There is nothing better than enjoying a nice cup of coffee when you first wake up in the morning—or just about anytime, for that matter. A good friend of mine says there is no such thing as a bad cup of coffee, but I have to disagree. A lot of details have to align properly before one can savor a tasty cup, and this is even truer when speaking of espresso. Odd, since the Italian word “espresso” translates to “express.”
When we experience good coffee, what we are enjoying are several compounds that have been released into the water during the brewing process. We first notice the distinct aroma of freshly brewed coffee. That great smell comes from the soluble, volatile materials as they evaporate. It is the soluble, non-volatile materials that give coffee its flavor or taste. The body—or how it feels in the mouth—comes from tasteless, non-soluble, non-volatile materials. However, a lot of factors must come together to achieve pleasing aroma, taste and body, so it is best to start at the beginning.
COFFEE BEAN BASICS
Coffee beans start life as the seed of a cherry-like fruit produced by coffee trees. The fruit begins as a flower-like blossom, which lasts only a few days. When the flower dies it leaves behind a small green coffee cherry. The cherries turn from green to yellow, and finally to a deep red—almost black. At this point the cherries are ready for picking, usually by hand—a very labor-intensive process.
As with many other types of crops, once coffee cherries have been picked, they must be processed quickly to avoid spoiling. The fruit is removed from the seed in one of two ways. The dry method is simply to dry the cherries in the sun. Once dried, the fruit is then separated from its husk, typically by a mechanical husker. The wet method involves using water and rotating drums to separate the beans by weight and size. Once the beans are dried, they are ready for roasting.
Coffee beans come in two basic types: Arabica and Robusta. Arabica beans are known as high-altitude beans because of the areas in which they thrive. The Arabica beans yield the best taste and are the most aromatic. However, they have about half the caffeine of Robusta beans. (Additionally, espresso has less than half the caffeine of drip coffee because of the shorter time that the grounds are in contact with the water.) Arabica beans make up 75 percent of the world’s coffee trade, but less than 10 percent of them meet specialty coffee standards.
Robusta beans grow at lower elevations and are said to be easier to grow. Robusta beans generally produce a woodier flavor. They are less expensive and are a good choice when additional caffeine is desired. Small quantities of Robusta beans are added to most Italian blends for the additional crema, or foam, they offer. In fact, mixing together beans grown in two or more locations often produces the best taste. Combined, they balance each other, giving the best flavor, aroma and body.
DECAFFEINATING THE BEANS
There are three methods used to decaffeinate coffee beans, a process that removes up to about 96 percent of the caffeine from the bean. The “conventional method” soaks the beans in a chemical solvent to remove the caffeine; however, this practice has been discontinued for obvious health and taste reasons.
Taste-wise, the Swiss water method is the preferred way of doing things now. The beans are soaked in hot water, which draws out the caffeine and the flavor of the beans. The hot water is then run through a carbon filter, which traps the caffeine. New beans are added to the water until it is saturated, and the caffeine is again filtered out. The saturated water, without the caffeine, is then preserved with all its wonderful coffee flavor.
The CO2 process decaffeinates using pressurized and chilled liquid carbon dioxide. The CO2 method is best used for high volume rather than for producing a fabulous-tasting cup of coffee.
ROASTING THE BEANS
Drum roasting, as the name implies, employs a gas- or wood-heated drum to rotate the beans as they are roasted. Temperature, drum speed and roasting time, among other factors, greatly affects the roasting result—and therefore the flavor of the coffee. The experienced roaster closely watches the beans for color and cracking to determine when the proper roast is achieved. The roasted beans are then cooled to prevent continued cooking. There is no substitute for experience when it comes to roasting, because it requires both precision and consistency.
An alternate method—air roasting—roasts the beans as they tumble on a hot airstream, and is not widely used.
The length of roasting time determines the darkness of the roast. Light roasts generally have a sharper, more acidic taste, while the darker roasts offer bolder flavor. However, the darker the roast, the more you will begin to taste the char rather than the true flavor of the bean. Super-dark roasts yield a smoky flavor, and they are better suited for drip coffee than for espresso, which generally favors a medium roast.
Roasted beans exposed to air begin deteriorating immediately. If properly stored, some experts say the unground beans will stay fresh for only 7-10 days, but others insist that they will be fine for up to 25 days. For the best life expectancy, coffee beans should be stored in an airtight container, and in a cool, dry place that is protected from light. Do not store them in the refrigerator, as the beans will absorb ambient flavors. When buying beans in non-airtight packaging, ensure that the roast date is noted on the bag.
GRINDING THE BEANS
How coffee is ground has great impact on its flavor and appearance. This is especially true for espresso. Good espresso cannot be made without a good-quality grinder that produces a consistently even grind. Look for a grinder with stepless adjustment, which will allow you to make slight adjustments to the grind. Coffee beans should never be purchased pre-ground, but instead should be ground just prior to brewing. Once the coffee beans have been ground, they immediately start to lose their flavor and aroma.
The grind controls the exposure time—or how quickly the water passes through the coffee. If the grind is too coarse, the water will pass through too quickly—and the result will be a sour, weak, watery taste. If the grind is too fine, the water will pass through too slowly, producing a bitter taste. The acid is the first thing extracted from the coffee beans, followed by sugar and, eventually, caffeine.
You will need to monitor your grind constantly. A coarse grind, with distinct coffee particles, is what you want for a French press coffee maker. A medium to fine grind, which is similar to the texture of sand, is typically used in drip coffee makers. A fine to super-fine grind, as described below, is used in espresso machines.
“ESPRESSO” THE BEANS
Espresso requires a very fine, consistent grind. An easy test is to pinch the grind between your thumb and forefinger. The coffee should clump in the center of the pinch area, where the pressure is greatest, but not at the edges. No clumping means that it’s too coarse, and if the entire pinch clumps it is ground too finely.
Great espresso requires, at the very least, a decent espresso brewing machine. You will need a machine capable of delivering the correct amount of pressure through a cake of finely ground and compressed—or “tamped”—coffee beans. Cheap, steam-powered machines generally do not fill this requirement. A much better choice is a pump-, or piston-driven, espresso machine. Good home electric pump-driven espresso machines are available for under $300.
Last but not least, water purity cannot be overlooked. Since espresso is about 90% water, the quality of your water is key. A water filtering system is crucial, especially if your area has hard water. Unfiltered water will affect both the taste of your espresso and the life expectancy of your espresso machine. Bottled water often works well for a home machine.
HOW TO MAKE ESPRESSO
The first step is to warm up your espresso machine. Any part of the machine that comes into contact with the coffee must be preheated. This means the brew head, the coffee handle and the portafilter—or the cup—and even the tamper should be warmed. Typically, this is done by running a few ounces of water through the head to prime the pump and boiler. But at this stage, the water isn’t hot yet. Once the machine is hot, run two ounces of water through the brew head (with the coffee handle attached) to warm those items.
Now we are getting to the fun part: Firmly pack, or tamp, your finely ground beans with a hand tamp, using between 30 and 40 pounds of pressure. The goal is an even, level surface and consistent packing. This makes certain that the water will go through the grounds evenly. Do not place too much coffee into the basket, as there must be room for expansion. A gap is needed for the water to spread evenly over the surface of the grounds. Remove any excess grounds from around the edges of the basket to ensure a proper sealing, and to prevent damage to the rubber gasket located inside the head.
The thickness of the “crema,” or the foam on your espresso, determines the perfection of the espresso. Judge your shots by the color and the crema. Your goal is to extract a rust-colored crema that lasts for a long time. Extraction of shots should start out as a “drip, drip” and then continue as a pouring in a syruplike consistency about the width of a strand of angel hair pasta, lasting anywhere from 20-26 seconds.
The presence of crema means you are within range of having the variables of temperature, pressure, tamping, and so on, perfected. Espresso is not meant to be all crema, but to have a layer of about one-tenth crema. It makes the espresso visually pleasing, while adding aromatics, body, flavor and a long-lasting aftertaste. The crema should last about two minutes before the suspended water molecules drain, the entrapped gas is released and the liquid underneath shows through.
MILK & ESPRESSO-BASED DRINKS
When steaming milk for milk-added drinks, avoid pumping the milk full of water while steaming, or overheating and scalding the milk. The water problem occurs when the machine has run out of steam, and instead just sprays hot water into the milk. Scalding milk is easy to do with commercial machines, but it is difficult using a home machine that has a limited amount of steam. You will want to pour the shot first and steam the milk second, so that you can pour the milk right after steaming. This way you will have “wet” foam; that is to say, foam that hasn’t separated into hot milk capped with stiff foam. If the foam must be scooped out with a spoon, then it is too dry.
There are two phases to steaming milk properly. The first phase is “stretching,” or introducing air into the milk to add texture. During the second “steaming” phase, the milk is heated to bring out its caramelized sugars. Properly textured and steamed milk will enhance the flavor of the entire beverage, bringing out the sweetness in the espresso, and will deliver an almost dessert-like quality. Whole milk interacts best with the coffee to bring out the wonderful flavors of both.
For best results, always start with cold milk and the correct-size pitcher for the amount of milk being steamed. Keep in mind when pouring your milk that it can expand with steaming to as much as double the original volume. Start by purging the steam wand, and then start introducing air up to 100 degrees. This is achieved by holding the steam tip just under the surface of the milk, or “stretching.” Next, “roll” the milk by plunging the steam wand entirely into the pitcher, creating a rapid, swirling circulation. Bring the temperature up to 140 degrees. Finally, knock out any bubbles by tapping the bottom of the pitcher on the counter, swirling the steamed milk to prevent separation.
Don’t bob the pitcher up and down, move it in a circular motion, or set it down while steaming. Inexperienced baristas often produce large, dry milk bubbles that must be spooned on top of espresso when the barista attempts to make a latte. The goal is to create fine, velvety, small-celled, textured, foamed milk.
So, the next time you stop in at your local coffeehouse or that roadside diner, you’ll know just a little more about what goes into making this deceptively simple beverage—be it espresso, cappuccino, decaf, or just a plain old cup of joe.
TRADITIONAL EXPRESSO RECIPES
Espresso: A single, straight shot.
Doppio: A double shot, usually served straight.
Americano: Espresso combined with hot water for a richly flavored coffee. Sometimes drip coffee is referred to as Americano.
Ristretto (restricted shot): A shot pulled short, leaving it with more fast-extracting compounds, and generally more concentrated.
Lungo (long shot): A shot pulled long.
Macchiato: A straight shot with a dollop of steamed milk. At most, there is 1 ounce of milk on a 2- ounce double espresso.
Con Panna: A straight shot with a dollop of whipped cream.
Cappuccino: Traditionally made with 1/3 espresso, 1/3 milk and 1/3 foam. Cappuccinos are generally served in a 5.5- to 6-ounce cup.
Dry or Wet Cappucino: This refers to the ratio of milk to foam. More milk is wet; less milk is dry.
Latte: Generally 1 part espresso to 3 parts milk. Techniques vary—sometimes the espresso and the milk are added simultaneously and sometimes the espresso is added to the milk. These days, often the milk is added to the espresso, allowing the barista to create designs on top.
Cafe Au Lait: Equal parts brewed coffee and steamed milk.