Nav: Home > Coffee >

What Water Makes Better Tasting Coffee?

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, A drip coffee is over 98% water, and what water you use to brew coffee directly affects the final flavor expression. Therefore, water is a fundamental and important component of pour-over coffee, with its ranking status being second only to the coffee beans themselves. In daily life, water choices are diverse, but what kind of water is suitable for brewing

With over 98% of drip coffee consisting of water, the type of water used for brewing directly impacts the final flavor profile. Therefore, water is a fundamental and crucial component of pour-over coffee, ranking second only to the coffee beans themselves in importance.

In daily life, there are numerous water choices available. So what kind of water is suitable for brewing coffee? Let FrontStreet Coffee guide you through today's exploration of "water" in coffee brewing.

What Requirements Should Coffee Brewing Water Meet?

During the coffee brewing process, water acts as a solvent, responsible for extracting various flavor compounds from the coffee. Generally, coffee brewing has two main requirements for water: hardness and pH level. (ppm requires a specialized TDS reader, while pH values can typically be measured with instruments or pH test strips.)

Let's first discuss water's pH level. As we likely learned in school, a pH value of 7 represents neutrality, with smaller numbers indicating higher acidity and larger numbers indicating higher alkalinity. Coffee generally has a pH between 5-6, making it mildly acidic. When using weakly alkaline water to brew coffee, it neutralizes some of the coffee's acidity, reducing sourness and thereby balancing the overall taste. Currently, the industry consensus is that coffee brewing water ideally has a pH between 6.5-7.

Understanding Water Hardness

Water may appear colorless and tasteless, but even pure "clean water" isn't completely devoid of content. For instance, "transparent" seawater contains large amounts of ions such as sodium, potassium, calcium, magnesium, and strontium, which is why we can easily perceive water's "impurities." In the water we encounter daily, these minerals exist in trace amounts—barely noticeable yet directly affecting water hardness.

According to the World Health Organization's "Guidelines for Drinking-Water Quality," water with hardness below 200ppm is considered soft water, while anything above 200ppm is classified as hard water. Generally, hard water is not suitable for brewing coffee as it can make the taste unpleasantly bitter. For coffee brewing water, the SCA (Specialty Coffee Association) recommends a range of 75-250 ppm, with an ideal value of 150ppm.

Water is composed of countless elements, with magnesium, calcium, and bicarbonate being most crucial for coffee extraction. The hard water mentioned earlier essentially refers to excessive magnesium and calcium content. Water containing appropriate amounts of calcium ions can better dissolve coffee's acidity, while water with suitable magnesium ion content can effectively enhance the release of coffee's sweetness and aroma. Therefore, to brew delicious coffee, water must contain appropriate amounts of both calcium and magnesium ions.

Can Tap Water Be Used for Coffee Brewing?

Based on the water requirements mentioned above, we can first rule out tap water. Taking Guangzhou region where FrontStreet Coffee is located as an example, although tap water with a hardness of 150-180ppm falls within the soft water category, it still contains trace amounts of chlorine. Experienced coffee enthusiasts likely know that kettles used for boiling tap water quickly develop white scale on their inner walls, and the brewed coffee's aroma will be diminished, with noticeably uncomfortable bitterness and astringency.

Therefore, many households install filtration systems to obtain higher quality drinking water. To determine if hardness has been reduced, we need to use a "magic tool"—a TDS reader—and attempt brewing to compare flavors and see if extraction has improved.

At this point, some might ask: This seems so troublesome—are there any ready-to-use bottled/barreled waters suitable for coffee brewing? Of course! This is when mineral content and pH value become the key factors we need to focus on.

Purified Water, Spring Water, or Mineral Water: Which Brews Better Coffee?

To explore this question, FrontStreet Coffee first used the spring water from their daily operations as a baseline and made a "significant investment" in purchasing purified water and mineral water. Using the same parameters, they brewed one pot of bitter-profile coffee and one pot of acidic-profile coffee to test the effects.

From information provided on the drinking water packaging, FrontStreet Coffee used purified water with a pH of 7.1±0.5 and TDS of 0ppm; spring water with a pH of 7.3±0.5 and TDS of 37ppm—both neutral waters; while mineral water had a pH value of

Coffee beans: 15g Jamaica Blue Mountain No. 1 & Kenya AA
Coffee-to-water ratio: 1:15
Corresponding water temperatures: 88°C & 91°C
Corresponding grind settings: EK43s setting 10.5 & 10 (0.85mm sieve pass rates of 75% and 80%)
Three-stage extraction: 30g, 95g, 100g
Extraction time: 2 minutes to 2 minutes 10 seconds

Purified Water Performance:

Blue Mountain primarily displayed hazelnut flavors with an overall round and sweet taste, though not bitter, but with weak aroma and body. Kenya showed distinct plum and black plum-like acidity with a hint of snow pear sweetness, but the acidity felt somewhat hollow, and the aroma was mediocre.

Spring Water Performance:

Blue Mountain first presented an inviting aroma of chocolate and nuts, with a smooth mouthfeel, leaving behind caramel and brown sugar-like notes after swallowing—showing the richest layers and most persistent body. Kenya displayed clear dark plum flavors with prominent juiciness, accompanied by floral notes and a clean finish.

Mineral Water Performance:

Blue Mountain failed to exhibit its characteristic body, with bitterness dominating. At lower temperatures, unpleasant acidity emerged, mixed with a powdery texture, suggesting over-extraction. Kenya also performed poorly, with an unpleasant strong acidity and dull tea-like notes—flavors were present but very muddled.

Based on FrontStreet Coffee's small experiment conclusion, compared to 0ppm purified water and weakly alkaline mineral water, coffee brewed with 37ppm neutral spring water demonstrated more stable performance in both compatibility and flavor. That's right—it's Nongfu Spring Water. Of course, there are many other drinking water products on the market, which paired with different coffee beans and parameters might present unique flavor layers. Everyone might want to experiment with comparisons like FrontStreet Coffee did—you might discover new territory!