Coffee is bitter!
Do you know these moments when you brew a coffee in the morning or throughout your day, then take the first sips and recognize that your coffee tastes some-kind of bitter?
I'm not talking about the bitterness which can be a normal part of coffees (up to a certain level), but a more unpleasant taste requiring you to add some milk or sugar in your cup to make the coffee drinkable.
Or do you know this taste in your cup when you hardly can recognize the coffee-flavors because your brew tastes watery and looks more like some light-brown-colored beverage rather than coffee?
Well, often the reasons are to be found either in the roasting or the coffee brewing process or in both.
As the roast quality depends greatly on the roast master's abilities and you can hardly have a direct influence on it - except you roast your own coffee at home - it's crucial that you get a basic understanding on the coffee brewing process.
In this post you will learn the basic factors which influence coffee brewing and will serve you as the foundation to master a great brew - no matter which brewing method you're going to use.
#1: Coffee Brewing Ratio - Dose it right!
The coffee brewing ratio or coffee-to-water ratio is the response to a frequently asked question: how much coffee with how much water do I need for brewing a cup of coffee? With the great variety in brewing methods available today (e.g., coffee maker, manual drip brewing methods like Chemex, french press or stove top, among others), there is not the perfect brewing ratio which fits to all.
Nonetheless, in the 1950's the Coffee Brewing Institute (CBI) and later the Coffee Brewing Center (CBC) conducted researchs on brewing methods and different factors which affected the final brew.
As a result, it established some quantifiable guidelines, including the coffee brewing ratio or the final concentration of a brewed coffee. According to this researches and which serves as a pillar in today's speciality coffee industry, the ideal coffee-to-water ratio is:
55-60g of coffee with 1 liter of water OR 1g of coffee with 16ml of water. Hence, you would obtain a brew ratio of 1:16.
Now, I suppose that you don't want to brew always 1l of coffee at a time, especially if you're living alone or perhaps with your girlfriend or wife. So, the coffee brewing ratio will help you to adapt the quantities you need for the amount of coffee you want to drink and also for the amount your brewing method has capacity for (imagine a small cone dripper with 60g of coffee:))
You will not only be able to brew the right quantity, but also reduce your coffee waste. Especially, if you have a pricier coffee, it's recommendable to dose the coffee accordingly and use only as much as you really need.
Nonetheless, it's important to notice that this recommended ratio represents for you only a point of start. If you feel that the coffee gets too strong, you can change the ratio - e.g., 1:17 - and dose it accordingly.
#2 Grinding Coffee Beans - Get the right size!
Combined with the brew ratio the size of the ground coffee particles is an important aspect in coffee preparation. You need to grind coffee to facilitate the water to penetrate the small particles and extract enough flavor compounds in a reasonable time (if you want to try an experiment preparing a cup of coffee with whole beans, go for it and tell me your results :))
Basically, grinding coffee beans just means to increase the surface of the coffee for the water and thus making extraction faster.
The size to which a coffee should be ground depends heavily on the brewing method and the related brewing time. The brewing time is vital as the water needs to stay sufficient time in contact with the coffee to extract the necessary flavor compounds. Brewing for too long or too short, may alter negatively the flavor of your coffee.
As a rule of thumb, fast brewing methods such as espresso requires fine grounds. The reason is that the finer the grounds the more exposed the flavor parts are and the faster the water can extract them. For instance, in espresso-based preparation you have to extract all compounds in 18-35 seconds. That's really quick!
On the other hand, there are slow brewing mehtods such as coffee makers, hand pour-overs or french press, among others. The brewing time can vary between 2-5 minutes. The grounds can be coarser because the water has much more time to stay in contact with the grounds.
Starting from here, the grind size of the particles have to be adjusted accordingly in order to allow extracting the necessary flavors in a certain time avoiding over- or under-extraction (more about this in the third part of the series).
Matt Perger from Barista Hustle puts it like this:
"The most important thing to wrap your head around here is that grind size doesn't really change what is being extracted. It only changes when the things are extracted. All of the flavour is right there, in the coffee bean, ready to be extracted. Grind size just puts more or less of that flavour in front of the water right away."
#3: Respect the coffee brewing extraction cycle
When brewing a coffee, the extraction goes through different time phases. The first drops coming out at the pure beginning will give you an extreme acid taste. Acids are generally the first elements which water dissolves as they are high soluble. Here you have everything regarding bright, fruity acids.
After that, aromatic and more sugar-like compounds follow. Vanilla, chocolate, caramel and nuts can appear.
In the end, low soluble compounds are extracted giving a flavor such as ash, wood, tobacco and malt. They provide you with the bitterness. It's important that the brewing time takes only as long as you get to the bitter compounds. And stop. Probably, you don't want to extract everything! In a future article I'll explain you how to test this and fine-tune your preparation.
Heads-Up: a strong coffee doesn't mean that it has to be bitter.
#4: Coffee Brewing Temperature
The water temperature is vital as it helps you to extract enough flavor compounds at a reasonable time. The recommended water temperature, especially regarding the temperature in the coffee bed during the brewing process should be between 92-96 C (197-205 F).
A lower temperature can lead to an under-extracted coffee (sour), a higher temperature to an over-extracted coffee (bitter).
In my opinion, the temperature range is even narrower and should be between 92-94 C (197-201 F). However, there could be situations when the coffee brewing temperature cannot get to the target temperature, for instance, if you are at high altitudes. The effects of a lower temperature can be compensated by changing the grind, for instance.
#5: Water Quality
A cup of coffee brewed in a non-pressurized system (espresso machine), contains usually between 98-99% of water. That's why this ingredient is so important and often underestimated. But what does water quality mean?
In the end, it's the water's ability to extract the right flavor compounds of the coffee. This depends strongly on the chemical composition of water. I just wanted to raise your awareness about this. Just keep it in mind for now ;)
#6: Turbulence - move the grounds!
No matter how you prepare your coffee, the grounds need to be moved to facilitate the extraction. In Scott Rao's "Everything but Espresso" book he makes a great example of a tea bag. Just laying it in water, will extract the flavors, but not that fast. But moving the bag will help to extract the compounds faster.
In manual coffee preparation - e.g., pour-over or french press - the way you pour the water can create some turbulence. Also stirring the coffee or moving the dripper (check for the Rao Spin) is a way to accelerate extraction.
While the other factors are quantifiable, the tubulence or the technique you use is some kind of a trial and error thing.
#7: Coffee Brewing Methods and Filters - your hardware
First of all, you can use any kind of brewing method with any kind of coffee. There is not something like an "Espresso Coffee". The taste in one or another brewing method can be better or worse.
In my opinion this is subject to your personal preferences. The design of the method, the filter material and the porosity of the filter have a great impact on the extraction capacity, the clarity of the beverage and the body.
In other words, you can use one type of coffee in 5 different brewers. You will obtain different flavor profiles revealing also the characteristics of a certain brewing method.
#8: Educate yourself continuously and be passionate
That's the most genuine recommendation I can give you!
I've learned so much from all the great baristi, roasters and cuppers on their websites or in real life and I'm in a constant process of learning. So investigate, search for other opinions, different from mine and try out everything. In the end, I want you to really understand brewing and enjoy a great cup. I really encourage you to look after more information beyond this article.
The 8 mentioned points above give you a first inside to understand better what factors have a great impact on coffee brewing and how you can use it for your purpose.
Although, there are more factors influencing the final brew results, I wanted to cut down those points which you can really manipulate. If you think that your coffee has some potential, play around with some of the aforementioned points and I'm sure you will get a great brew.
Keep in mind that with this principles you are able to extract any kind of coffee. Good or bad coffees. But try to get quality coffee beans so that you can enjoy your brew and the versatility of coffee. Brewing great with bad coffees won't give you that satisfaction. Take the 8 points as the foundation for whatever kind of brewing method and as a starting point. Nothing is graved in stone!
And how do you brew your coffee? I'm curious to know more and if your coffee is still bitter ;)
In the next part, you'll get to know about the minimum necessary coffee brewing equipment you need to master coffee brewing and obtain consistency.
I hope this post was helpful and I would appreciate if you want to share your thoughts and experience about this. I'm looking forward to your commentaries below. If you think this post could interest or help some of your friends, then please share it.
Sage, E. (2013, October 4). The Coffee Brewing Institute: Setting the Stage for Specialty Coffee. [Blog] Specialty Coffee Association News. Available at: http://www.scanews.coffee/2013/10/04/the-coffee-brewing-institute/ [Accessed on 2017, April 17]
Grinding Fundamentals (2015, April 23). Coffee Chemistry. Available at: https://www.coffeechemistry.com/quality/grinding/grinding-fundamentals [Accessed on 2017, April 16]
Perger, M. (2015, February 8). Surface Area and Time. [Blog] Barista Hustle. Available at: https://baristahustle.com/blogs/barista-hustle/surface-area-and-time [Accessed on, April 17]
Rao, S. (2010). Everything but Espresso - Professional Coffee Brewing Technique. Canada.
Lingle R., T. (1996). El Manual de la Preparación de Café, (1,1). Long Beach, California.
Title picture by Karl Frederickson on Unsplash
Corrected & Revised by Andrea Letzner