Here are our tips to brew a classic cup of coffee
Make sure that your tools — from grinders and filters to coffee makers — are thoroughly cleaned after each use.
Rinse with clear, hot water (or wipe down thoroughly), and dry with an absorbent towel. It’s important to check that no grounds have been left to collect and that there’s no build-up of coffee oil (caffeol), which can make future cups of coffee taste bitter and rancid.
Great coffee starts with great beans.
The quality and flavor of your coffee is not only determined by your favorite brewing process, but also by the type of coffee you select. There can be a world of difference between roasts.
Purchase coffee as soon as possible after it’s roasted. Fresh-roasted coffee is essential to a quality cup, so buy your coffee in small amounts (ideally every one to two weeks). And please, never reuse your coffee grounds to make coffee. Once brewed, the desirable coffee flavors have been extracted and only the bitter ones are left. If you buy whole bean coffee, always grind your beans as close to the brew time as possible for maximum freshness. A burr or mill grinder is best because the coffee is ground to a consistent size. A blade grinder is less preferable because some coffee will be ground more finely than the rest. If you normally grind your coffee at home with a blade grinder, try having it ground at the store with a burr grinder. You’ll be surprised at the difference!
The size of the grind is hugely important to the taste of your coffee. If your coffee tastes bitter, it may be over-extracted, or ground too fine. On the other hand, if your coffee tastes flat, it may be under-extracted, meaning your grind is too coarse.
The water you use is very important to the quality of your coffee. Use filtered or bottled water if your tap water is not good or has a strong odor or taste, such as chlorine. If you’re using tap water, let it run a few seconds before filling your coffee pot, and be sure to use cold water. Avoid distilled or softened water.
A general guideline is called the "Golden Ratio" - one to two tablespoons of ground coffee for every six ounces of water. This can be adjusted to suit individual taste preferences.
Check the cup lines or indicators on your specific brewer to see how they actually measure. And remember that some water is lost to evaporation in certain brewing methods.
Your brewer should maintain a water temperature between 195 to 205 degrees Fahrenheit for optimal extraction. Colder water will result in flat, under-extracted coffee, while water that is too hot will also cause a loss of quality in the taste of the coffee. (However, cold brew does not need any heat.) If you are brewing the coffee manually, let the water come to a full boil, but do not over boil. Turn off the heat source and allow the water to rest a minute before pouring it over the grounds.
Always allow your coffee - or any hot beverage - to reach a comfortable temperature before enjoying (specifically below 140 degrees Fahrenheit).
The amount of time that the water is in contact with the coffee grounds is another important flavor factor.
In a drip system, the contact time should be approximately 5 minutes. If you are making your coffee using a French Press, the contact time should be 2-4 minutes. Espresso has an especially brief brew time — the coffee is in contact with the water for only 20-30 seconds. Cold brew, on the other hand, should steep overnight (about 12 hours).
If you’re not happy with the taste of the final product, you're likely either:
Experiment with the contact time until you get the right balance for your taste.
From the National Coffee Association of USA Inc.