Raul Rodas is a world barista champion, a four-time Guatemala national champion, a buyer and quality consultant for some of the world’s largest coffee companies, and a business owner and roaster with his beloved Guatemala City shop, Paradigma Coffee Roasters. By the high standards of international coffee competition, he has literally made the best cup of coffee in the world.
“Coffee releases more or less gas or CO2 while you’re pouring water over it,” he said in a recent interview with Coffee or Die Magazine. “How much gas releases will affect or alter the different flavors inherent in the beans.”
Coffee quality, water quality, grind size, the ratio of coffee to water, water temperature, and the time on grounds all affect the off-gas and extraction process, Rodas said. Perfecting a pour over is about tweaking these variables until that cup of brown gold strikes your personal palate preference.
“There is no perfect formula, or perfect cup, even though we try to find it,” he said. “You can only do the best by the beans for your palate.”
Water, he said, is the main ingredient in every cup of coffee — and often the most overlooked. “Much of the flavor comes from the quality of the water,” he said. He tests water for a pH of 7 to 8.5 and a hardness of 50 to 80 parts per million for peak flavors and extraction. He said the excellent tap water in Guatemala City — and in many parts of the US — hit these numbers. Most bottled water is in the 4.5 to 6.5 range.
If this water science sounds complicated, it shouldn’t. You needn’t invest in lab equipment to make better coffee. If your water is good enough to drink right from the tap, use it. If it’s so-so, run it through a basic carbon filter like a Brita. But water is just one ingredient, one step. If you’re using a Chemex or single-cup system like a Hario V60, here’s how to tune each step to your palate and preferences, according to coffee pro Rodas.
“Finding your formula is part of the fun, part of the reward.”
Coffee. Buy fresh-roasted coffee. This is the single fastest, easiest way to make a better morning cup of joe.
Water. If you won’t drink your tap water, don’t make coffee with it. Use filtered water or jugged natural spring water. Stay away from bottled water, as the pH is too low and makes for too much plastic trash.
Grind size. Pulverize those fresh-roasted beans with a burr grinder for consistency, not a whirly-blade unit, which makes uneven grinds. Grind until the grounds are the consistency of beach sand. Coffeeheads call this a “medium” grind, and it’s an excellent place to start. Grind coarser if you detect any bitterness, as you might with dark roasts, or finer if you’re looking for a more extracted, richer flavor. Rodas says finer works best with lighter roasts.
Quantity. Start with the Specialty Coffee Association’s recommended ratio of 16-to-1, or 16 milliliters of water to every gram of coffee. Dropping the ratio makes a more robust cup (more coffee to water) while bumping the ratio lightens your beverage.
Filter. Use a natural (brown) filter, not bleached white. Make sure to wet it with hot water before starting the pour over process.
Heat. At sea level, water boils at 212 degrees, but most coffeeheads aim for a water temp closer to the SCA-recommended 200 degrees, Rodas said. At 5,000 feet elevation, the boil temp drops to 203 degrees, so tune your temperature to altitude and test. Modern electric pour over kettles like the Stagg EKG make this easy. But if you don’t want to drop almost two Benjamins on a kettle, a basic stovetop tea kettle with a thermometer works just as well. Darker roasts are more prone to bitterness with hotter water temps, so skew lower the darker the roast.
Time. This is the final dimension. With the filter wet and grounds ready for the pour, add about double the weight of the grounds in water and wait 45 seconds. That means, if you have 30 grams of grinds, add 60 milliliters of water, then wait to give the coffee time to bloom, or off-gas CO2. After that, pour the remainder of your water weight in 200-milliliter increments or so. With a Hario, this whole brew process should take about three minutes. With a Chemex, aim for three to four-and-a-half minutes, depending on the amount of coffee being made. Much faster than that is an indicator that the grind is too coarse; much slower, the grind is too fine.
For Rodas, this adds up to 32 grams of coffee, ground medium coarse or to the consistency of rough sand, with 500 ml of filtered tap water (that’s a 15.62-1 ratio) heated to 196 degrees and brewed no longer than three minutes.
This article first appeared in the Summer 2021 edition of Coffee or Die’s print magazine.
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