Prepare espresso like an expert

If you love enjoying a delicious espresso, latte, or café con leche at your favorite coffee shop, but would love to enjoy equally delicious coffee at home, this post is for you!

Kim Osenblock and Danilo Lodi are coffee ambassadors for the Italian espresso machine manufacturer Dalla Corte. They agreed to give me tips on how to make espresso at home as a barista. Making a good cup of espresso isn't as difficult as it seems. With the right equipment and a little know-how, you'll be taking amazing photos in your kitchen in no time.

Understanding Espresso

Before we delve into its secrets, let's first understand what espresso actually is.

This short coffee is characterized by its strength, thanks to its small volume and low pressure during preparation. According to the Specialty Coffee Association (SCA), "Espresso is a 25 to 35 ml serving of coffee made with 7 to 9 grams of ground coffee, prepared with water at a temperature of 90.5 to 96.1 °C (190 to 200 °F) with a coffee pressure of 9 to 100 atmospheres." It is ground into a powder so that the extraction time is between 20 and 30 seconds.

These 20-30 seconds are a good timeframe. However, it's worth remembering that there are no specific rules for setting this time. The coffee's performance during extraction depends on many factors, including grind size, coffee origin, roast profile, your personal preferences, and more. So, let's take a look at some expert tips on how to improve your home espresso.

Start with quality coffee

Good coffee starts with quality beans. "First... a cup of specialty coffee," Kim told me. "We can say that fresh, freshly roasted coffee has more chocolate, red fruit, and caramel flavors... and the acidity should be a little lower, because the acidity of espresso always increases."

The characteristics of the coffee roast are also important. Coffee roasted too dark will have a bitter taste, while coffee roasted too light will have an overly sour taste and lack sweetness and balance.

"I think the line is between dark brown and dark tan," suggests King. He also recommends a medium roast, specifically made for espresso. "I always recommend... asking the roaster where you want to buy: 'What espresso would you recommend?'"

As Kim said, the roasting date is also important. Coffee is a biological product: it deteriorates over time. However, there is also the possibility of it being "too fresh," especially with espresso. Coffee must be degassed in this way to remove the completely harmless carbon dioxide that forms during the roasting process. Initially, coffee degasses quickly, which impairs the extraction of flavor and aroma compounds. However, if the coffee is decarbonated too much, the flavor will be reduced and it will be difficult to obtain a crema.

Additionally, it's best to buy coffee beans that haven't been exposed to oxygen, sunlight, or excessive heat (or temperature changes). The only exception to this rule is if you're using a low-quality grinder.
Danilo recommends buying only a small amount of coffee at a time, which makes it easier to preserve its freshness. "If the coffee bag is resealable, squeeze out the air by crushing it and keep it away from light, heat, and moisture," he adds.

Use high-quality equipment

Good equipment doesn't always guarantee a good espresso, but it can make it easier. The two most important things you need are a grinder and an espresso machine.

“The grinder will determine how much coffee you can get from a cup,” says Danilo. “You want the grind size to be between coarse and fine to be able to use it.” This way, you can adapt to each coffee and get the most out of it.
Kim recommends investing in a flat knife sharpener. Not only is it faster, she told me, but it also provides a more uniform grind size.

Espresso machine

"You have to focus on the stability of the water pressure, temperature, and volume. The appliance should deliver the same results with the first cup of coffee as it does with each subsequent one," advises Danilo.

Don't forget to ask about the kettle. Kim remembers buying her first Dalla Corte Mini coffee machine when she started in the coffee business. She told me that one of the reasons she bought this coffee maker was because it had a separate carafe for the coffee head. She wanted to practice the art of latte art and knew that a separate boiler would allow her to use steam without affecting the stability of the machine or the consistency of the espresso.

When shopping for an espresso machine, Kim considers many of the same things as Danilo, but she also believes it's important to be able to control the variables. "What else should I look for...?" "You can adjust the temperature, pressure, flow, etc., or you can play around with it a bit so you can play with more parameters." Of course, ease of use is also worth considering. While it's great to have a device that gives you full control, it's useless if you don't know how to use all the functions. Home espresso machines, like the upcoming Dalla Corte Studio, come with a control panel that allows you to adjust the temperature, dose, pre-infusion, and more.

Oh, and don't forget how important maintenance is. Danilo recommends cleaning the machine after every use. "This will help your equipment run smoothly for years to come," he said. Also, he says, if you're not using a kettle to generate steam, it's best to change the water at least every two weeks.

Grind the coffee correctly

Remember when we said that degassing can result in stale coffee? Well, degassing accelerates dramatically after the coffee is ground. The fresher the grind, the fresher the flavor. This is why whole bean coffee is generally better.

Also, when preparing to grind the beans, you should consider the grind size. This is important because it affects the extraction rate of the aromatic and flavor compounds present in the coffee. The finer the grind, the faster the extraction.

Controlling the degree of extraction is essential for obtaining good-tasting coffee. This is because the first compounds extracted create fruity and acidic flavors; then, the compounds responsible for sweetness are extracted; and finally, we obtain bitterness and astringency. When preparing coffee, the goal is to obtain a balanced cup, with great sweetness and a reasonable amount of acidity and bitterness.

At the same time, the grind size affects how quickly the water passes through the coffee, or, in other words, how long it takes to extract a shot of espresso. If the grind is too fine, it acquires a consistency similar to wet sand and takes much longer for the water to pass through. Consequently, this increases brewing time and, therefore, the degree of extraction.

Kim told me, “The grind needs to be fine enough so that your coffee comes out in about 20 to 30 seconds. So, if…you have a grinder that doesn’t grind fine enough, your espresso will always come out faster. And by coming out faster, you don’t get to extract the sweetness out of the coffee and you’re left with more acidic and salty flavors.”

“When you manage to extract the coffee for between 20 and 30 seconds…[you manage], apart from those acidic and salty flavors, …to contribute the sweetness of the coffee itself.”

In other words, grind size is critical if you want a delicious espresso . The coarser the grind, the faster the extraction, and you'll experience less bitterness and more acidity in the cup. The finer the grind, the slower the extraction, resulting in more bitterness and less acidity.

Due to the short extraction time, preparing espresso always requires a fine grind. However, if your espresso doesn't taste the way you'd like, you can adjust the grind setting and see if this solves your problem.

Establish the relationship between coffee and water

How much water should you use? Well, it depends on how strong you want your coffee. Kim recommends starting with a 1:3 ratio. For every gram of dry coffee, you should get 3 ml of espresso in your cup.

However, you can also experiment with different recipes based on your preferences. Try a 1:2 ratio for a stronger coffee, or if you want something more lungo -like , try a 1:4 or even a 1:5 ratio.

Remember, there is no “best recipe”: there will always be one that best suits each coffee and your taste.

But no matter which recipe you choose, it's best if you measure the coffee and water with a scale. You've seen many specialty baristas weigh both the grounds and the shot they've extracted. This allows them to use the exact right ratio to ensure the same delicious coffee every time. And it's also an easy process for baristas to follow.

Pay attention to the temperature and quality of the water

It's not just about how much water you use, but also the type of water.

Poor-quality water can damage your equipment. Hard water, in particular, can create limescale buildup that could affect your machine's performance.

Additionally, water quality can also affect the flavor of your coffee. If your tap water is chlorinated, you may end up with a bland espresso . Water that's too hard can result in bland brews. On the other hand, soft water can make your coffee flat or lack body.

Kim recommends using water with a neutral pH and a total mineral content of between 100 and 150 milligrams per liter. “[It's best] to use bottled water or use [water] that's been filtered with an activated carbon system,” Kim said. “There are several brands, for home use as well; an activated carbon system for the tap [is] good.”

You can also experiment with water temperature to affect your extraction: the warmer the water, the faster the aromas will be extracted. However, Kim suggests keeping it between 90 and 93ºC/194–199ºF.

“A couple of degrees higher or lower can change the flavor,” Kim said. “So, it’s important to have temperature stability.”

Distributes and tamps coffee evenly

Finally, you're ready to extract your espresso shot. But before you begin, consider this: what happens if your coffee isn't evenly distributed in the portafilter? The answer is simple: bad coffee.

Obtaining good-tasting coffee depends on whether the different ground coffee particles have the same degree of extraction (or as similar as possible). However, if some particles are more compact in one section of the portafilter than in another, the water will pass through the path of least resistance and flow through the coffee with a greater amount of air. These particles will be over-extracted, while the others will be under-extracted due to less exposure to water.

So, before tamping, make sure the grounds are evenly distributed. If you grind coffee directly into the portafilter, you can move it around a bit while dosing to ensure this uniformity. There are also many techniques and tools you can try.

Once your coffee is evenly distributed, you can tamp it. Danilo told me, “We must tamp the coffee evenly and consistently to extract the flavors and sugars into the cup. Even if you prepare it at home, you must do it to get a great result.”

“You don’t need to [apply too much pressure],” Kim advises. “[You want to pack] enough so that the water encounters the same resistance throughout the coffee.”

And now, finally, after grinding the coffee, setting the ratio, and tamping, you're ready to extract a fantastic shot of espresso. Enjoy!

Translated by: María José Parra.

Please note: This article was sponsored by Dalla Corte.

Post credits: PDG Español.

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