Writer Kim Jin-ho's Water and Health Story (63) Water and Coffee, Overlooked Amid the Obvious

Café Competitiveness Begins With Water

In our daily lives, we take clean water for granted. Most households are equipped with 3 to 4-stage water purification systems, and those with children or pets are even more sensitive to water quality. Drinking purified, clean water has become not a 'choice' but a 'necessity'.

But what about coffee? Coffee, which has become the norm to consume one or two cups a day, is now more than just a beverage—it is an important presence that adds comfort and rhythm to our daily lives. Yet despite knowing that 98% of coffee is 'water', many do not apply this fact to actual café management or quality control.

The Most Important Ingredient Cafés Are Overlooking

Many cafés carefully select high-quality beans, invest in expensive espresso machines, and put effort into coffee taste. Baristas meticulously adjust roasting, extraction temperature, and grinding fineness. However, interest in 'water'—the very starting point of all these efforts—is surprisingly minimal.

In reality, most cafés use only a single carbon filter to purify their water. Water enters the espresso machine and customers' cups with only basic filtration—removing chlorine or reducing its levels without eliminating contaminants from water pipes. This is merely 'primary filtration'.

The results manifest clearly. The beans are good, but the coffee tastes bland, flat, too acidic, or too bitter. Is it the machine's fault? The beans' fault? No. When the water itself is of poor quality, even the finest beans and machines cannot properly extract their flavors.

Coffee Flavor Begins With Water

Good water is not simply water free of impurities. It must be water with properties suitable for coffee.

First, consider mineral content. Magnesium, in particular, plays a crucial role in bringing out coffee's sweetness and achieving a nutty flavor with balance. When minerals are insufficient, coffee's sweetness becomes muddled, leaving a bland or flat taste.

pH (hydrogen ion concentration) is also important. Alkaline water gently regulates coffee's acidity and reduces excessive bitterness. Additionally, water particle size affects extraction efficiency and mouthfeel. The more finely the water is purified, the more evenly the bean components are extracted, and the more the smooth texture is enhanced.

Ultimately, coffee is a beverage completed through the harmony of beans, water, and temperature. If any one of these is lacking, the quality of coffee taste that customers experience inevitably suffers.

Sustainable Café Management Determined by 'Water'

Now, water has become an indispensable element when discussing the quality of a cup of coffee. The issue is that this is not limited to 'taste' alone.

Today's customers are far more sensitive than before. Beyond mere taste, they consider the source and quality of ingredients, hygiene, and sustainability. In this era, 'water' is no longer merely a raw material—it can become a symbolic element demonstrating the attitude with which a café treats customers and coffee.

Moreover, when coffee taste is consistently maintained, customer return visits increase and bean consumption can be reduced. Ultimately, improving water quality leads not only to enhanced customer satisfaction but also to securing sustainable competitive advantage that maintains café sales and profitability in the long term.

Leading specialty coffee shops and large café chains are already adopting mineral-maker purification filter systems optimized for coffee extraction. This should not be seen as mere equipment investment but as a café's philosophy and competitive strategy.

Now, Cafés Must Check Their Water

There are actual testimonials from café owners reporting that coffee taste changed simply by switching a purification system. Customers experience the difference firsthand—fresh sweetness, smooth texture, clean finish—and return their empty cups without a word.

Water represents a small portion of coffee production costs but has significant impact on taste and brand image. And this extends to customer loyalty, repeat visits, and brand reputation.

The era of sidelining water when discussing coffee quality has passed. The beginning of coffee is ultimately water. We must always remember that the moving cup of coffee we wish to deliver to customers also begins with water.