What Is Espresso and What to Look for in the Perfect ShotPublished on 05/22/2023 · 16 min readCheck out this guide for a breakdown of all the steps that go into a perfect shot of espresso, as well as some tips to make sure you get the perfect shot every time!
Photo by Nathan Dumlao
Espresso is a coffee product created by forcing hot water through finely-ground coffee beans under high pressure. The process creates a strong, concentrated coffee typically served in small portions simply named “espresso” or used as a base for other coffee drinks like lattes, cappuccinos, and Americanos. The espresso brewing method was first patented in 1884 by Angelo Moriondo, an Italian inventor; however, it wasn't until 1901, when Luigi Bezzera, another Italian engineer, made further improvements to the machine and the method, that modern espresso was born.
Espresso is different from other methods of brewing coffee. Unlike drip coffee, brewed coffee, or French press, espresso uses high water pressure to extract more intense and complex flavors from the coffee grounds. This results in a more concentrated and potent coffee that can be enjoyed on its own or combined with milk or milk alternatives, syrups, or other flavorings to create espresso-based drinks.
From the origin of the beans to the final volume of coffee extracted there are a lot of factors that go into creating great-tasting espresso. Let’s take a look at what it takes for a barista to pull that perfect shot of espresso.
Chasing the Perfect Shot of Espresso
Start With the Right Beans
When it comes to the beans used for espresso, the two main types are Arabica and Robusta. Arabica beans are considered higher quality because they tend to have a more complex flavor profile with fruit, sugar, and nuts notes. They are also less bitter and have a higher acidity. Because they are grown in higher altitudes, they have a shorter and more volatile growing season, and the terrain is often too irregular for mechanical harvesting. These environmental factors mean Arabica beans are grown by smaller family or estate-sized operations.
Many single-origin bean roasts come from these types of growers and are considered prestigious the way certain varietal wine grapes are regarded. Arabica beans are grown in many parts of the world, including Central and South America, Africa, and Asia. Brazil is the largest producer of Arabica beans, followed by Colombia and Ethiopia.
Robusta beans are primarily grown in Africa and Asia, with Vietnam being the largest producer. They are grown in lower-altitude flatlands and planted in very regular rows, so larger, more industrial farming operations prefer them. Flat land and regular rows invite mechanical harvesting, and growers can produce a lot of Robusta on a scale that makes it less expensive than Arabica beans.
Robusta beans are known for their strong, bold flavor with chocolate notes and higher caffeine content. They are often used for instant and discount coffee and as the base for that “high octane” stuff at the truck stop. This is not to disparage Robusta, many espresso blends contain a combination of both Arabica and Robusta beans to balance out the flavor and provide a good crema.
Small-batch roasters make the best beans for espresso. They are freshly roasted and high quality. Of these, the most prestigious are usually single-sourced Arabica beans. These beans come from one estate or a particular portion of a grower's estate. Like high-quality and rare wines, much of the provenance of a coffee bean has to do with the exact location it was grown. There are many Arabica-only blends and Arabica-Robusta blends that are high quality.
Once a barista has secured some high-quality beans, they need to turn their efforts to pull the perfect shot of espresso. When brewing for the perfect shot of espresso, there are several factors to consider. Of course, the barista is already using high-quality, freshly roasted beans. Still, they also need to grind those beans specifically for that espresso and their brewing device, as the grind size and consistency can greatly affect the taste of the final brew.
Consistent Grinding with a Quality Burr Grinder is Essential
The grind of the coffee beans affects the taste of espresso because it affects the extraction rate of the coffee. Extraction is the process of pulling out the flavors, aromas, and caffeine from coffee beans. The grind size determines the surface area of the coffee beans that come into contact with the hot water during the extraction process.
A fine grind will have a higher surface area and extract more coffee solids and flavors, while the coffee takes longer to pass through, resulting in a stronger and more intense espresso with a thicker crema. On the other hand, a coarse grind will have a lower surface area and extract fewer coffee solids and flavors while the water runs through it faster, resulting in a weaker and more diluted espresso with less crema.
One of the most important steps in achieving the perfect shot of espresso is dialing in the grind's coarseness. A grind that is too fine can cause the espresso to be over-extracted, resulting in a bitter taste. A grind that is too coarse can cause the espresso to be under-extracted, resulting in a weak and sour taste. The goal in extraction is to expose a perfect amount of coffee grounds (usually 19-21 grams) to just the right amount of water for the right amount of time (about 26 seconds). A quality espresso machine will force water through the portafilter—the device with the basket that holds the ground coffee while the water is forced through—at the same rate each time. Hence, a barista uses the grind profile to adjust exposure.
Confused? Let’s try this analogy.
You have a bucket with holes in the bottom, and your goal is to make water flow through at just the right speed—not too fast, not too slow. You have a variety of sizes of materials you can fill the bucket with, ranging from very fine sand to rocks so big only one will fit in the bucket. If you aim for a medium water flow through the bucket, the large rock won’t do. The water runs right past the rock and drains right away. On the other hand, the finest sand will make the water drain very slowly.
Your best choice in this analogy is something like medium-fine gravel. When you fill the bucket with gravel, the water drains through slower than with the big rocks, but not as slowly as the sand. If that gravel is espresso beans, we have just created the correct exposure or passed the right amount of water by the correct coffee surface area over a precise amount of time. All of this is to say the right grind size is important for achieving the optimal balance of taste, aroma, and body in the espresso. A high-quality burr coffee grinder is the tool that baristas use to adjust their coffee between fine (sand) and coarse (rocks).
The most discerning baristas use high-quality stepless burr grinders. Stepless grinders have an infinite number of grind adjustment settings, as opposed to stepped grinders with limited settings. This allows for more precise control over the grind size and allows the user to make small adjustments to achieve the perfect grind for their specific coffee beans and brewing method. Burr grinders are superior to blade grinders because they use two abrasive surfaces (burrs) to crush the coffee beans rather than chopping them with a blade. This results in a more consistent grind size and less heat buildup, which can affect the taste of the coffee.
So far: The perfect espresso shot requires high-quality beans and a stepless burr grinder. These two items are essential for the barista to have a greater degree of control over the bean flavor profile and the grind size, which leads to a more consistent and precise extraction, and a better taste in the final cup.
Clean, Pure Water at Just the Right Temp
Next, the water used for brewing should be of good quality and at the correct temperature. The water should be between 195 and 205 degrees Fahrenheit and free of any impurities that could affect the taste of the coffee. Hard water or water with a high mineral content can negatively affect the taste of the coffee and often even permanently damage the machine. Using filtered or purified water is important to ensure the best possible taste.
Pick a High Quality (Not Just Expensive) Espresso Machine
The machine used for brewing the espresso is important, but maybe not as much as it seems. Most people think the brewing machine must be the most significant piece of equipment when making espresso, although many baristas would argue the grinder affects quality and flavor more than anything. Nonetheless, a well-made machine will always get better results than something constructed of inferior components. Any high-quality espresso machine can maintain a consistent temperature and pressure throughout the brewing process. It should have a built-in pressure gauge, a thermometer, and a temperature control system. The machine should also have a quality portafilter, which holds the coffee grounds and controls the pressure and flow of the water. There are many types of heating methods and mechanisms available in espresso machines, but the dual-boiler system is often considered the best.
Dual-boiler espresso machines are considered superior because they allow for separate temperature control of the brewing and steaming processes. In a single boiler machine, the same boiler is used for both brewing and steaming, leading to temperature fluctuations and inconsistent results. With a dual-boiler machine, each boiler is dedicated to a specific task, so the brewing temperature can be kept at the optimal level for extracting flavors from the coffee beans; the steaming temperature can be kept at the optimal level for creating frothy milk. This allows for greater consistency and control in the final cup.
This is not to say that owning a dual-boiler machine and a stepless burr grinder will get you great coffee. An unskilled barista can make lousy coffee on any machine without being trained on a good repeatable process. (Conversely, a skilled barista can make good drinks on something as affordable as a $30 Aeropress.) The right machine for a person depends on their personal needs, and often the most expensive thing is not actually a good fit. It’s good to consult an Expert when trying to determine “how much machine” you need because it varies from person to person. No matter what you choose, however, you will need a reliable and repeatable espresso recipe (or process) if you are going to get good results.
Practice (and Process) Makes Perfect Espresso
The technique used by baristas is crucial. Baristas should have a good understanding of the brewing process and be able to make grind and volume adjustments as necessary to ensure the perfect shot. This includes the tamping of the grounds, accurate weighed dosing of the portafilter, and the timing and measuring of the extraction. It might sound like a lot, but once a machine is dialed in, and with a little practice, the average barista can make a drink in under one minute. Here is how.
Professional baristas recalibrate, or “dial in” their grind and dose several times a day. For the home barista that is probably excessive, but they should dial in regularly (at least once a week) and whenever the flavor of the espresso seems off.
To dial in, a barista uses precise measurements in order to fine tune the extraction of the flavors and caffeine from the ground beans. Extraction occurs as the pressurized water is forced through the grounds, and it should take about 26 seconds (plus or minus depending on the exact roast of beans) and always between 20-29 seconds. Any longer or shorter, the shot may be under or over-extracted, resulting in poor taste. The final result should be around 1.5 ounces of espresso in the pitcher for a standard “double shot” or doppio. (Single shots are normally achieved by splitting a doppio.) If all these factors line up, the barista should be very close to a balanced, well-flavored shot. After this baseline is established, the barista normally tastes their coffee and makes fine-tuned adjustments based on the feedback from their pallet and the look of their shot.
Optimal Appearance and Flavor
Yes, the appearance of the shot is also important. The shot should have a rich, dark color, a thick crema on top, and a smooth, even flow. The crema is the foam that forms on top of the shot and is an indicator of the extraction quality. A thick crema is a sign of a well-extracted shot, while a thin or non-existent crema can indicate an under-extracted or poor-quality shot. The shot should also have a well-balanced flavor with a good balance of acidity and sweetness. A well-extracted shot should have a smooth and rich taste with no bitter or sour notes.
To make a perfect shot of espresso, the barista should pay attention to all of these factors and make adjustments as necessary. This may include adjusting the grind size, the tamping pressure, or the extraction time. The barista should also have a good sense of taste and be able to evaluate the shot to ensure that it is balanced and has the correct flavor profile.
It's also important to mention that a perfect shot of espresso can vary depending on the preferences of the individual, some people may prefer a shot with more sweetness and a milder flavor, while others may prefer a shot with more acidity and a stronger flavor. The barista should be able to adjust the recipe and technique accordingly to suit the individual preferences of the customer.
In addition to pulling great shots for wonderful-tasting espresso, baristas must also consider the quality of the milk used for espresso-based drinks such as lattes and cappuccinos. The milk should be fresh, high-quality, and properly steamed to create a smooth and velvety texture. A good barista can create beautiful latte art designs on top of the milk, adding to the drink's visual appeal.
Espresso Does Not Age Well
Another important consideration is the age of the espresso shot. The shot should be served immediately after it is brewed, this is because as espresso sits, it begins to lose flavor and aroma, and the crema starts to dissipate. To ensure the best taste and quality, the beverage should be consumed as soon as it is brewed.
Cleaning and Proper Maintenance Matters
Great baristas are familiar with the different types of coffee beans and brewing methods, as well as the proper maintenance and cleaning of their equipment. Some professionals deep clean their equipment several times per shift so that older oxidizing residues do not taint the coffee flavors. Baristas also understand the science behind espresso brewing, including the effects of temperature, pressure, and time on the final product.
In a Nutshell
To recap, espresso is a method of brewing coffee that results in a strong and concentrated brew, it was born in Italy and has grown to be a staple in coffee culture worldwide. The beans used for espresso should be of high quality, freshly roasted, and ground specifically for espresso, Arabica beans are considered to be of the highest quality because of their complex flavor profile and higher acidity, while Robusta beans are known for their bold flavor and higher caffeine content.
To make a perfect shot of espresso, the quality of the beans, the ability to finely adjust the grind, the temperature and quality of the water, the calibration and maintenance of the machine, the technique used by the barista, and the individual preferences of you or your customer must be taken into account.
A perfect shot of espresso should have a rich, full-bodied taste with a good balance of sweetness and acidity, a thick and even crema, and a smooth and satisfying finish. It takes a combination of skill, knowledge, and experience to make a truly perfect shot of espresso. And for professionals remember, it’s not only about the coffee but also about the often overall experience, the barista should be able to create a warm and welcoming atmosphere and should be able to interact with the customers in a friendly and professional manner, the cup and saucer that the espresso is served in should be clean and of good quality, and the overall presentation should be visually pleasing.
Sticking to a reliable and repeatable process while keeping a neat and organized station will help professional baristas at the coffee shop pull the perfect shot all day long and get great results daily for the home barista.
So What Espresso Equipment Is Right for You?
Choosing the best espresso setup can be a daunting task, even for those who are knowledgeable about coffee and espresso. There are many factors to consider with each piece of equipment and a wide range of options available on the market.
Do not neglect your budget. There is a solution for everyone on the market, but watching your budget is key because high-end machines and all the accessories can become quite expensive.
When it comes to espresso machines, many manufacturers look to satisfy all types of customers, knowing that some people prefer more manual machines and a hands-on approach, while others prefer the convenience of fully automatic machines. Among those machines, there are many brands, models, features, and options that further complicate the buying process, and we haven’t even gotten to grinders yet.
Grinders might all look alike, but there is actually quite a range of products on the market. There are some crucial considerations when buying a grinder because remember: the grinder is quietly the most important consideration in your setup. A good grinder is the single most effective tool for achieving a consistent and high-quality espresso with balanced flavor and texture. As explained above a burr grinder is essential, but even among burr grinders there are dozens of choices and only some of them will truly serve your needs.
And then there are tampers, portafilters, scales, and timers. Don’t forget you also need room for all of this equipment to fit on your countertop or in a cabinet. With all this sometimes it’s hard to know where to start and what is really important.
But don’t worry, I want to help you!
As an expert with a decade of experience in the coffee service industry, I've poured thousands of drinks as a barista, and have a deep understanding of coffee and equipment. My focus is on training new baristas, and I'm excited to bring my knowledge and experience to help you find the perfect equipment for your espresso setup. Whether you're a home enthusiast or a professional, I will work with you to understand your specific needs and goals and then provide personalized recommendations. Don't settle for mediocre espresso, contact me or another Coffee and Espresso Expert here on Curated and let's get started on your journey to the perfect cup of coffee.