Today, we’ll be taking a look at what are considered the 5 most important factors when it comes to brewing the best drip coffee. The most important thing to remember when brewing any type of coffee is that you’ll have to experiment to find exactly what you’re looking for. You may have to brew three of four different test batches to really dial in your machine. Luckily, a few groups like the Specialty Coffee Association of America (SCAA) and America’s Test Kitchen have done a lot of testing on these different variables with many different brewers and their results will help you hit the ground running!
First and foremost, you’ll want to select a high quality coffee to brew in your drip machine. It is important to purchase your coffee as soon after it has been roasted as possible. Fresh roasted coffee is extremely essential to a great cup of drip brewed coffee. You should only purchase specialty coffee in small amounts – generally only as much as you’ll use in a given period of time, say 1 to 2 weeks. After you’ve selected the type of coffee that you’ll be brewing, keep these important factors in mind during the brew:We’ll start off with the water that you use to make your coffee. Water constitutes a large portion of the finished product when you drip brew coffee, so using the highest quality water available to you is paramount to making an excellent brew. Generally, using filtered water or bottled water will give you the best water quality for drip brewed coffee, but feel free to experiment; you may find that you enjoy the taste of your tap water over bottled or filtered water! The SCAA recommends certain standards for the water used to brew specialty coffee, just in case you want to know what the absolute best is when it comes to water:
1. Water Quality
- Odor – The water should have a clean and fresh scent without any chemical odors or other unusual smells.
- Color – The water should have a crystal clear color and should not be cloudy.
- Total Chlorine Content – 0 mg/L
- Total Dissolved Solids (TDS) Content – 150 mg/L (target), 75-250 mg/L (acceptable range)
- Calcium Hardness – 68 mg/L (target), 17-85 mg/L (acceptable range)
- Total Alkalinity – 40 mg/L (target), at or near 40 mg/L (acceptable range)
- pH Level – 7.0 (target), 6.5 to 7.5 (acceptable range)
- Sodium Content – 10 mg/L (target), at or near 10 mg/L (acceptable range)
2. Water TemperatureThis is where a high quality machine comes into play. Your brewer should be able to maintain a water temperature between 195° F to 205° F for optimal coffee extraction. When you use water that is lower than 195° F it will result in an under-extracted extremely flat and watery tasting coffee; when you use water that is higher than 205° F it will cause the finished product to become acrid and bitter and will cause a noticeable loss of quality in the taste of the coffee. The sweet spot is generally right around 200° F although you will have to tinker within the acceptable range to find what you enjoy the most.
3. Ratio of Water to Coffee Grounds
This is the hallowed battleground for coffee nerds world round (seriously, Google search for “coffee to water ratio” and select images). There are many differing opinions as to what the most correct coffee to water ratio is. This never ending argument is for a good reason though as your decision here will have the greatest impact on the quality and taste of the finished coffee. A good rule of thumb: ABOUT 2 TABLESPOONS OF COFFEE FOR EVERY 6 OUNCES OF WATER (1 GRAM OF COFFEE FOR EVERY 16 MILILITERS OF WATER). Again, this is something that you will have to adjust a few times before you get it exactly right.
4. Size of the Grind
Along with the timing of the brew cycle, this component of the process will have a noticeable impact on the taste of your finished coffee. If you prefer to purchase coffee in whole bean form you should always take care to grind your beans as close as possible to the start of your brew in order to maintain the integrity of the coffee and keep it as fresh as possible.
Consistency is the key! A burr or mill grinder is the preferred method for grinding as the ground coffee will be consistent each time. Blade grinders will have less consistency and may affect the quality and consistency of your grind. If your coffee tastes bitter it is probably over-extracted, or ground too fine. If it’s flat or watery it is probably under-extracted, or ground too coarsely. Many times, expert roasters have determined for each of their roasts exactly what the best grind size is for different types of coffee preparation and will grind it to that size for you upon picking up your beans, just ask! You’ll have to play around with the grind size to find what suits you best, but a medium grind is generally considered optimal for drip brewing.
Also, this should go without saying but NEVER EVER reuse your spent coffee grounds, all of the good stuff has been extracted and you’ll only get bitter after tastes when you reuse extracted coffee, it’s not worth it!
(Baratza is considered to be one of the best in-home grinder available on the market)
5. Brew Cycle Timing
This component of brewing will have a major impact on the flavor of your coffee. The brewing time is the amount of time that the heated water is in physical contact with the ground beans. The length of time that the brewing process is allowed to go on for will have a direct effect on the quality of your finished coffee. Water contact time should be determined primarily by the size of the grind that you use and the depth of the ground coffee (known as the “coffee bed”). Recommended brew cycle times range from 1-4 minutes for finely ground coffee, 4-6 minutes for a medium-fine (or Drip) grind, and 6-8 minutes for a coarse grind. The general guideline is the finer the grind, the shorter the time.
There are three major components to the brew cycle:
- Pre-Wetting (or Wetting) – As the brew cycle begins, the ground coffee starts to absorb the water as it is released from the machine. The coffee begins to release gases as it brews. For a consistent extraction, the entire bed of coffee must be evenly pre-wetted within the first 10% of the brewing cycle time.
- Extraction – After the grounds release their gases and are thoroughly wet the actual process of extraction begins. During this phase, the water-soluble materials dissolve and move out of the coffee grounds and into the water. The best and most desirable flavors are extracted near the beginning of the cycle and the most bitter are extracted near the end of the cycle.
- Hydrolysis –Through chemical reaction with the water, the materials that were created during the extraction process are broken down further into water soluble proteins and sugars that truly define the taste of a cup of coffee.
Making truly great drip coffee can be a simple task if you have practiced a little and set the parameters of your machine to work with the water and coffee that you are using. Also, good equipment doesn’t hurt either. One of the most important factors when making drip coffee is the coffee brewing machine itself. A subpar machine will leave much to be desired as far as water temperature and cycle time consistency. Thankfully, America’s Test Kitchen set out to find exactly what drip brewer makes the best coffee: