Philosophically Perfect Cup of Coffee:

© 1983 Stuart Daw
(published in Tea & Coffee Trade Journal, March 1983)

The National Coffee Service Association is developing a new operations manual. I have been asked by the board of directors to prepare a section dealing with coffee brewing standards around lines established by the Coffee Brewing Center in the days of the Golden Cup Award.

Many readers will recall the brewing standards one had to meet in achieving success in that program. Winning a Golden Cup had nothing whatever to do with flavor quality, only strength as measured by the percentage of solids in solution at a given ratio of coffee to water.

You will see in the accompanying diagram the form used in determining whether or not a food service outlet would qualify for a Golden Cup. As a sign of the times, I have extended the form 50 percent lower to have regard for weights of coffee currently in use in Coffee Service, something never even contemplated by the Coffee Brewing Center. Everything below .80 percent soluble solids in solution is "New Chart."

On the left hand side of the chart, the numbers stand for the percentage of a given cup of coffee that is coffee oil (soluble solids). The difference between that number and 100, is the percentage of water in that cup of coffee. Across the top of the chart and down the right hand side, you will see numbers that represent the amount of coffee used per decanter in a given brew.

The line that represented the bottom perimeter of the old chart represents the weight of the number of ounces of coffee oil per pound of coffee that had been extracted during brewing.

By knowing the amount of water and ground coffee used in preparing the brew, a soluble solids test done either by a hydrometer, a conductivity meter, or in a drying oven, would reveal the percentage of soluble solids in solution. Thus you can pinpoint on the chart precisely where the cup in question belongs, and then by running your eye vertically down the page, you can see the rate of ounces of coffee oil per pound that is represented by that particular cup.

As you can see, the old form shows that it would be impossible to win the Golden Cup with less than 3.2 ounces of coffee per decanter. If you look at the left hand side of the chart, that means that an "ideal" cup of coffee had to be between 1.15 and 1.25 percent soluble solids. In other words, at 1.2 percent soluble solids, a cup of coffee would contain 98.8 percent water.

If you use 3.2 ounces of coffee to a decanter, the extraction rate would have to be perfect in order to get precisely 1.15 percent soluble solids in solution, for too much or too little extraction would send you into either the "bitter" or the "weak" section.

Coffee brewed to the necessary specifications was rich indeed. And "forcing" the food service outlet that wished to benefit from the fine public relations flowing from the award to serve "coffee with some guts in it" was probably very good for the coffee business.

But with today's package weights it would be impossible to even get onto the chart let alone into Golden Cup territory. Is it then an absurd idea to even try to dignify today’s weights with a word such as "ideal?"

As I said in the September 1982 issue of' the TEA & COFFEE TRADE JOURNAL, the type of coffee represented by the Golden Cup standard should be thought of as the "philosophically perfect" brew. But the correct "socially objective" strength is that which satisfies the most people in any given environmental context, whether a hotel, restaurant, or business office.

At any strength the rate of extraction should remain the same. One can make coffee weaker than the "philosophically perfect" brew by using more water in the brewing process, in effect adding water to the "perfect brew." For if we simply add a decanter of water to a brew that has been made at 3.5 ounces, we have, in effect, brewed at 1.75 ounces, a fair weight in today’s OCS market. A hydrometer test of both brews will show the result as having simply gone vertically down the chart, as the percentage of solids extracted from the grounds would remain the same.

To the mathematical purist, forgive the poetic license taken in the preceding paragraph. In fact, 3.5 ounces of coffee would lose seven ounces of water in the brewing process. Then by adding a full 64 fluid ounces that would not actually pass through the grounds, we would more than just double the ratio of water to coffee.

To fit the old chart to modern reality, let us enter the "socially objective" strength for different types of eating places requiring different beverage qualities in the away from home market, and give "CUP" awards accordingly.

If you look at the chart vertically from the ideal range on down, you will see that we have assigned numbers to the cup in each rectangle, and herewith you will see a suggested scale of awards to be given in accordance with the various strengths involved.

* Cup No. I — The Golden Cup Award
(for the philosophically perfect cup of coffee)
* Cup No. 2 — The Silver Cup Award
(for normal restaurant use)
* Cup No. 3 — The Tin Cup Award
(light snack bars, high class business offices, etc.)
* Cup No. 4 — The Plastic Cup Award
(for ordinary business offices)
* Cup No. 5 — The Paper Cup Award
(for weak coffee oriented offices)
* Cup No. 6 — The Empty Cup Award
(for that chiseling competitor)

The chart below is based on the original "Golden Cup Brewing Control Chart" as issued by the Coffee Brewing Institute (later the Coffee Brewing Center), which has been slightly modified in current usage by the Specialty Coffee Association of America for their registered name, "Golden Cup."