Understanding the 'Golden Ratio' for Brewing
Making great coffee is often considered an art, but at its heart, it relies on a consistent, scientific approach. The "Golden Ratio," recommended by the Specialty Coffee Association (SCAA), provides an excellent starting point: 1 part coffee to 18 parts water, or 10 grams of coffee for every 180 ml (6 fluid ounces) of water. Following this guideline ensures a balanced extraction and a rich, flavorful cup.
How many cups is 20g of coffee?
Applying the standard Golden Ratio, 20g of coffee grounds is the perfect amount to brew approximately 360 ml of water (around 12 fluid ounces), which translates to:
- Two standard coffee cups: Based on the SCAA's 6-ounce standard, 20g is just right for two 6-ounce cups.
- One larger mug: For those who prefer a single, larger serving, 20g will yield a delicious 12-ounce mug of coffee, a common size for home brewers.
Why Volume Measurements for Coffee Are Inaccurate
While it may be tempting to use a tablespoon or measuring cup, relying on volume to measure coffee is a recipe for inconsistency. The density of coffee can vary significantly depending on the roast, bean origin, and, most importantly, the grind size.
- Whole Beans vs. Ground: A tablespoon of whole beans weighs differently than a tablespoon of finely ground espresso. The air pockets in whole beans take up more space, meaning you'll get a lighter weight for the same volume.
- Light vs. Dark Roast: Darker roasted beans are less dense because the roasting process removes more moisture. Therefore, a tablespoon of dark roast will weigh less than a tablespoon of light roast.
- Grind Size: Coarsely ground coffee has larger air gaps between particles than a fine grind. This means that a volume-based measure, like a scoop, will contain less weight of coarse grounds than it would of fine grounds.
This is why coffee experts, such as the SCAE, strongly recommend using a digital coffee scale to ensure consistent results, cup after cup.
Adjusting Your Brew Strength
Not everyone prefers the standard Golden Ratio. If you like a stronger or milder cup, you can easily adjust the coffee-to-water ratio. The key is to maintain the proportions relative to your 20g of coffee.
- For a stronger brew (e.g., 1:15 ratio): Use 20g of coffee with 300g of water. This will produce a more concentrated, intense flavor.
- For a milder brew (e.g., 1:18 ratio): Stick closer to the Golden Ratio, using 20g of coffee with 360g of water, for a balanced and smoother taste.
A Simple Step-by-Step Brewing Guide for 20g of Coffee
- Start with the right tools: Invest in a digital scale for accurate measurements. This is the single most important step for brewing consistent coffee.
- Weigh your grounds: Measure exactly 20g of your favorite coffee beans or grounds. For optimal freshness, grind whole beans immediately before brewing.
- Heat your water: Bring your water to the ideal brewing temperature, typically between 195°F and 205°F (90°C–96°C). Avoid boiling water, as it can over-extract the coffee and result in a bitter taste.
- Brew your coffee: Follow the specific steps for your chosen method, whether it's a pour-over, French press, or automatic drip machine. Use your scale to measure the correct amount of water (e.g., 300g–360g for 20g of coffee).
- Enjoy: Once brewed, serve and enjoy your perfectly measured cup.
The Importance of Grind Size and Brew Time
Beyond the coffee-to-water ratio, two other factors dramatically influence the outcome of your brew: grind size and brew time. These elements are all interconnected and can be adjusted together to perfect your cup.
- Grind Size: The coarseness of your coffee grounds dictates how quickly water can extract flavor. A coarser grind requires a longer contact time, while a finer grind needs a shorter one.
- Brew Time: The duration water is in contact with the coffee grounds is crucial. If your brew tastes weak, you may need a finer grind or longer brew time. If it tastes bitter, you may be over-extracting by using too fine a grind or too long a brew time.
Comparison of Brewing Ratios and Cups for 20g of Coffee
| Ratio (Coffee:Water) | Water (g) | Water (oz) | Standard 6-oz Cups (approx.) | Brew Strength | Recommended For |
|---|---|---|---|---|---|
| Golden Ratio (1:18) | 360 | 12.7 | 2 | Balanced | Most drip coffee makers, pour-over |
| Stronger Brew (1:15) | 300 | 10.6 | 1.7 | Strong | Cold brew, espresso-style drinks |
| Mild Brew (1:20) | 400 | 14.1 | 2.3 | Mild | Delicate single-origin coffees |
Conclusion
While a definitive answer to "How many cups is 20g of coffee?" depends on your cup size and desired strength, the most consistent approach is to think in grams and ratios rather than cups. For two standard 6-ounce cups, 20g is an ideal starting point. Embracing a digital scale will eliminate the guesswork associated with volumetric measurements, allowing you to replicate your perfect cup of coffee consistently. Adjusting the ratio of coffee to water is a simple way to tailor your brew to your exact taste preferences, putting you in complete control of your coffee experience.
For more information on achieving the perfect extraction and understanding the science of brewing, you can explore resources from the Specialty Coffee Association (SCA).
