He waved a bottle under my nose and asked me what it smelled like. I said flowers, but that's wasn't specific enough. It was the essence of coffee blossoms. He tried another one. I guessed hazelnuts. It was actually basmati rice. My future as a coffee taster is apparently bleak.

Katz says he drinks medium-roast Guatemala Antigua at home. Dark-­roasting great coffee beans is like cooking a Kobe steak well-done, he says.

What's his advice for Houston coffee drinkers? "Forget about brands; buy fresh, locally roasted coffee. Freshness is everything," he says. "Buy coffee like you buy bread; get just enough for a week at a time."

Katz says grinding your own beans is a must. "Did the waiter at a steakhouse ever walk over to your table and say, 'Would you like some dried-out previously ground pepper?' I don't think so. When you grind your beans just before you brew, you improve the flavor of your coffee 100 percent."
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To understand the significance of Houston's New York Board of Trade green coffee bean port certification, think of the movie Trading Places, the one where Eddie Murphy goes from being a bum to being a commodities broker. Commodities brokers buy and sell contracts to deliver goods at a set price, betting on fluctuations in supply and demand.

The plot of the movie centers on frozen orange juice futures, and the ending involves a run on the market, with wild action in the trading pit as the price of orange juice futures goes up and down. To guarantee that futures contracts are fulfilled as promised, the New York Board of Trade certifies ports and warehouses where the commodities can be tracked.

Commodity-grade green arabica beans are currently selling for around $1.40 a pound on the New York exchange — robusta beans are at 70¢. Coffea canephora, or robusta coffee, accounts for about a third of world production of commercial coffee, and is of lower quality than Coffea arabica, or arabica coffee, which makes up the rest.

Arabica is one of the costliest agricultural products in the world. All premium coffees are made of 100 percent arabica beans, but there are many grades of arabica. Specialty and premium grades are used in expensive gourmet coffees; commodity grade is used in commercial blends.

Grown at sea level, the robusta bush is harvested mechanically, with beans at varying stages of maturity and ripeness all mixed together. It's typically dried on the ground, so the beans absorb the flavor of the dirt. Arabica coffee, on the other hand, has lovely fruity and floral aromas and a bright taste thanks to a balance of roasted flavors and high acidity. It's grown at high elevations, picked by hand as the cherries ripen, and cured and dried by one of several labor-intensive processes.

So where does all the robusta go? It is often used in espresso blends for its excellent "crema." Some like it for its high caffeine content. "Some supermarket coffees are 100 percent robusta," says de Aldecoa. Typical supermarket coffee blends contain around one-third robusta beans.

"Blends are dynamic; they respond to the market," says de Aldecoa. "Big brands are constantly changing their blend with the goal of keeping the flavor exactly the same." When the price of beans from Brazil goes up, you look for a bean with a similar profile from Central America or Mexico.

Most of us think that opinions about aroma and flavor are subjective, but they're not in the world of coffee. You can weigh the beans, measure their size, check their color, look for defects and even perform chemical analysis of caffeine content. But in the end, it's a trained coffee taster's sensory perceptions of flavor and aroma that will determine what the beans are worth and how they will be used. Coffee tasters undergo formal training and must be able to distinguish distinct coffee aromas and flavors according to a highly codified glossary.

"Coffee roasters are like chefs," de Aldecoa explains. "We have to choose a roasting technique to bring out the best in the beans." In this analogy, high-quality arabica beans are the prime steaks, and you roast them very quickly at high temperatures to medium doneness to preserve all their wonderful natural flavors. Cheaper beans, like cheaper cuts of meat, can taste great if you cook them slowly. And Vietnamese robusta beans, like stringy fajita meat, are dark-roasted to mask the defects.

In 2007, Kraft changed the Maxwell House blend to 100 percent arabica beans in a companywide effort to improve quality. Community Coffee is also labeled 100 percent arabica. But there is no enforcement of labeling laws. Coffees labeled Kona blend might contain as little as 2 percent Hawaiian coffee. Kona-style coffees often contain no Hawaiian coffee at all.