„Forget everything you think you know about coffee – we’re starting from scratch.“ Is this the kind of sentence you want to hear at the start of a coffee-making course? Absolutely! In our coffee special, we bust myths and half-truths about coffee and keep surprising ourselves along the way. So, let’s dive into the highly caffeinated world of beans, grinders and espresso machines!
Behind every great espresso lies a surprising amount of psychology: positive emotions tied to places, moments, and people. “Where did you have the best espresso of your life?“ our barista instructor asks to kick things off. Instantly, we’re transported to magical memories: the cosy familiarity of a local roastery, the bustle of a crowded espresso bar in Rome, or the stylish charm of an Autogrill on an Italian road trip. We’re lost in nostalgic bliss… until Robert snaps us out of it: “That’s all nonsense! Come back to the present. Today is all about pure chemistry and physics. You’re here to learn the know-how.“ Suddenly, it gets serious – we realize the next six hours might completely upend our coffee worldview.
At Rotbart Kaffee near Stuttgart, a blend of industrial charm and cozy kitchen vibes creates the perfect setting for this adventure. The space feels like a playground for at-home baristas: gleaming chrome espresso machines, high-end grinders, and luxurious tools line the counters like treasures. Sanremo, Bentwood, Victoria Arduino, La Marzocco – each name commands respect. We approach the machines with wide eyes and an almost reverent awe, like kids on Christmas morning.
Our group’s experience levels couldn’t be more diverse: from the coffee purist who only uses Volvic water for their espresso, to the Nespresso addict who likes to keep things simple. What unites us? A passion for great coffee, and the desire to stop relying on luck and start brewing top-tier espresso through pure skill. Will we leave the course with any game-changing insights? Excitement fills the air, tinged with a touch of anxiety. We glance at each other, wondering if the breakfast pretzel was enough of a foundation to handle the industrial quantities of coffee we’re about to consume.
Robert Komaritzan shares both the location in Leonberg and a deep passion for coffee with his friend, also named Robert, who runs rb.crafts here. At rb.crafts, coffee machines are customized for clients worldwide – and by the way, you can check out our visit to rb.crafts here. Their work overlaps, as the two Roberts see themselves as a one-stop shop, offering the full spectrum of the coffee universe, from coffee beans to training courses, to customised luxury espresso machines.
This article is part of our Coffee Special, full of product tests, exciting insights and some valuable new perspectives on coffee. Curious? Then click here!
What’s the superlative of sour? And what does that have to do with barista expertise?
Alright, back to reality: Instead of sipping delicious barista espresso, we’re biting into sour citrus fruits. Robert doesn’t mess around – our sensory training starts immediately. We quickly learn that what we think of as taste is mostly about smell. When you say “This tastes like…”, you’re usually wrong. And we’re about to find out why.
With spoons in hand, we’re told to let what’s on them dissolve in our mouths while keeping our noses pinched shut. The result? Nothing. Nada, at least at first. The tip of our tongues barely picks up some sweetness, and the front area a faint hint of sharpness. Turns out, the human tongue can only detect five basic tastes: sweet, sour, salty, bitter, and umami (that savoury flavour we associate with protein-rich foods like meat or soy sauce). Why didn’t we learn this in kindergarten?
Only when we release our noses does the real magic happen. Suddenly, what we’d call “full flavour“ is revealed as a mix of taste and smell working together. Now it’s clear what’s in our mouths: cinnamon sugar. And only now do we “taste“ the cinnamon – oops, we mean smell it. With our noses blocked, we couldn’t detect it at all. Mind blown.
Want to try sensory training at home? Experiment with these natural flavours the same way we did: nose pinched, then released. Start with lemon (sour), lime (sour and juicy), a good Frisian beer (bitter), high-quality dark chocolate (bitter), and grapefruit (sour-bitter). You’ll gradually notice where each taste registers on your tongue: lemon’s acidity hits the sides and fades as quickly as its perfume-like aroma, sweetness is detected at the tip of the tongue, and bitterness lingers at the back of the palate. The same applies to coffee: acidity disappears quickly, but bitterness sticks around.
The DOWNTOWN Espresso Crew: Who joined the barista course?
Did you know? – A few coffee fun facts from the barista pro
- Coffee beans are nothing more than roasted cherry pits, and the coffee cherry is a fruit that, just like the cherries we know, can be plucked straight from the tree and eaten.
- Exclusive varieties like Panama Geisha can cost € 4,000 per kilo or even more, as they are of top quality and available only in limited quantities. Geisha is particularly popular in Japan’s coffee scene. That makes sense: the Japanese, known for seeking the essence of tea and combining tradition with perfection, don’t lower their standards when it comes to coffee either.
- Why has a glass of water with espresso been an Italian tradition for over a hundred years? Because clean water and good plumbing were not a given back in the day, Italian cafés in the early 20th century served a glass of water with espresso as a mark of quality – to show that the coffee was made with clean water. And here we thought it was simply about staying hydrated!
- There’s quite a bit of marketing and image involved: with espresso machines, maintaining a consistent temperature is one of the core features. According to Robert, machines costing € 3,000 can often achieve this just as well as those priced at € 13,000.
- The best brushes for cleaning your portafilter? You won’t find them at coffee accessory shops but at the hardware store – in the professional painter’s section, of course!
Caffeine marathon and taste buds put to the test
Now it’s time to experiment. Spread across two long workstations, each of us faces our own setup: machine, grinder, scale, dosing cup, tamper, distribution tool, and even a little brush for clearing coffee grounds. Robert has pre-set all the grinders, but isn’t giving away any details. All he shares is this: our first espresso is going to taste awful.
Today, we’re working with the common 1:2 ratio, meaning we’ll extract double the amount of liquid compared to the amount of coffee grounds. For a doppio, we’re measuring out 19 grams of finely ground coffee and aiming for 38 ml of espresso from the portafilter. Precision is still a challenge, and the espresso pours a bit too quickly from the spout.
Still, we feel a tiny bit like pros as we swirl and stir our first coffee to mix the crema with the liquid beneath. Another lesson learned: the crema contains many of the bitter compounds, which settle on top as the espresso brews.
But that first sip quickly brings us back to earth: yuck! Completely undrinkable. We’d spit it out if we could. The acidity dominates, hitting the sides of our tongues hard. “Don’t let it throw you off,“ Robert says with a mischievous grin. “Keep experimenting and gradually adjust the grind finer.“
And sure enough, something changes. With every tweak of the grind, the perceived flavour of the beans shifts. It starts at the front and sides of the tongue and gradually moves to the back palate, until we finally end up with a distinctly bitter espresso instead of a sour one. Lesson learned: grind size is everything! By deliberately starting with an overly coarse grind, our instructor made it clear – even to the least sensitive among us – which is the most important variable in coffee preparation. According to Robert, the grinder determines 40% of coffee quality. It makes sense, though. When every tenth of a gram of coffee grounds affects the outcome, a precise and consistent grinder becomes essential. Some grinders, however, struggle with fine settings, especially for light roasts. Breaking down the harder bean structure to achieve a balanced flavour requires a finer grind. Robert’s pro tip: if your grinder can’t handle super fine settings, stick to darker roasts. They work well with slightly coarser grinds and still taste fantastic. Noted!
Phew! Ever had 10 espressos in an hour? You can definitely tell who had a solid breakfast and who didn’t. By now, we’ve tasted the full spectrum of flavours hidden in our “workhorse bean“ – at least as much as our amateur palates allow – and we’re ready for some fine-tuning. Some of us are looking a bit pale, but no one wants to give up before reaching the finish line: that magical moment when sweetness, acidity, and bitterness dance in perfect harmony on the palate. When we finally nail it at the end of the experiment, we’re left as a shaky, jittery pack of zombies, barely able to string together a coherent sentence – but hey, we’ve pulled an excellent shot of espresso from the machine!
The 4 grand players in coffee brewing
Check: Grind size has a massive impact on sweetness, acidity, bitterness, and the development of aromas. But what other factors determine whether espresso is a delight or a disappointment? Robert’s take on the importance of water delivers a serious wake-up call to our previous assumptions: in his experience, water accounts for a whopping 30–40% of the flavour – more than the machine! Hardness and mineral content play a key role. His tip: for optimal aroma, use soft water. Not only does it protect the machine by reducing limescale build-up, but it also enhances the espresso’s flavours – win-win! Many coffee aficionados install water filters directly into their plumbing, but even a simple filter jug can make a huge difference for casual users. For an easy option, bottled water works great: brands like Volvic or Black Forest are especially favored by baristas for their ideal mineral composition.
Among the four key players in crafting the perfect espresso is, of course, the machine. Surprisingly, it plays a much smaller role than we initially thought. According to Robert, it accounts for just 10–20% of espresso quality. Naturally, it must deliver consistent temperatures reliably and not take an eternity to heat up. And since different beans require different temperatures, it’s a bonus if the machine allows water temperature adjustments. However, the lion’s share of the result – at least according to Robert – comes down to the grinder and the water. Crazy, considering the common perception of machine quality and the claims of self-styled coffee connoisseurs.
The fourth player on the team is the barista, who also contributes 10–20% to the potential for a great coffee. And the bean? It’s in a league of its own, because nothing happens without it. It sets the limits or opens up infinite possibilities for the most complex flavour experiences. With supermarket coffee from monoculture mass production, no one will find happiness – at least not if they care about quality. To get the most out of premium beans, Robert advises storing them in airtight containers and using them quickly because:
The greatest enemy of good coffee is the human. The second greatest is oxidation.
Spoiler: Coffee roasters truly understand the significance of high-quality beans. For our DOWNTOWN Coffee Special, we visited BlackBird Coffee roastery and gained valuable insights into selecting the perfect beans. More on that shortly.
Our world turned upside down – Where we’ve been wrong all along
In Our DOWNTOWN Coffee Special, we’re busting myths and half-truths. We’re on a mission to debunk the coffee myths that swirl through the world of the “brown gold.“ Sure, it can sting a little, realizing you’ve been spouting misguided coffee wisdom for years, but it’s part of the process. By the end of the barista course, our heads were spinning – not just from the caffeine, but from all the new insights we now need to digest. Here are a few eye-openers:
- “Espresso beans“ are only for espresso?
Nope, we fell for the marketing hype. In reality, these are darker, hotter-roasted beans that work just as well for filter coffee or a French press. The key difference? The grind: finer for espresso, coarser for filter coffee and presses. As for taste, darker roasts often mean more bitterness – but flavour preference is entirely subjective. - Ignoring grinder retention? A rookie mistake.
Here’s the bitter truth: many of us drink subpar espresso daily because we overlook the stale grounds left in the grinder. This residual coffee turns your first shot into an aroma disaster. The pro tip? Run a few grams through the grinder and toss them. It hurts, but quality comes at a price. - Preheating cups is a must? Not always.
Coffee nerds warn against it: excessive heat can cause aromas to evaporate. For the full flavour spectrum, let your coffee cool to about 40°C before drinking. Nerdy? Absolutely. Eye-opening? Without a doubt. - Open coffee beans in the fridge? Big no-no!
Moisture invites mould, and leaky packaging lets beans soak up fridge odors – from cheese to half-eaten bell peppers. Instead, store beans in the freezer. They’ll stay fresh, and you can thaw small portions as needed. - Fancy paper packaging = sustainable coffee?
Unfortunately not. While the coffee might be sustainably sourced, composite materials combining paper and plastic are worse for the environment than plain plastic, which is easier to recycle. Our takeaway: sustainability isn’t about looks.
My grinder, my machine, and me: insights for the perfect home setup
Are we heading home much wiser after our coffee lab adventure? Absolutely. After our barista course, we feel far more confident and now know exactly what to adjust in our own setup to get closer to our idea of the perfect espresso
Water quality first
Filtered water or still mineral water like Volvic or Black Forest are now at the top of our shopping list. We’re excited to experiment and discover which water truly elevates our favorite espresso.
Choose your beans wisely
For less powerful grinders, it is better to use darker roasted beans. Due to their higher degree of roasting, they do not require an ultra-fine grind and are easier to process.
Buying a machine with focus
For our next espresso machine purchase, we’ll focus on temperature consistency. The more evenly a machine maintains temperature during and between shots, the better it is for brewing great espresso.
Of course, we wanted to know Robert’s recommendation for the perfect machine and grinder combo. But since it really depends on your use case and budget, this question isn’t easy to answer. However, here’s a tip for anyone looking to create a solid setup without breaking the bank: For around € 200, the De’Longhi EC 885 offers fairly consistent temperature control (its plastic casing means less material to heat for the brewing process). Pair it with the single-dosing VS3 grinder from Varia, priced at about € 370, and add some barista tools from JoeFrex or other brands to elevate it. For roughly € 600, you’ll have a setup that delivers excellent espresso.
Three hours that turn 20 years of amateur coffee experience upside down. And it’s not just the caffeine overdose making our heads spin after the barista course. What we learned during those hours stirred up our coffee world as thoroughly as a spoon mixes espresso in the cup. But we can tell you all about it – what really matters is trying it for yourself and tasting the difference. The world of sensory science, beans, and grinders is full of secrets. So, what are you waiting for?
You can book latte art sessions, fully automatic machine courses, and barista classes at Rotbart Kaffee for the Leonberg and Stuttgart-Fellbach locations here.
Words: Felicia Nastal, Susanne Feddersen Photos: Jan Richter, Peter Walker
