Have you ever experienced bitter coffee? Or maybe the question should be have you ever had coffee that isn’t bitter? It seems that almost everyone who has drunk coffee has had “bitter coffee” and the few individuals who don‘t enjoy coffee can attribute that to coffee’s “bitterness”.
The taste of coffee is determined by many variables, at every stage of the process. The amount we use the word ‘variables’ in the industry from farm to cup becomes a bit redundant, yet necessary. In order to understand what “bitterness” is in coffee and where it comes from, we’re going to look at a number of variables that can be causing it.
Most individuals don’t like bitter coffee, which is why cream and sugar has traditionally been a major player in coffee drinking. Think about those people who love the aroma of coffee but just don’t like the taste! It’s a real thing.
However, there are a few rare souls who enjoy bitter-tasting notes, luckily for the rest of us, bitterness in coffee can be avoided. The degree of bitterness can vary depending on multiple factors, and as usual, is all in the details. Let’s take it back to the beginning and start with where the coffee is grown.
There are 2 main types of coffee beans, you may have heard of them: Arabica and Robusta. Traditionally, Arabica beans are a higher quality coffee. Its characteristics often lead to less bitter coffee than Robusta beans. Arabica is often superior in taste and that demands a higher price.
Robusta can often be found in cheaper coffee, usually found in tin cans in your local grocery store and now commonly used in automatic machines such as Keurig or Nespresso. Robusta coffee is naturally more bitter than Arabica beans, as they contain higher levels of bitter compounds such as chlorogenic acid and lactones.
I use words like “traditionally” and “often” because, in recent years, many coffee farmers have been working at growing high-quality robusta beans.
Different Shade of Coffee
There are many different types of coffee trees. Their varieties include Gesha, Typica, Bourbon, among others. There aren’t specific varieties that are “more bitter” than others, however, there are plants that are sweeter. Gesha and Bourbon typically have more sweetness and are sought after by coffee buyers and roasters alike. Especially in the last couple of decades, coffee professionals have been blown away by the sweetness that can be in a final cup - to the point that sometimes this puts unnecessary pressure on coffee farmers. But that’s for another blog :)
The health of the coffee trees, nutrition of the soil, sunlight and of course water, are all factors as well. These all add different layers to the quality of the coffee.
Timing is everything; coffee cherries are usually picked in 4 parts during harvest. The best cherries, with the highest sweetness, are in the 2nd and 3rd pick. Leaving the lower quality cherries and that may carry some bitterness in the 1st and 4th pick. Even mother nature plays favourites, and you can’t fight her on that!
Processing and drying is another stage that is just as important, removing the cherries pulp from the seed is a delicate process. As you know, a “delicate process” means it is more expensive, many commercial coffee processors use efficient techniques that strip away some of the sweetness and quality of the final cup. Drying is just as important. Coffee has an ideal moisture content, if the green coffee gets too dry, like most things, it will lose flavour leaving it underwhelming or less desirable.
Roasting to Perfection
Let’s get to something a little more relatable! The roasting techniques play a major role in how your coffee is going to taste. This is why we are meticulous in our process and give each roast the care and attention to detail it deserves.
During the roasting process, there is a maillard reaction that takes place. This is a chemical reaction between amino acids and reducing sugars - this is what makes the coffee turn from green to brown. You see this commonly on seared foods such as fish and steak!
This means the longer coffee is roasted, the more sugar is burned off making the coffee taste more bitter. Dark roast coffee will always be more bitter than lighter roasts.
Why does really dark coffee exist?
Many commercial-grade coffees are over-roasted to try and hide other discrepancies within the coffee, leaving the coffee tasting quite bitter and explains why people add cream and sugar. By over roasting coffee, you are able to conceal the quality of the coffee. If a roaster purchases low-grade coffee beans, they can hide the taste by roasting past the 2nd crack. This is when beans become very oily and have a chalk-like substance.
Importance of Home Brewing
After all that, it comes down to the last stop - Brewing!
The final stage that bitterness can enter the scene is brewing the coffee. You can search the world for the best coffee, only to have a bitter taste left in your mouth! This is where over-extraction comes in. Coffee sits on a scale of sour to bitter, and we’re always aiming for that sweet middle spot that has the perfect mix of both that create a desirable experience.
Over-extraction takes place when coffee is brewed too long, the grind size is too small or the amount of coffee you are using is too high. When water is added to coffee it becomes a solvent, pulling out the tasting notes. The acids are first pulled out, followed by the sugars and leaving the bitter compounds for last. All 3 stages are vital to a delicious cup of coffee, however, if the 3rd stage goes over its peak amount, you are left with bitterness in the cup.
Simply put, there are more than a few of the variables that affect the final taste of a cup of coffee. Luckily we take care of most of the steps, and we are happy to help provide the best information so you too can brew coffee like a professional!
We know you want to get the most out of your coffee and have an enjoyable experience. Check out our brew guides for brew tips on how to make coffee in a french press, AeroPress and more! You can download the link and save it on your phone for when you make your next brew.
The best way to avoid bitterness in your coffee is to buy from a specialty coffee roaster like ourselves. If you would like to discover which of our coffees you might enjoy, try our adventure box that has 4 different samples or reach out to us firstname.lastname@example.org or @roadcoffee on social media and we’d be happy to recommend a coffee pairing!
Author Alisha Esmail