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If you’ve ever made a soup, you already know how important ratios and proportions are for taste. If you put too much broth or water in the pot, the soup might taste thin and watery. And if you put too little broth or water, the soup might taste too thick and heavy. It’s a delicate balancing act. But if you get it right, you’ll have the perfect proportion for a great-tasting bowl. The same principle applies to making coffee. Putting the right amount of coffee grounds and water into your machine can truly make or break your cup of coffee. These are the only two ingredients for making coffee. Which makes finding the right ratio between the two so essential.
Most folks already have a method for setting their coffee-to-water ratio. But there’s quite a bit of variance in comparing their accuracy. There’s the ‘eyeballing’ method, which is the least precise. Some use the ‘scoop’ method, measuring the amount of ground coffee by the number of scoops and filling the machine’s water reservoir with an amount of water to a pre-set line. But the most accurate method of measuring coffee and water is by using a scale, which takes out all the guesswork involved in determining the right amount of coffee and water for the machine.
Regardless of how you measure your coffee and water, you should always aim for a water-to-coffee ratio of 16:1. In other words, you should have 16 parts water for every 1 part coffee. This might seem like a lot of water and not so much coffee. But this is the ratio that the Specialty Coffee Association has determined to be the “golden ratio” for coffee brewing. Numerous studies have shown that this is the ideal ratio for nearly all human palates, regardless if you’re an experienced barista or a typical coffee drinker. And while this ratio varies slightly by brewing device, it is a good starting point for home enthusiasts, whether you make your coffee in an automatic drip coffee machine, a Chemex, a French press, or an AeroPress.
Measuring Coffee With A Scale
A scale is the best tool you can use to get the most precise and consistent cup of coffee possible. You should use it to determine both the amount of water and coffee you’ll want to use in brewing. First, decide how many cups of coffee you’d like to brew. In this example, let’s say we want to make six cups. A ‘cup’ of coffee is not a standard unit of measure, but most coffee machine manufacturers indicate that a cup is 6 ounces of liquid coffee. So making a 6-cup pot of coffee is equal to 36 ounces of liquid coffee.
Here, we’re going to convert our 36 ounces to milliliters. Most coffee professionals use the metric system when measuring coffee and water, for two main reasons: the math is simply easier in grams and milliliters. And outside of the United States, most countries use these units of measure in their daily lives.
Back to our pot of coffee. 36 liquid ounces is equal to about 1,020 milliliters of coffee, or just over one liter. (1 ounce is equivalent to approximately 28.35 milliliters). Now that we have our total amount of water, we can determine the amount of ground coffee to use in brewing. This is where our magic water-to-coffee ratio of 16:1 comes into play. Simply take the total weight of the water in milliliters and divide it by 16. In this example, our 1020 milliliters of water divided by 16 comes to roughly 64 grams (1 milliliter is equal to 1 gram). This is the amount of ground coffee you should use in brewing a six-cup pot of coffee.
To put it in even simpler terms, and to allow you to change the amount of coffee you want to brew, here are two equations to use to determine the amount of water and coffee you in brewing: Water (in ounces): (# of desired cups) x 6 / Coffee (in grams): ((# of desired cups) x 6 x 28.35)/16.
Measuring Coffee and Water by Volume
Since this method for measuring coffee and water uses utensils most people already own, I think beginners should start here. The National Coffee Association recommends 2 level tablespoons of ground coffee for every 6 ounces of water. This is a good starting point to get in the ballpark of where you should be. If you are using an automatic drip coffee pot, this is probably a good bit more coffee than you have been using. As I mentioned earlier, your coffee pot probably cannot handle this amount of coffee for a full pot.
If your coffee pot isn’t particularly high-end with a wide-dispersing shower head, I would recommend making about half a pot with this ratio. Also, be aware of how the lines on your carafe translate into ounces. Many drip pots use 5-ounce increments, so adjust accordingly. When measuring this way, you probably will find it easiest to start with a measuring cup rather than using lines on a carafe. While this method of measuring coffee to water is easy to start with, it is imprecise due to the different sizes and densities of coffee beans. If you want more consistency between different types of coffee, consider one of the methods below.
Measuring Coffee and Water by Weight
In order to be truly precise, you should measure your coffee and water by weight using a kitchen scale. Simply zero out the weight of the container for your grounds and add the desired weight. Since the weight doesn’t change after grinding, you can use this method to measure coffee in whole bean form. The same holds true for measuring your water. You should know that one ounce of water weighs about 30 grams.
Although many professional baristas recommend a ratio of 1:17 for coffee and water respectively, I personally recommend 1:18, as I like a slightly cleaner cup (and the math is easier). To use either ratio, determine how much brewed coffee you desire, in grams. Then divide that number by 18 (or 17 for the stronger stuff). For example, to get 6 ounces of brewed coffee, you would start with 180 grams of water, divided by 18, which comes to 10 grams of coffee. I know it sounds complicated, but I promise you will get used to it.
Measuring by weight allows for consistency and precision across different brewing methods. You don’t have to worry about perfectly filling a tablespoon or watching the water level on your measuring cup. Instead, you just press a button on the scale and add weight until you reach your target. Once you get into the routine, you will discover that using a scale involves fewer steps and takes less time.