets a standard of 75-250 Mg per Litre of TDS in water used fot making coffee.

You can test your tap water to find out its contents, but if all this is too much, there’s a simple rule – just use bottled or filtered water to brew coffee.