Coffee is mostly water, so the water you choose has a direct effect on how your cup tastes. The National Coffee Association’s brewing guides for drip, cold brew and pour-over all stress that water quality is one of the three consistent elements of great coffee, alongside choosing the right beans and grinding them properly.
Why water quality matters for coffee
Brewed coffee is mostly water, so off flavors in your water end up in the drink. The National Coffee Association’s guides for drip coffee, cold brew and pour-over each include the same core advice: use cold water, filtered if possible, and avoid distilled or softened water. This recommendation appears in all three brewing method pages, showing that water selection is a universal step no matter how you brew.
What the National Coffee Association says about water
According to the National Coffee Association’s drip coffee guide, you should “use cold water, filtered if possible, and avoid distilled or softened water.” The same wording appears in the cold brew guide, which says “use filtered water, if possible, and avoid distilled or softened water.” The pour-over guide repeats the instruction: “use cold water, filtered if possible, and avoid distilled or softened water.” The association does not go into detail about why distilled and softened water are discouraged, but the consistent advice across methods makes it clear that filtered tap water is the preferred starting point for home brewing.
If your tap water tastes fine on its own, it will likely produce acceptable coffee. However, if your water has a noticeable chlorine taste or high mineral content, a simple water filter pitcher can help. The drip coffee guide also says that if your coffee maker has an external water filter, you should follow the manufacturer’s instructions for cleaning or replacing that filter as needed.
Water temperature by brewing method
Different brewing methods call for different water temperatures, and some methods have published numbers while others are left to the machine’s design.
Pour-over coffee
The National Coffee Association’s pour-over guide cites the Specialty Coffee Association’s standard for water temperature. It states that “the SCA Standard 102-2024 Coffee Value Assessment: Sample Preparation and Tasting Mechanics suggests that the optimal water temperature before pouring over coffee grounds is 93 ± 3°C.” This range, roughly 195°F to 205°F, is the target for manual pour-over brewing. The guide also suggests that if you boil water on the stove, you should let it come to a full boil, turn off the heat immediately, and then let the water rest for about a minute to bring it down to the optimal temperature. A gooseneck kettle with a built-in thermometer makes it easier to hit and hold that temperature.
AeroPress
The AeroPress instructions on the manufacturer’s website give a specific water temperature: “Heat water to 185°F (85°C) using your kettle. If you don’t have a temperature control kettle, use boiling water.” This lower temperature is part of the AeroPress recipe, and the instructions note that using boiling water is an acceptable alternative if you lack a temperature-controlled kettle. The AeroPress guide also provides dose and timing details, but the water temperature is the key water-related number.
Drip coffee
The National Coffee Association’s drip coffee guide does not list a brewing temperature. It simply says to use cold, filtered water. Automatic drip machines heat the water internally, so the temperature is determined by the coffee maker’s design. The association’s advice is to follow the instructions that come with your machine. If you are shopping for a drip coffee maker, the guide suggests looking at features such as programmability, safety measures like automatic shut-off, and customer reviews, but it does not specify a temperature range for the brew cycle.
Cold brew
Cold brew, by definition, uses water at room temperature or cooler. The National Coffee Association’s cold brew guide states that the brewing temperature is “room temperature or cooler, then served immediately or chilled in the refrigerator.” There is no heating step, so the water temperature is whatever comes out of your tap or filter pitcher. The guide recommends filtered water and a steeping time of approximately 12 hours.
Accessories that help with water
You do not need a lot of gear to manage water for coffee, but a few simple accessories can make the process more consistent. The National Coffee Association’s pour-over guide recommends a kettle with a long, thin gooseneck spout, which helps control the flow of water and preserve the water temperature. It also suggests having a thermometer on hand if your kettle does not have one built in. A basic water filter pitcher can improve tap water that has off tastes, and some drip coffee makers have an external water filter. The association’s drip coffee guide reminds users to check the manufacturer’s instructions for cleaning or replacing that filter. For a broader look at the tools available, see our water and accessories page.
Cleaning your coffee maker’s water reservoir
Over time, minerals from tap water can build up inside a coffee maker, especially if you use unfiltered water. The National Coffee Association’s drip coffee guide explains that this mineral buildup is called scale, and the process to remove it is descaling. The guide says that “major manufacturers recommend descaling your coffee maker at least every 3-6 months.” It notes that descaling methods vary by machine, so you should check your coffee maker’s instructions. Some machines can be descaled with a solution of white vinegar and water, while others require a specialized descaling solution. After descaling, the guide advises running several cycles of plain water to rinse away any lingering taste. The same principle applies to any coffee equipment that holds water, from drip machines to espresso machines: follow the manufacturer’s cleaning schedule to keep your brewer working well and your coffee tasting fresh.
Frequently asked questions
What kind of water should I use for coffee?
The National Coffee Association’s guides for drip, cold brew and pour-over all recommend using cold water, filtered if possible, and avoiding distilled or softened water. Filtered tap water is the simplest choice for most home brewers.
What temperature should I use for pour-over coffee?
The National Coffee Association’s pour-over guide cites the SCA standard of 93 ± 3°C (roughly 195°F to 205°F) as the optimal water temperature before pouring over the grounds. If you boil water on the stove, let it rest for about a minute to reach that range.
How often should I descale my coffee maker?
The National Coffee Association’s drip coffee guide states that major manufacturers recommend descaling at least every 3-6 months. Check your machine’s manual for the correct descaling method, and always rinse thoroughly afterward.
For more on water filters, kettles and other accessories that help you control water quality and temperature, visit our water and accessories category. You can also explore the full coffee equipment section or read our home coffee equipment guide to see how water tools fit into a complete setup.
