It is 20 years ago when inventor and coffee lover (not a barista) Alan Adler developed the aeropress. His quest was simply to make a better cup of a coffee, more consistently and somewhat quicker…
Today, millions of aeropress coffee makers travel everywhere we go and bring us a tasty, quick, solid cup of coffee. From Arizona canyons, to camp sites in the South of France, to the plains of Eastern Europe, back country of Australia and ocean islands in the Pacific. It is ubiquitous and still going strong!
What used to a single product is branched out into a wider variety of choices, materials and add-ons.
Aeropress Original
Aeropress Premium
Aeropress Clear
Aeropress XL
Aeropress Go & Go Plus
Very recently, Aeropress have also introduced a manual grinder to match their style and create the option to get everything from one source. Very smart, though it may not be the best manual grinder for your money. That remains to be seen…
I have always wondered how my coffee brew gets its zing. What makes up that “Golden Cup” of coffee? Why is one cup extraordinarily great and the next good but not quite that good, even though you used the same beans, same grinder, same water, same brew method?
The art of being a good barista is that you’re able to make a great coffee every single time. Turns out it’s not just about coffee beans and water, it’s actually a whole chemistry lab in your cup! 🧪
Five years ago, the Simonelli Group reached out to the Coffee Science Foundation, asking if they could somehow work together on cutting-edge espresso research? That open question in 2019 led to the start of an exciting multi-year research project by Professor Christopher Hendon at the University of Oregon, that wants to measure the chemistry that goes on in your cup of espresso.
That initial conversation led to a truly exciting initiative—a multi-year research project aimed at measuring espresso chemistry, correlating those measurements to sensory attributes, and laying the groundwork for science-based useable tools for the coffee industry.
Long story short: scientists are using electricity to break down what’s in your espresso. How do chemical compounds affect the taste of the cup of coffee and the flavors that you experience? 🤯
We all know coffee can taste amazing, but it can also be a rollercoaster of flavors. Is it the beans, the roast, the water, or your barista skills? 🤔 Turns out, it’s all of these things, plus a bunch of tiny molecules we’re just starting to understand.
Traditionally, we’ve always measured coffee strength using TDS (Total Dissolved Solids) – basically, how much coffee stuff is dissolved in the water. Coffee is still 98-99% water. But here’s the thing: you can have two cups with the same TDS that taste totally different. 🤯 That’s because TDS doesn’t tell us what kind of stuff is dissolved, just how much.
This is where electrochemistry comes in. It’s like using a tiny electric probe to see what molecules are in your coffee and how many of them there are. Different molecules react to electricity in different ways, so we can use this characteristic to create a kind of “fingerprint” of your brew.
This is super cool for a few reasons. First, it can help us understand how things like roast level, brewing time, and even the type of beans affect the flavor. 🔬 Second, it could lead to new tools for baristas to dial in their espresso perfectly every time. 🤩
The research is still ongoing, but the possibilities are endless. Imagine being able to measure the exact chemical makeup of your coffee and adjust your recipe to create the ultimate flavor experience. 🤤
So, next time you’re sipping your latte, remember: there’s a whole world of science behind that deliciousness. And who knows, maybe one day you’ll be using electrochemistry to brew the perfect cup! ☕️😎
Source: Amped Up: Using Electricity to Detect and Quantify Molecules in Brewed Coffee | 25, Issue 18
A site called LabDownUnder has a blog about research from Australia that explores using ultrasound to brew coffee. In other words, the high-pitched sound waves used in medical imaging can also make a cup of coffee!
They wanted to see if ultrasound could change how much of the good substances (such as caffeine, oils, and flavors) gets extracted from the coffee grounds.
Coffee Sonication
To test this, they brewed filter coffee with and without ultrasound, changing things such as how much coffee they used, the water temperature, and how long they used the ultrasound. They then measured the concentrations or quantities of antioxidants, caffeine or oils, and the specific smells and flavors in the brewed coffee. They also judged what the coffee looked like – its color and how much foam it made.
Ultrasound can be used to extract important compounds in the brewing process through what is known as cavitation. As the sound waves travel through the water surrounding the grounds, differences in pressure create microscopic bubbles which themselves expand and collapse.
LabDownUnder
The Findings
They found that ultrasound helped get more caffeine and oils out of the coffee grounds. This is probably because the ultrasound waves shake things up at ultra fast rates, making it easier for the compounds in coffee to dissolve into the water. They also found that ultrasound helped extract more of the compounds that give coffee its aroma, which means the coffee might smell even better!
However, they noticed that ultrasound seemed to decrease the amount of antioxidants in the coffee, especially when they used it for longer or at higher temperatures. Also, the coffee brewed with ultrasound had a lighter color and less foam, which they think is because of the extra oils. These oils are called triglycerides.
While traditionally the crema floats on top of the coffee, ultrasound actually emulsifies the triglycerides (oils) that make up the crema layer with the beverage, mixing them together. This created a milky-looking beverage with caramel tones.
The Results
Overall, the research suggests that using ultrasound to brew coffee could be a way to make coffee with more caffeine, a richer flavor, and a stronger aroma. However, it might also have less antioxidants and a slightly different appearance. More research is needed to fully understand the potential of ultrasound in coffee brewing.
Dr Francisco Trujillo of the School of Chemical Engineering of UNSW was chief investigator behind the study. The original article has a link to a video made by the researchers, that I cannot link to without permissions. They also show a photo with a color comparison between French press and sonicated coffee. The sonicated coffee looks like it already has milk added to it, when it doesn’t! Check the link to the blog at the top.
For those who love both coffee and adventure, cold brew coffee is a game-changer. It’s not just about the delightful aroma that fills your car, but the complex flavor profile that unfolds over time as you are driving and keep enjoying that wonderful flavor. Unlike traditional coffee, cold brew boasts a smoother, less acidic taste with a lingering finish that keeps you invigorated throughout your journey.
The cold brew method extracts flavor from beans using only cold water (< 20 C/70 F) and a very long brew time. This way, most of the harsh bitters and oils in roasted coffee are not dissolved which results in a coffee with a softer balance of flavors.
Unleashing the Magic of Sumatra: Indonesia Sumatra Organic
The key to an exceptional cold brew lies in the bean selection. I highly recommend the Indonesia Sumatra Organic beans from Boot Koffie, but you can also find these at Whole Foods and in various online shops. These beans, grown in the rich, volcanic soil of Sumatra in Indonesia, yield a full-bodied, medium-dark roast with a distinct chocolatey undertone and subtle spice notes. This unique character sets them apart from the milder Colombian varieties.
Crafting the Perfect Cold Brew
Achieving the perfect cold brew is an art form and highly subjected to your personal tastes. Here’s my preferred recipe:
Ingredients:
67.5 grams coarsely ground Indonesia Sumatra Organic coffee beans
750 ml filtered water
Brewing Process:
Combine the ground coffee and water in a container. (5-10 min)
Steep in the refrigerator for 12-24 hours.
Filter through a fine-mesh sieve or cheesecloth. (5 min)
Savor your expertly crafted cold brew.
While 12 hours yields a flavorful brew, the full spectrum of flavors (particularly the chocolate notes) emerge after a 24-hour steep. Depending on your personal style, you can vary the brew time accordingly. If you like it, that was a good recipe!
A Word of Caution: The Caffeine Kick
Cold brew coffee is known for its potency, packing upto 2-3 times as much caffeine as an espresso or drip coffee. Opt for smaller servings to enjoy its benefits without overdoing it.
Also consider the beans you are using: Robusta beans have 2x the caffeine of Arabica beans! Cold brew is ideally suited for Robusta beans, in my opinion, because the lack of heat means you don’t extract as much of the bitters.
For convenience, I recommend the small, glass, reusable sample bottles available at identipack.com, for instance. Mine serve 50-60ml of coffee.
They’re perfect for pre-portioned servings, allowing you to enjoy your cold brew on the go. As a bonus, you can conveniently open a bottle by yourself, while everyone else in the car is sleeping p[eacefully!
In Conclusion
Cold brew coffee elevates your travel experience. Its alluring aroma, complex flavor profile, and sustained energy boost make it the ideal companion for those on the move. Explore the world of cold brew with the Indonesia Sumatra Organic beans and discover a new level of coffee enjoyment.
Equipment & Gallery
Below you can see a set of photos of how I prepared my cold brew. The brewer I use is the simple, elegant but great Hario Filter-In-Coffee bottle, available everywhere for approx 30-40 Euros. There is a larger version, but be careful: it holds so much cold brew you will need to notify your physician of what you are doing! (A joke, do not drink a liter of cold brew!)
I get asked this question a lot: “What’s the best coffee machine for at home?” Just like: “What’s the best coffee to buy?”
I understand why people ask it, though. They want an experienced opinion. I’ve tasted more coffees than most. Unfortunately, it is not that easy.
To answer the question: “What is the best coffee machine to use at home?”, I would first need to know what kind of coffee you prefer? In other words, the drink itself:
Black or milk-based coffee?
Espresso or filter coffee?
Drip, pour-over or submersion coffee?
To choose the best coffee machine for making coffee at home, you need to find your favorite style next. Then find the best machine that suits that style. That said, I can give a couple of recommendations for good coffee machines for your home. These machines make a great cup of coffee every single day.
Most people either prefer espresso-based coffee or filter coffee. We have all grown up to become accustomed to dark roasted, fairly bitter tasting coffee (with or without milk). With that in mind…
Espresso machines
When buying any espresso machine, do pay attention to the diameter of the portafilter. It is a handle-like device that holds the coffee grounds and attaches to the espresso machine’s brewing group. The portafilter plays a crucial role in the extraction process, determining the flavor, strength, and quality of the espresso shot.
Ensure that this is 53 – 58 mm, which are the industry standards. It should hold 14 – 24 gr of ground coffee. Anything smaller will also work but it will be much harder to find parts, accessories and additional tools. And you will get more tools! LOL
Fully automatic
Don’t get a fully automatic machine! Ever! Seriously.
My biggest complaint about fully automatic espresso machines is that they grind the beans for you without any useful form of manual adjustments. The manufacturer will never include a great grinder. That would make the machine too expensive. Always get a separate grinder, it will last you at least 10 years.
These automatic machines focus on convenience, speed and not flavor. So in my opinion, this is always a setback that I can’t except.
If you prefer speed and ease over flavor, then choose either of these:
The Pro version lets you tamp the coffee yourself. The Impress version has a built-in tamper and will do it for you. ¯\_(ツ)_/¯ Since tamping affects taste much, I prefer to do it myself.
I personally don’t like a Jura machine. Although it’s pretty, it’s too limited and maintenance is expensive. Sorry Jura.
Semi automatic
These machines are more my style. They automate some of the actions but not all. This gives you more control over the espresso that’s brewed. Note that a great espresso maker will cost at least 1250-1500 Euro/Dollars because of the quality of the parts and build. That does not include a grinder!
Your biggest choice depends on how you drink your coffee: black or white?
If you prefer black coffee (an espresso, long black or americano), your life is easy: choose a single boiler machine. They’re a lot cheaper.
Do you (or your partner) prefer white coffees? Think about how many cappuccinos or lattes you will make? For one or two each time, it’s fine to get a single boiler machines as well. First froth your milk then brew the espressos! If you drink more coffee daily or host regular dinner parties, then you should opt for a dual boiler machine. That way, you can start frothing the milk while the espressos are still brewing.
La Pavoni Stradivari
Manual espresso machines
A category on their own for this is where innovation really shines.
Superkop is a brand new, solid, durable design and fully non-electrified. It will work when the power is out, on the road or camping, when disaster strikes and zombies invade our homes! It only needs hot water and ground coffee. It will last a lifetime with only a few replaceable moving parts.
The lever-operated La Pavoni is a classic machine! A gorgeous design that does require some practice and getting used to. Once you do, it is the holy grail of many baristas. Beautiful to look at and room for creativity to add you own special twists when making an espresso.
The Flair revolutionized the world of home baristas when it appeared on Kickstarter. It’s cheap, easy to make, easy to use and a great way to get into making better coffee at home. Quality has improved a lot since and you can’t go wrong with it!
Filter coffee machines
Moccamaster KGB Select
The traditional home coffee makers have received a ton of innovations and improvements over the last 3-5 years. Coffee making, filter coffee at home, has drastically improved since the 80s and 90s. Designer machines, premium options, gorgeous materials and very reliable manufacturing mean that today’s coffee maker is light years ahead of those our parents and grandparents used.
Moccamaster has been the go-to coffee maker for many official coffee competitions and conferences. They’ve been around for 40 years and are rock solid, well built and easy to maintain or repair.
You can also refer to the SCA certified list of approved coffee makers. The Specialty Coffee Association takes their work very seriously. Every machine is thoroughly tested and retested to ensure it makes a great cup every single time, all the time.
I hope this answered some of your questions and gave you a good start to selecting the best coffee machine for your home. Maybe it just confused you more and made you reevaluate what it is you want. Then at least I did my job. Trust me when I say that you will not find the best machine in one go. I will take several iterations before you find what works best.
Most of all, your taste for coffee will change and that brings new machines, new coffees, new equipment and new kitchen setups. If you can, buy second hand on Ebay or your local penny savers. Closed restaurants often sell off their equipment to pay debts. That’s a nice way to get a premium machine for less.
PS: If you follow my advice above and do not buy a fully automatic machine, you will need to also buy a good grinder. That’s a whole new subject, but for starters I can recommend watching James Hoffman’s review video:
This year I can finally participate in something that’s been a dream of mine since I started working with coffee in 2017 and getting certified by the SCA… Corona has been forcing the competition to be postponed. I was going to first volunteer and help others participate, but I’ve decided to just dive in.
At the preliminary, you have to brew 3 cups of an unknown coffee bean in 15 minutes using your preferred brew method. You receive the beans on the day of your round and you get 30 minutes in advance to determine your best recipe using the beans provided, water present and a grinder to use.
Time lapse of a practice run
The preliminary is held at Alleborgh coffee in Almere, a well known espresso machine dealer, who has a backoffice practice floor where you can setup. They’ve been cooperating with SCA Nederland forever, as far as I know.
Not knowing the water used and using a guest grinder is an extra complication. Baristas know their own equipment in and out and can fine-tune results often instantly to compensate for dinner ad-hoc deviation
I’m going to double check the requirements again before Tuesday Feb 22nd, when I’m scheduled to go on stage, but I believe you get 15 minutes total time and can use 8 minutes to set up and 7 minutes to produce 3 cups of 180 grams of coffee liquid.
I also learned that you’ll get 15 min additional time familiarize yourself with the grinder (a mahlkonig EK43 🥰) and can bring your own coffee to achieve the grind size you’re set on using. There are tools to help with this task, such as a Kruve sieve or a ruler that indicates particle size, but I don’t have those yet. Maybe if I make the finals…
This is not that hard at all but the complexity increases because you kinda have to brew 3 batches of coffee in parallel and start the 2nd while you’re still brewing the first. This is where timing gets tricky and routine is crucial!
The coffees are judged blindly (they do not know who’s coffee they judge) on flavors, taste and consistency by a professional jury who’ve sampled the same coffee for themselves, so they know what’s possible to achieve. In a way, it’s whoever is closest to what they achieved wins.
One of the better things that Corona has brought to the world is the increasing availability of fantastic, fresh roasted, coffee bean subscriptions to all those who value excellent coffee when working from home! There are so many coffee roasters that have popped up as well and they sometimes bring you true gems from the coffee world to your home.
Fresh roasted beans
A coffee subscription brings you freshly roasted coffee beans to your doorstep on a regular basis. Some let you choose the frequency at which this happens, others deliver it to you every other week or month. Often, you can choose the “profile” of the coffee, which means you can decide if you want to the coffee roasted for espresso (a little darker) or for filter (a little lighter).
Did you know that coffee loses most of its delicate flavors within 15 minutes (!) after grinding? If you have always used supermarket coffee, then you really do not know how good coffee can taste!
Most coffee subscriptions can send you a fixed set of beans of your choosing, sent to you at regular intervals. You chose the roast level (espresso or filter, dark/medium/light), the quantity and which beans. From then on, you’ll never run out of fresh coffee beans again.
You may be able to set some parameters, such as blend vs. single origin or washed vs. natural beans. A few promise to occasionally send you a surprise coffee or a special coffee as well, as a thank you for your loyalty. This means you get a reliable source of great coffee beans sent to your house.
Quality of the beans
The quality level is above and beyond what you can get from the supermarket or your local coffee store, despite the latter already offering a much better bean than the supermarket. Local coffee roasters simply chose better green beans and take more pride in their (artisan) craft. They take more time and care to roast the beans slowly, which greatly enhances the flavors in the beans (source).
A rotating coffee subscription is a subscription for fresh coffee (beans or ground to your specs) that arrives regularly, but contains different coffees each time.
No Pressure Coffee
Another benefit of getting a fixed set of beans on a rotating schedule is that you don’t need to complete redial your brew settings all over again. Each bean often has a unique recipe: the setting on the grinder, the weight of dry coffee you use for the best flavor, the temperature of the water used to brew the coffee and maybe even the number of pours used to make filter coffee. If you write down your recipe (I highly recommend you do!) then when you get a known coffee again, you can simply reach for your last recipe and use that instead of having to go through several runs to optimize the recipe for taste.
Rotating subscriptions
Some coffee subscriptions give you the option to rotate the beans regularly. Each new delivery will bring different beans than the one before. I call this a “rotating subscription“. It’s a lot of work to source new green coffee beans on a regular basis, roast them and taste/cup them, adjust roasting profile, weigh and package all the subscriptions and do it all over again a week (or so) later. That’s something that only a handful people manage.
But… if you stay on long enough, you may start seeing certain beans reoccur. Not everyone has a limitless supply of every bean out there. Even roasters buy limited quantities of green beans and these run out, eventually.
Recommended Coffee Subscriptions
Here is my list of recommended coffee subscriptions in the Netherlands:
NOTE: all of the above roasters now offer a choice between a fixed or a rotating coffee subscription! That’s great news for us.
the coffee vine, Amsterdam (2012), is a unique coffee subscription because they use rotating coffee roasters and ship their monthly changing beans all across Europe and world-wide! They have true gems and unique beans but the coffee is not what I’d call suitable for beginners. If you’d like to try totally different and wonderful beans each and every time, this is your go-to place!
If you are a coffee roaster and you offer a (rotating) coffee subscription as well, please get in touch with me if you’d like to be included in this list!
No Pressure Coffee
Update Jan 2024: Boon no longer exists, filter box by Man met Bril is gone, Black and Bloom has sadly reduced their catalog and does not serve a subscription anymore, Uncommon added. Text updated and reworded.
The Coffee Science Education Centre (CSEC) in Australia tested the impact of a range of tap, artificially modified, and purified waters on the flavors of coffee in an espresso. The chemistry of the resulting brews and brew waters was analysed scientifically through gas chromatography with mass spectrometry, inductively coupled plasma optical emission spectrometry, a bank of photometers, and a series of pH/conductivity multi probes.
What a brilliant idea! I have long asserted certain differences in the flavors in a cup of coffee to the water used, but never really thought about it scientifically. Sometimes my favorite coffee tasted completely different when brewed at a friend’s home. Other times I simply couldn’t replicate the same great taste for a coffee I’d had at work in my home. I varied the recipe, tried to compensate for certain differences but never really solved the problem…
The study looked at how three elements of water affected flavours in extraction: hardness (the amount of calcium, magnesium, carbonate, and bicarbonate in water), pH levels, and total dissolved solids (TDS).
The biggest effect on flavour was achieved by modifying the hardness of the water
Dr Adam Carr of Seven Miles Coffee Roasters
They brewed an espresso on an industry standard machine from La Marzocco and then measured the concentration of chemicals in the coffee that are attributed to certain flavour characteristics, such as nutty/roasted (2-methylpyrazine), fruity (furaneol), vanilla/caramel (vanillin), and caffeine/bitterness (caffeine).
They found what I had sort of self-analysed by drinking coffee made with desalinated water, some mineral water and very hard (dH) water in my hometown in Bussum (dH around 9-10).
pH tends to concentrate flavors, much like salt enhances flavors in food
Higher pH tended to concentrate stronger flavours in coffee, though not to the same extent as hardness. However, higher pH levels also led to issues in the extraction process.
Scientists have finally answered a burning question of mine: why should an espresso be brewed in 25 +/- 2 seconds and use approx 15-22gr of dry coffee to yield 50ml of (a double) espresso?
Who came up with this rule and why? Not that I have a specific problem with it but it seems so arbitrary. Also, once you start to make espresso’s a day long, you’ll notice that it’s really hard to dial in the equipment a certain way and maintain those rules for every cup. Sometimes it’ll be 21 seconds, sometimes 29. The grinder is pretty accurate. The beans are practically the same. So where does this high variation come from?
Well, it turns out that brewing your espresso differently yields the same great taste and flavors while achieving this with much greater consistency and reducing the cost per cup of espresso!
How did they do it? Well, they started by reducing the process to a proper model with solid mathematics behind it. Brewing an espresso is basically fluid dynamics of a bed of particles. The “puck” being coffee grinds of varying sizes and water is pushed through this bed at a certain pressure.
These mathematics are very well understood and accepted. So the scientists started with this model, created equations for everything and solved the equations using differential equations. That resulted in a few parameters and then they found the optimal solutions.
Sounds easy enough but believe me the math is pretty impressive, yet their logic is sound.
Turns out if you lower the pressure to 6 bars instead of 9, use 7-15gr of dry coffee, ground more coarse then tradition tells you to and aim for an extraction of 8-15 seconds, you will get a beautiful espresso that is much easier to reproduce!
Dutch newspaper NRC did an investigation into the total energy it takes to produce a cup of coffee. By total they mean the LCA, Lifecycle Assessment, from growing to harvest to transport and roasting to you making your cup.
You will be surprised to learn what the most energy efficient type of coffee is. I.e. the least amount of energy required to make one cup of coffee…
No Pressure Coffee 