What determines the quality of coffee?

Planting, picking, processing, exporting, roasting, grinding, brewing, these are the key links from coffee production to production. But when it comes to quality, we often forget the importance of water.

In fact, water is also one of the key factors affecting the quality of coffee. No matter how good the coffee beans and coffee machines we use, without good water, we will not be able to make good coffee. We must pay attention to water because water accounts for 92% of espresso and 98% of drip coffee.

Water can bring out the acidity or completely erase it; it can extract a lot of fruity and floral flavors, or it can make the coffee bland. How does water affect the quality of coffee? Water contains a large number of positive and negative minerals. What we need to do is to find the balance point so that all elements can be combined accurately.

Total hardness (GH)

Simply put, it is the content of calcium and magnesium. Both substances are important because they can help extract the flavor of coffee. Calcium can increase the taste, and magnesium can extract acidic molecules, making coffee sweeter and citrus acid stronger. But at the same time, calcium can also produce scale because it cannot dissolve in water.

Bicarbonate hardness (KH)

Bicarbonate hardness or temporary hardness acts as a buffer. Carbonates and bicarbonates keep the pH of the water stable (6.5-8 according to the SCA standard). A stable pH is important for a balanced flavor. Too little carbonate hardness can create a lazy, sour taste, while too much carbonate hardness can weaken the acidity and make the coffee taste flat.

pH

The pH value is used to measure the acidity or alkalinity of water, and the value ranges from 0-14, with 7 being neutral. A low pH value indicates that the water is acidic, while a high pH value indicates that the water is alkaline.

For example, the water quality in London is usually hard, which will cause scale to grow inside the coffee machine, reduce the stability of heating, slow down the water flow, and damage the internal parts. For this reason, we need to use a water filtration or water softening system to adjust the water quality.

Reverse Osmosis Filtration

This is the most expensive water treatment system and is usually used in coffee shops with high customer traffic. After being treated by this equipment, the water will become distilled water without any minerals or other chlorine or sulfate. But at this stage, we can't use it directly to brew coffee, because using distilled water will make the coffee tasteless. Only after filtering and adding the right amount of minerals can it be used to brew coffee.

Carbon Filtration

Carbon filtration has a lower interval, but it can only remove odors and cannot change the mineral content.

Soft water system

A water softener is suitable for home use and works by filtering water through a resin, which is used to exchange ions. The resin reduces the hardness of the water and removes the minerals, sodium and potassium. The resin must be changed regularly, with sodium hydroxide or sodium chloride added when it is saturated. I also recommend adding a carbon filter to remove odors.

In general, there is no perfect water in the natural environment. You need to balance the content of various minerals to continuously improve the quality of water.

author

Edoardo

English original address

https://coffeextraction.com/coffee-basics/the-impact-of-water-on-coffee-taste/