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| The Factors and Variables in Quality Espresso | |
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| A detailed look at what makes espresso so special. | |
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Home : Guides : Guide to Espresso : Factors in Espresso | Items in Cart: 0 | |
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When we defined espresso in the previous section, we gave a very accurate, yet simplified version of what is involved in making the cup. Espresso is as simple as you want it to be, or as complex as you want it. There are people all over the world who constantly seek to produce the more perfect shot, and because there are so many variables involved, for many, espresso truly is an art form, moving way beyond science.
Espresso is a demanding, torturous brewing method to the poor coffee bean. You are throwing scalding hot water at the beans and an incredibly high rate of pressure, and demanding perfect nectar in less than 30 seconds. Technology lets us do that, but it is attention to the variables, the factors that go into quality espresso, that turn good shots into great ones.
Here are some of the most important factors that go into making a quality shot of espresso.
Grinding for Espresso
At EspressoPeople, there is one thing we cannot stress importantly enough. The most crucial part of any high quality home espresso setup is the grinder. You can actually produce a much better espresso with a $200 grinder and a $150 espresso machine than you can with a $1000 machine and no grinder. We offer a complete guide to coffee grinders, and our hope is that you will read and benefit from it.
The reason the grinder is so crucial is because of the pressures involved in brewing a perfect espresso. The ground coffee has water thrown at it at incredibly high pressures, yet only dribbles out of the portafilter. How does this happen? The grind makes it happen. You grind the coffee so fine, it has a texture only slightly coarser than talcum powder, and the super dense bed of particles you place in the portafilter acts as its own "filter", restricting the flow of high pressure water, eating up all that energy that the high pressures throw at the bed of coffee. Where does that energy go? It goes into extracting the best solubles (solids that can merge with water) and flavor colloids (non-water extractable solids like oils; they may not "merge" with water, but they do come along for the ride), and lipids (these are fats that contain massive amounts of flavors) from the ground coffee, and bringing those goodies into your cup, all at a slow, thick dribble or stream of espresso.
A good grinder makes this kind of extraction better. A really good grinder has the ability to produce very uniform and microscopic slivers or shavings of the coffee bean, providing large (all things relative) surface areas for the water to extract the goodies mentioned in the previous paragraph. A lower cost grinder cannot produce these kinds of fines, and blade grinders are the worst of all. They don't actually grind coffee, producing the shavings that a good grinder can; instead, they literally pulverize the bean into tiny (and not so tiny) pebbles. Under a microscope, the difference is amazing. A good grinder produces elements that look like small, curled blades of grass. Blade grinders produce something that looks more akin to the surface of the moon - lots of giant boulders interspersed with tiny specks.
This is a Guide to Espresso Machines, and not a Guide to Grinders, so we'll stop here, but we cannot emphasize enough the importance of getting a good one. With that said...
The Build of a Modern Day Espresso Machine
Espresso has been defined in this Guide as a method of brewing coffee using finely ground coffee, and pushing high pressure water through the bed of coffee.
Let us provide a more concise breakdown of what is involved in making espresso, at least where the machine itself is concerned.
At its simplest, an espresso machine must do all of the following:
That's pretty much what an espresso machine is. The result of the list above is a machine that can commonly brew a double espresso shot in under 30 seconds. When you consider most automatic drip coffee makers take 8 or 10 minutes to brew, espresso is pretty fast, and therein lays another explanation for its name. Espresso, in a loose translation in French or Italian can also mean fast or quick.
We've thrown a lot of terms at you, and we promised at the beginning not to confuse you with a lot of scientific terminology. Sometimes it's unavoidable, and we hope you take advantage of the pop up glossary if you are unfamiliar with the terms. Here are the major types of espresso machines (later on, we'll go into greater detail about each type of machine and provide specific examples, but for now, let us define each major type):
Semi Automatic Espresso Machine: This is a machine that automatically regulates the activity of the water temperature for brewing and steaming. It also regulates the activity of the built in pump. It is a "semi" because it requires you to activate switches or buttons to change the machine's mode. The Gaggia Classic, Solis SL 70, and Saeco Classico are some examples of semiautomatic espresso machine.
Automatic Espresso Machine: This one confuses most people, because they may think automatic implies the machine does everything, including grinding, tamping, and disposing of the grounds. This isn't the case. An automatic is essentially the same as a semi-auto except that it automatically controls the volume of liquid poured to the grouphead of the machine. On many commercial automatics, this volume can be programmed. On most consumer automatics, it is preprogrammed at the factory. The Solis SL 90, Krups Artese Premium, and the Pasquini Livia 90 Auto are some examples of automatic espresso machines.
Super Automatic Espresso Machine: This is the newest form of espresso technology, and the machine that truly does it all. With one touch of a button, the machine will grind, dose out grinds, channel the grinds into an internal brewing apparatus, tamp the grinds down, deliver a precise volume of heated water at high pressures, brew the shot, then eject the spent coffee grounds into an internal chamber. The Saeco Vienna SuperAutomatica, Saeco Magic Comfort Plus, Solis Master 5000, Capresso C1000, and the Jura S90 are some examples of super-automatic espresso and coffee centers.
Manual Espresso Machine: It would seem to most folks that the machine defined above as a "semi-auto" espresso machine would be the manual one, where you grind your coffee separately and dose it, tamp it, and activate the brewing switch to make the shot. But that's not manual. A true "manual" machine is one in which you are the pump, either on an active basis, or a passive basis. Lever machines such as the piston lever La Pavoni Professional, or spring lever machines like the Elektra Micro Casa a Leva are manual machines. You move a lever, either to load a spring or to apply direct force to pushing water through a bed of finely ground coffee. The machine still does many things automatically, such as maintaining the water temperature, and monitoring low water levels, but you manually do something that applies forced water through mechanical means through the coffee. The La Pavoni Europiccola, La Pavoni Professional, and the La Pavoni Romantica are some examples of manual espresso machines.
Later on in this Guide, we will go into greater detail about each type of machine, and the models that EspressoPeople carries.
The Coffee Bean
In our previous section, we discuss coffee beans a bit, but in this section, we'll discuss more how different types of coffee and different types of roasts can produce different styles of espresso. There is, however, one overriding factor that must not be overlooked:
Use fresh, high quality, fresh ground coffee whenever possible.
Along with a quality grinder, nothing provides as big a leap in espresso quality that fresh roasted, quality Arabica coffee beans can provide. Roast types and bean types are important, but not nearly as important as fresh beans.
The coffee bean is a wondrous thing, and nature's most complex natural foodstuff. When coffee is roasted, it undergoes major chemical changes - the chemistry of the bean alters radically during the roasting process. One product of the roast is large amounts of carbon dioxide gas. Another product is a lipid. These are, in a literal sense, little flavor transporters that carry all the best possible tastes from the bean into the brewing water... which goes into your cup, and into your mouth where your tongue tells your brain "wow, this is something special". Carbon dioxide (CO2) also helps to transport these flavors, and gives them a tingle and tang that makes great espresso... well, great. CO2 also serves another major purpose - it is the prime builder and longevity producer for the crema that tops a shot of espresso.
So remember this: carbon dioxide and lipids are your friends when it comes to good espresso.
The problem with both of these elements is this - they always want to escape. Carbon dioxide is a virtual escape artist in fact. When coffee is roasted, it produces a lot of CO2, but a lot of the CO2 is lost after the roast through a normal process the beans undergo, called "degassing". This is a good thing - too much CO2 in the beans actually can ruin the shot. After about 24 to 48 hours after roasting, the CO2 release settles down, but still continues at a slow, but steady pace. This is the "sweet spot" for coffee... the next 4 to 7 days, the CO2 levels are excellent, and the lipids are happy in their shelled cocoons. But after 7 days, the coffee has expunged most of its allotment of CO2 gas, and that nasty corrosive oxygen leeches in and replaces it. This is when beans start to go stale.
CO2 has another enemy, of sorts - the very thing that is a must in producing great espresso - the grinder.
The act of grinding releases approximately 75 to 80% of the stored CO2 in a coffee bean within 2 minutes of grinding. This is why it is so crucial to grind just before brewing - you capture that CO2 in your shot, and the result is heaps of dark golden crema, and a silky yet tactile beverage that seems to linger on your taste buds for quite some time. That is the result of CO2 and the flavor lipid transporters doing their job. And they do their job best when you use fresh roasted, fresh ground coffee.
Now that the idea of fresh ground, fresh roasted coffee is seeded in your head, let's cover the types of beans and roasts a bit more.
You may have read or heard about different families of coffee trees - most notably Arabica and robusta coffees. Arabica beans are the original coffee beans found in Yemen and Ethiopia, and these are without a doubt the best quality beans on the planet. The Arabica coffee tree is a fragile plant, and it needs specific growing conditions to produce well - usually between 2,000 and 6,000 feet in elevation above the sea, and usually between the Tropics of Capricorn and Cancer. While Arabica coffee trees may be fragile, the beans they are capable of producing are amazing, and have low caffeine levels while literally exploding with a wide range of flavors and tastes.
Robusta beans are hardier beans that can grow in more diverse growing conditions. They are found in the jungles of Zaire, and the forests of Vietnam. Robusta trees can even grow in the southern United States with little or no effort. The price you pay with robusta is in a loss of taste, or a different taste that doesn't appeal to most people. Many robustas have a "rubber" taste, and seem much more astringent than Arabica beans. There are some quality robustas, but they are usually grown in areas suited for Arabica trees, and are better maintained and harvested. Robusta has a much higher yield of caffeine than Arabica does, and in most instant and other types of prepackaged supermarket coffees, robusta makes up 75% or more of the total coffee bean volume used. Italians often blend in some robusta with their Arabica blends to strengthen their blends (as well as to reduce costs - robusta beans are much cheaper on the world market than Arabica beans are).
Choosing, Roasting and Blending for Espresso
Remember in our previous section we dispelled the myth that there is a specific espresso bean, roast, or blend? That is true. Still, there is both an art and a science to choosing beans for espresso, roasting for espresso, and blending for espresso. We will not attempt to give you specific guidelines as to what constitutes the perfect espresso blend, but we will give you some background into why different craftsman roasters may choose different beans and different roast levels.
When choosing beans for an espresso blend, most roasters look for specific flavors. Chocolate, floral, grassy, cinnamon, spicy, fruity, these are all flavors found in different types of coffee. Even more challenging is this - specific coffees from year to year can change their primary flavor notes. For example, one year an Ethiopian Ghimbi bean may have tea-like notes as its primary flavor. The next year, it may be more on the grassy, lemony side of the flavor wheel. The next year after that, it could have chocolate notes.
This is why professional roasters cup samples of beans every year before making a major purchase. And this is why they may change the beans in their customized blends every year. If one bean isn't producing the same primary flavor note one year, they will find another bean from another region that produces the flavor they are seeking.
Roasting can affect the taste of a bean, and there are also regional likes and expectations to factor in. Thanks in a large part to Peets' Cafe, and also to Starbucks, the west coast of the US tends to favor a darker roast than the central US does. In Northern Italy, a medium (or "Full City") roast is preferred for espresso. In the eastern US, it's all over the board, with some people preferring a light roast.
Knowing the intended roast style means choosing an espresso bean that will be well matched to a roast style. For instance, a good Kona seems to be best when roasted to a medium roast. It is a delicate bean, and dark roasting seems to burn off most of the delicate flavors, leaving it lifeless and dull. Yet an Old Government Java seems to be mute and dull as a medium roast, but starts to release its nutty and floral flavors as soon as you make it into a medium-dark roast, or darker.
Conversely, if you want specific bean types, you have to roast according to that bean type. If you must have Yemen Mocha in your espresso blend, it must be roasted to a level that suits the Yemen bean, not to your preferred final roast.
Then comes the blending. A professional roaster will have specific goals in mind when blending for espresso. He or she may want specific flavors to shine, and other flavors to complement, and he or she will choose the best beans and best roasting levels to get those specific flavors.
Roasting is a very complex and artistic field with relatively few true experts, and the artistry is unsurpassed in the culinary world. With the wide variety of beans available to the roaster today, it's easy to see how complex producing the perfect espresso blend can be.
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