To make the best cup of coffee you need the ingredients to be the best quality, and yes, this includes the water you use! Water contributes up to 94-98% of a coffee beverage make up. This causes it to palpably affect the flavor and smell. Therefore, just like equipment and storage, it is important to understand how it can affect your cup of joe.
Water, being a solvent, dissolves minerals from the environment, and in turn affect the taste of your coffee. One example is hydrogen carbonate, a mineral found naturally in water. When there is too much of this component around it can have a chemical effect. It will neutralize caffeic acids causing coffee to lose flavor. Also, using “hard” water that contains too much calcium and magnesium causes coffee to be unbalanced, flat, and bitter. It is recommended to use “soft” water with lower levels of these minerals because it does not greatly affect the cup of coffee.
Substances added to treat water, like chlorine used to disinfect tap water, can give it an unpleasant odor and taste. Chlorine, even if not detectable by taste, can cause reactions that ruin the coffee aroma profile. Here are some examples given in an article by the Specialty Coffee Association:
- Chlorine: Sweet like chlorine
- 2-Chlorophenol: Medical
- 2,4,6- Trichloro anisole: Cork-like, musty
- Mono- Chloramine: Pungent, like a swimming pool
Water temperature is also a key factor. If it is not hot enough, you may not get the full flavor of your coffee. However if it is too hot, it can also dull the flavor. The recommended temperature is 195-205 degrees. This makes 200 degrees your sweet spot for for the perfect extraction. Most of your average coffee machines will hit that range just right. However, when you are working with a pour over, it is recommended that you use a kettle with a temperature gauge to ensure optimal heat level.
Lastly, if you ask anyone the ratio of water and coffee can make or break the cup! Too much coffee, and the flavor could be overpowering; too little coffee, and it could be diluted. While it depends largely on your preference, a general rule is the best ratio is to use 17.4 units of water to 1 unit of coffee. For those that prefer a simple description, that is for every six ounces of water, you should have about two tablespoons of coffee.
In conclusion, from the natural minerals found, substances added, and the very amount used, the water used can affect your coffee to the point of being undesirable or the best Cup of Joe imaginable. So, next time you brew keep these facts in mind and choose wisely!