A couple extra notes before we start: Avoid any coffeemaker that continues to apply heat to the coffee after it’s brewed. After more than 15 minutes’ exposure to direct heat, your coffee changes chemical structure. All kinds of bitter, acrid compounds emerge that not only taste terrible, but also treat your stomach lining like Freddy Kruger in a bouncy castle. Finally, never reheat or microwave your coffee. Nothing — and we mean, nothing — good can come of that.
Now, here are the brewing basics:
Use clean, fresh water.
Because coffee is 98% water, it’s important to have the best water possible when preparing it. Clean, fresh water is also essential to proper extraction. Filtering the water reduces impurities. In areas where the water is extremely hard, or when old plumbing gives it an “unpleasant” flavor, bottled water is recommended.
Water should always be freshly drawn and never re-boiled. Never use hot water directly from the tap or water that’s been boiled for a long time. Water that’s been re-boiled has been deoxygenated, resulting in a cup that’s flat, lacking clarity and acidity.
In the Groundwork stores, a water formulator is used to get the proper amount of total dissolved solids for brewing coffee. This water formulator utilizes the local water to filter out the impurities and impart the proper amount of dissolved materials: such as magnesium, calcium, sodium, and sulfides for proper extraction.
Use the correct water temperature.
For brewing coffee, the proper water temperature is between 195-205°F. If the water is too hot it will scald the coffee; the results will be bitter and over-extracted, with burnt and sometimes rubbery notes in the cup. If the water is not hot enough, the result will be under-extracted, displaying sour, bitter flavors and a thin, watery consistency in the cup. At home, proper temperature can be achieved by letting the water rest for a moment after coming to boil. When in doubt, use a thermometer.
When using a pour-over or other manual brewing method, it’s best to use water that’s on the hotter side, keeping the coffee slurry at about 200°F. It’s also important to remember to preheat the brewing equipment to ensure proper heat retention during the brew cycle.
Measure your coffee and water every time.
One way to ensure consistent brewing results is to measure your coffee and water. The water-to-coffee ratio should be between 15:1 and 18:1 depending on desired brew strength. Translation: roughly 2 tablespoons per 6 oz. of water.
The best way to ensure that you’re measuring correctly, and that you have the proper dose, is to use a scale when brewing.
Start with fresh roasted whole bean coffee.
Once it’s been roasted, coffee is sensitive to light, heat, air, and moisture. It’s best to keep coffee in whole-bean form in an air-tight, light-fast container to ensure freshness until brewing. Grind only the amount of coffee that’s needed for the brew-cycle and make sure to have the proper grind setting for the method of brewing. If the coffee is ground too fine, the results will be bitter and over-extracted. If the coffee is ground too coarse, the results will be watery and under-extracted.
The amount of time that coffee grounds are in contact with water, as well as the amount of agitation given to the coffee/water slurry, are important factors in brewing. Knowing the correct grind, proportions, and water temperature is key to any coffee recipe. Manual brewing methods require focus on duel time, the flow rate of the water, and the amount of agitation (or stirring) during the brewing process. The key here is to select a recipe and be consistent. For example, try to finish pouring the water for a manual drip in a given amount of time. Or keep track of the contact time and brew cycle when using a press-pot. Try stirring the coffee and water the same way during the brewing process. Also, use the same amount of water each time for pre-infusion.
Only brew what you plan to drink.
There are many volatile aromatics and flavor compounds found in brewed coffee that will dissipate over an extended period of time. For best results, coffee should be consumed within 20 minutes of brewing.
Now that science class it out, get to brewing!