Espresso Preparation Step by Step

The preparation of espresso is influenced by several variables, such as the amount of coffee grounds, grind size, brewing pressure, extraction time and brewing temperature. It's a big advantage for beginners if the future machine setup controls all of these variables. For example, an espresso grinder that is time-controlled and consistently produces the same amount of grounds at the same grind size. The espresso machine should maintain the same brewing pressure at the same temperature and extraction time (shot timer). In my opinion a dual boiler espresso machine and an espresso grinder with automatic dosing are ideal for beginners. If you're sure you rarely or never plan to steam milk, a single boiler with PID is perfectly sufficient.

Digression:
In my opinion, a heat exchanger makes sense if you have experience with espresso preparation, as in this machine design, the brewing temperature can only be indirectly controlled through the heating element in the steam boiler. Additionally, these machines tend to overheat, which makes a "cooling flush" necessary.

When these technical requirements are met, there are two options. First, you teach yourself how to use your machines, which can be quite a lengthy process. Because if you ask 5 supposedly experienced people online, you'll get 533 different opinions. This often leads to frustration and, ultimately, the abandonment of this beautiful hobby. Unfortunately, many insights on the internet cannot be applied to your own machine setup, as each machine, each grinder, each milk jug, and each coffee has its own characteristics. However, in my opinion, the results in the cup are still better than those from an automatic machine, even if you have no idea how to prepare espresso with a portafilter machine.

The second option is training on your own equipment with your own milk and accessories. This method has proven extremely effective for me. Especially since the unique characteristics affect not only the preparation but also the machines themselves. Damage from improper handling can almost be ruled out this way. The machine and grinder are the barista’s instruments, and you need to learn how to play them. If necessary, a thorough briefing from the retailer in the store can help answer initial questions and serve as a guide.

Basic Equipment

• A portafilter espresso machine with the mentioned features.
• An automatic espresso grinder.
• Portafilter baskets.
• A suitable tamper, perhaps even a dynamometric tamper at first.
• A milk frothing pitcher whose volume fits your espresso machine; usually, a pitcher with a total capacity of around 360ml works well.
• Freshly roasted coffee, high quality, at least one week and no more than about three months old from the roast date (rough guideline).
• Milk steaming cloths.
• Barista towel or brush for cleaning the baskets during use.
• Initially, a precision scale with 0.1g accuracy.
• Shot timer to measure extraction time (smartphone, stopwatch, possibly a machine feature).

Before you start, you need to know the fill weight of your current portafilter basket. In our experience, it’s much easier to work with the so-called "double basket" (usually 14g) at first, as the "single basket" is considerably more complicated to handle due to its design. Through my work at the roastery, I’ve come to realize that I can only truly perceive the complexity of a coffee bean once the fill weight reaches at least 17 grams. For medium and dark beans, I work with 18–19 grams for an espresso shot in a standard double basket.

Depending on how strong the coffee is roasted, the weight of the desired fill amount of coffee grounds in the basket will vary. Beans of the same coffee will weigh less in a dark roast than in a light roast, as the specific residual moisture after the longer roasting process is lower.

Initial Step-by-Step Workflow

Making Espresso
• Allow the machine to heat up sufficiently.
• Place the portafilter on a precision scale and tare it (press the "Tare" button to reset the weight to zero). Ideally, start with a double-spout portafilter and the commonly included 14g basket.
• Grind the coffee beans directly into the portafilter, then weigh it again. The coffee grounds should measure between 18–19 grams, give or take, depending on the initial dose.

• Lightly tap the portafilter with the palm of your hand to evenly distribute the coffee grounds (distribution).
• Place the tamper into the portafilter and visually check that the coffee bed is level, then apply firm, even pressure to compact the grounds. If possible, avoid additional leveling afterward, as this can lead to uneven extraction.

• Place the precision scale under the cup and tare it again (press the "Tare" button to reset the weight to zero).
• Lock the portafilter into the group head and start the extraction immediately, as the brew head is hot. If the portafilter with coffee grounds is left in too long before brewing, the heat can "burn" the coffee, negatively affecting its aroma.
• As soon as the pump starts, monitor the extraction time.
• Starting reference point: A brew time of 25–30 seconds, yielding approximately 36g of espresso from 18g of coffee grounds (1:2 brew ratio).

To achieve the desired extraction time, you can adjust two variables: grind size or dose (amount of coffee grounds). However, always change only one variable at a time to clearly understand its effect on the extraction time.
If you adjust the grind size, it may take two to three espresso shots before you see the full effect of the change. This is because residual coffee grounds remain between the burrs and the chute after an adjustment. These leftover grounds are referred to as "retention" or "dead space." Some modern grinders have a retention of as little as 0.1g, depending on their design.

Tip: I recommend identifying a coffee that everyone in your household enjoys and sticking with it for the first six months. This allows you to systematically experiment with changes in brew temperature, grind size, dose, extraction time, and pressure while developing a deeper understanding of how each variable impacts the final result.

Steaming Milk:
• Purge any condensation from the steam wand.
• Steam the milk, creating a smooth, velvety micro foam.

• Clean the steam wand with a cloth, then briefly turn the steam valve back on to expel any remaining milk from inside the steam wand.

• Pour the milk into the cup.
• Done!

The section on “Steaming Milk” will be explained in more detail in future posts.

At first glance, this may seem like a lot, but with a little practice, you’ll become quite fast. This workflow was largely inspired by Barista World Championships and related videos, combined with my own years of experience. This approach works effectively multiple times a day. Once you’ve gained some experience with espresso preparation, you can skip the precision scale or choose to adopt the “Single-Dosing Workflow”, which will also be explained in a future blog post.

About the Author

Hi, I’m Bertram Unrath, born in 1982. My interest in coffee began in 2012 with an old Vibiemme Domobar that had been stored in my parents' basement for 20 years. I restored the machine, and once it was working again, I was curious about how the stuff you make with such a machine would taste. So, I went online, bought a Graef CM700, and got my first coffee beans from a roastery in Mannheim.

Of course, during the restoration process, I registered in the “Kaffee-Netz” forum to get help with espresso preparation. In 2014, I first came into contact with Michael Hauck, the CEO of ECM/Profitec. I was interested in the Profitec Pro300, a machine with potential but hardly described online at the time. From then on, we kept in touch, even if it was just to organize regular “Kaffee-Netz” meetings in Heidelberg.

From early 2013 to mid-2017, I worked part-time in a roastery during my studies because I wanted to experience the journey from raw beans to the finished product. I was also responsible for part of the sales. Among our clients were various branches of an American motorcycle manufacturer, for whose events we were often booked. This allowed me to experience the "preparation of espresso-based drinks" under extreme conditions, depending on how many caffeine-loving bikers wanted an espresso or cappuccino after lunch.

In 2017, I decided to start selling ECM/Profitec coffee machines as a side business. I always picked up my machines in person from Bammental, so naturally, I got to chat with Michael Hauck more often.

Since I believe that this method of espresso preparation is an extremely communicative topic, we always offered our customers training at home on their own machines. The training has a strong practical component and covers topics such as setup, operation, and maintenance/cleaning.
Throughout the entire period from 2012 to 2024, I’ve had many espresso machines and grinders on my coffee bar. I always have at least two machines and four to five grinders from various manufacturers in constant rotation. The bar is 3 meters wide, so there's plenty of space.

True to the motto: “A hobby is the desire to achieve a questionable goal under massive financial expenditure, whose meaning is not or hardly recognizable to outsiders. But it brings joy, and that’s priceless.”
In that spirit: Enjoy reading my posts.