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Espresso Essentials
By Maura Keller

Visit any European café or bistro and you’re bound to find espresso that tastes very different from its North American counterparts. The reason? It’s simple. Part art, part science, making a perfect cup of espresso depends on the due diligence of a professionally trained barista and a refined understanding of the chemistry involved in espresso extraction.

Redefining Taste
A nuclear physicist by training, Dr. Joseph John, founder of Josuma Coffee, an importer, distributor and roaster of fine specialty coffees from India, has studied the art and science of making coffee for more than a dozen years.

“I am a frustrated coffee drinker,” John says. “Over the years, my wife and I would travel outside the United States one year and in the United States the next. We would find, particularly when you go to Europe, that you always get a good cup of coffee pretty much anywhere. You come back to the United States and you get warm brown water, not coffee.”

In fact, John says he would often go into the kitchen of European establishments to determine what they used to make their coffee. He discovered that every restaurant would have a different mechanism being used. Without discovering the “secret” behind their success in making an espresso, he became even more frustrated.

“Ultimately I gave up on coffee and became a tea drinker because I convinced myself I would never make a good cup of coffee,” he says.

But while conducting a study for the specialty coffee industry, John realized that one of the key attributes that has lead to the success of the industry is based on that the industry’s ability to make a good cup of coffee—at least better tasting coffee than what Americans are used to drinking.

“So once I was able to come to that conclusion that the whole crux of the specialty coffee industry is a good cup of coffee, then I started asking, ‘What is a good cup of coffee and how do you define it? Can you prove it?’” he explains.

After delving further into the fundamentals of coffee brewing and grounding, John determined that the real reason Americans were drinking such bad coffee and Europeans were not, simply was the result of Americans not being taught how to make a good cup of coffee.

“For years, the coffee industry was dominated by three companies, General Mills (Maxwell House), Folgers (Procter and Gamble) and Nestle,” John says. “They never educated the consumer as to how to make a good cup of coffee—especially espresso. By and large, the majority of Americans are still drinking what I call ‘supermarket coffee’—going to a supermarket and buying canned coffee and going home and making the same warm brown water."

Espresso is even worse. “As far as I’m concerned," John says, “what most of the espresso bars are making today in North America is not espresso at all. It is simply brewed coffee made in an espresso machine. Just because it is made in an espresso machine, does not make it an espresso."

Science vs. Art
Experts agree that the secret to coffee as a beverage is the understanding of coffee chemistry. “There is a large scientific component that baristas need to understand,” says Matt Milletto, consulting director and lead barista at Bellissimo’s new American Barista & Coffee School in Portland, Ore.

“Basically, the good parts of the coffee are extremely soluble in water, the part that you really want to get in your cup. By the time you run water through the coffee, all the good stuff has come out,” John says. “Now if you run the same water through ground coffee there is no more good stuff to come out. Instead, what you are going to do is to extract the bad stuff—the bitters, the acids, the caffeine. The weaker the coffee, the more bitter it becomes. The stronger the coffee, the sweeter it is.”

In other words, John says, Americans were never taught to use enough ground coffee.
“So it has nothing to do with the machinery or coffee-making device, it only had to do with how much ground coffee you were putting into the filter,” he says. “And the ratio of ground coffee to water will determine how good of a cup you are drinking.”

The scientific component of brewing coffee drastically affects the quality of espresso as well. As John explains, when you say brewed coffee, you are actually steeping ground coffee in hot water, in the process you are dissolving part of the ground coffee. In fact, roughly 18 percent to 22 percent by weight of ground coffee will actually go into the solution.

What’s more, it typically takes a certain amount ground coffee, say 7 to 9 grams, to make one 5-ounce cup of coffee. Here’s the interesting part: It turns out that the amount of coffee you would use to make a single shot of espresso is exactly the same.

“So in essence, whether you make one cup of coffee or one shot of espresso, you use the same amount of coffee,” John says. “There are so many similarities that I’m not surprised people confuse one with the other. For example the temperature of the water at which you make brewed coffee and espresso should be the same—namely, 195 degrees to 205 degrees F.”

In fact, the key difference in making brewed coffee and espresso falls within the amount of contact the ground coffee has with the hot water, the level of grind and the machinery being used.

“When you talk in terms of making coffee you are actually bringing the water in contact with ground coffee for some period of time between one minute and four minutes,” John says. “For example, it is one minute for drip coffee and four minutes for French press. So depending on what type of coffee you are making, the time of contact of water with ground coffee is different.

“The rule of thumb is the shorter the period of contact, the finer the grind,” Milletto says. In the case of espresso you are talking about 30 second exposure, which means the ground coffee has to be ground finer for espresso than for brewed coffee.

“The biggest difference between brewed coffee and espresso is that you need an espresso machine to make espresso and all you need is a kettle and a filter to make coffee,” John says.
In fact, the espresso machine performs three key tasks:

1. It heats up water.
2. It pre-measures the amount of water that it delivers.
3. It delivers that water under pressure.

The reason why you need the pressure, is that, in addition to extracting the solubles, you also need to emulsify the oil, which actually makes the espresso.

“Since you are extracting the same amount from the coffee and since you are using the same amount of ground coffee to begin with, the espresso would be five times stronger since you are extracting the same amount into one ounce of water for espresso versus 5 ounces for brewed coffee,” John says.

But most importantly you have to emulsify the oils because that completely changes all of the properties of the beverage. The emulsified liquid has the oil and the coffee consummate in it and it is that combination that makes a good espresso.

In fact, the oils in espresso drastically affect the way you taste. Here’s why: The oil will coat your taste buds and, as a result, the ability to taste bitterness is diminished. “The second sip of espresso will always taste sweeter than the first sip,” John says. “More importantly, if you were to produce brewed coffee and honest-to-goodness espresso with exactly the same blend, you will find the espresso to be sweeter.”

John and Milletto agree that the general public has been trained the wrong way. “Less that 5 percent of what is being consumed is true espresso. The rest has to be buried in milk and sugar and flavored with cinnamon and chocolate in order to be drinkable,” John says.

There are good reasons why the industry is not doing it right.

1. People don’t understand what an espresso is. They have not been exposed to proper espresso produced in locales such as Italy.
2. Most baristas have been trained only partially, by people who don’t understand espresso.
3. Many roasters also don’t understand espresso and so they often blend for espresso just like they blend for brewed coffee.

Of course, the quality of the water is essential in making a good espresso, Milletto says.
Ninety-eight percent of what you drink for brewed coffee is water. In the case of espresso you are exaggerating all of the properties. Good water is a prerequisite to making good espresso.

The Nose Knows
So why is real espresso so good? As John explains, a big component of espresso flavor is the aroma. “Your nose detects the flavor,” he says. “In fact, only 20 percent of the information comes from your tongue, 80 percent comes from your nose. So when it comes to brewing coffee or making espresso, your nose plays a key role.”

Let’s take a closer look at the importance of the aromatic component of espresso. When you bring hot water into contact with coffee, you are dissolving some components of the coffee, while at the same time releasing some gases, which contain the aroma of the coffee. The way people make espresso is exactly the same way.

“Since they are only making brewed coffee, not true espresso, there is no intrinsic mechanism to capture the aroma and keep it in the cup,” John explains. “The aroma escapes from the espresso machine and fills up the café and out the front door and onto the sidewalk, which may be a great way to get people to come into the café, but when they come in and get an espresso, the aroma that they expressed is not there anymore.”

However, in the case of a true espresso there is an intrinsic mechanism. Here’s why: The production of the oil particles at the time of extraction occurs at the exact time the aroma is released. “The oil bubbles consist of a film of oil on the outside and the aromatic compounds are on the inside,” John explains. “They are held together by the bubble. If you emulsify the oil, when you are producing an honest-to-goodness espresso, you will get crema, whether you like it or not. When making a real espresso, everything coming out of the portafilter should be crema, which should fill up the cup. As the cup fills with crema, the liquid concentrate coffee should separate out from the bottom.”

Now the bubbles within the crema contain all the aroma of the espresso. Rather than being released in the air, the aroma of espresso is captured in those bubbles and kept in the cup.

“Furthermore, when you drink the espresso, you are creating a lot of turbulence in your mouth,” John says. You don’t want these bubbles to break in the front of your mouth, you want them to break in the back of the mouth since it is connected to your nose. If they do that, then the aromatic compounds are being released and can escape into your nose. You will be getting the aroma in the mouth and in your nose. These bubbles will stick to your taste buds and remain in your mouth for hours. “With a good espresso, a consumer should taste it for two hours. Called the aftertaste, that is what a good espresso is,” John notes.

Vital Components
Milletto says that the beans used in making espresso play a key role in the quality of espresso being produced. He says that there are several grades of beans that work well for espresso. Single-origin espresso beans such as Kenya AA, are exceedingly popular with serious coffee drinkers.

“The type of beans used are subjective to people’s taste,” Milletto says. “Blends also make a good espresso, with seven to nine different beans that are combined to accomplish a taste profile and give complexity to the espresso.”

Milletto and his barista colleagues recommend the use of semi-automatic espresso machines. “These machines allow the operator to have control over the quality of the espresso being made," he says.

Also, when grinding the beans, Milletto says it’s important to stay on top of the grind throughout the day, as the grind may change several times a day as a result of changes in barometric pressure and humidity. If a barista notices changes in extraction time, that is a clear indication that grind setting needs to be adjusted. However, the pressure tamping should always remain the same: approximately 30 pounds of pressure.

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