Mr. Hoffmann is the proprietor of Square Mile Coffee, a roasting company in London, and a six-stool, espresso-less coffee bar that closes this week after a temporary residence in the Shoreditch district. At the bar, named Penny University for the term applied to the first London coffeehouses, he and his colleagues offered a revelatory short course in the possibilities of brewed coffee. They presented a menu of three contrasting kinds of beans, brewed them using any of three methods, and chatted with their customers about the fine points of the ingredients, process and flavor.

Earlier this month I enrolled in a tasting of coffees from Kenya, Ethiopia and Guatemala, all roasted lightly to avoid losing their distinctive qualities in the intense but more generic flavors of a dark roast. Each cup was less concentrated than I’m used to making for myself, yet delicious and distinctive.

Mr. Hoffmann explained that industry standards for brewed coffee strength vary a great deal, from around 1.25 percent extracted coffee solids in the United States to something approaching 2 percent in Brazil and in specialty coffeehouses. He aims for 1.5 percent, and gets it consistently with the help of a precision water boiler and a digital scale on which he does the brewing, pouring water to the gram.

“It seems silly, debating decimals,” Mr. Hoffmann said, “but it makes a big difference to the flavor.” A tablespoon of water more or less can shift the extracted solids by a perceptible amount. It also matters how the coffee solids are extracted. Mr. Hoffmann told me that concentrated brews are often made palatable by using a lot of coffee and reducing the brewing time or the temperature to extract only the easy-going portion of its flavor materials. The result is intense but one-dimensional. More fully extracting a smaller amount of gently roasted, high-quality coffee, as Mr. Hoffmann and a number of new-wave brewing advocates are doing, brings out its full range of tastes and aromas.

“When I drink coffee I’m looking for clarity, by which I mean distinguishable, characterful, interesting flavors,” Mr. Hoffmann said. The lightness of his brews did seem to highlight their very different aromas, which changed but remained enjoyable even as the remains cooled to room temperature. “No other liquid I know evolves as much as you drink it,” he said.

I brought home some of Mr. Hoffmann’s Yirgacheffe, an Ethiopian coffee that I love for its unusual blueberry aroma, and measured my brewing against his with the help of a refractometer, a device that measures dissolved solids. (Refractometers are sold online beginning at around $50). I made a cup at my standard strength, which turned out to be 2.2 percent coffee solids.

When I dropped the strength close to Mr. Hoffmann’s preferred 1.5 percent by using a third less ground coffee (about 12 grams of coffee to 180 grams, or 6 fluid ounces, of water), the fruity aroma was much more evident, and the flavor generally brighter and more lively. Clarity is a good word for the overall impression.

So I’m making my coffee with more water now, and getting many more cups from a bag of beans.

You don’t need a refractometer to explore the power of dilution, though a scale is advisable for getting close to Mr. Hoffmann’s sweet spot for coffee, since volume measures are unreliable and the decimals count. If you’re in the habit of brewing strong cups from premium beans, then give his proportions a try, weighing out both coffee and water. Or, later in the day, pour a glass of strong spirits or a big wine and try adding some water. Or make one of Ms. Saunders’s inverted cocktails. And see whether the flavor you get is not so much watered-down as opened up, and good.