Kaffee rösten: Tipps für den perfekten Geschmack

The Coffee Roasting Process for the Perfect Taste

How do beans actually turn into the aromatic beverage we know and love? The key lies in the coffee roasting process. There are actually a myriad coffee roasting techniques, ranging from improvised methods to working with highly professional equipment.

Let's take a look at some coffee roasting basics, establish the most important facts, and give an overview of professional methods. We'll also tell you how to start roasting your own beans at home using simple methods like a pan or your oven. And of course, we have answers to frequently asked questions.

Put on your roast master’s apron and let’s dive right in!!

Why is coffee roasted?

Have you ever wondered why coffee has to be roasted before it is ground and prepared? In order to answer this, we wish to take a brief look at how coffee is grown and processed.

Coffee trees are grown in tropical areas around the equator, the so-called coffee belt, and the beans grow inside "coffee cherries". When these are ripe, they are harvested manually or by machine. Then, the cherries are usually dried directly in the sun until the beans can be extracted easily.

But the raw, green beans have little in common with the black beans we love so much for our daily espresso, filter coffee or other specialties. They taste grassy and a little bit like hay. They don’t develop their characteristic coffee flavor, aroma and texture until they have gone through the roasting process.

What Happens During the Coffee Roasting Process?

When the green beans are heated, their chemical properties change. The heat breaks down the cell structure and releases oils and acids that are responsible for the flavor. Depending on the degree of roast, different flavors will emerge, which are often described as chocolatey, nutty or fruity.

The following factors determine the final taste of the beans and grounds: the method and the “recipe” of the roast master, the type of coffee and the growing region.  We also distinguish between the various degrees of roast - from light to dark - and each one influences the taste of your favorite brew. Some love it light and fruity, others prefer it dark and strong - ultimately it’s just a matter of taste!

It’s truly fascinating to think about all the different steps, until you can hold a fragrant cup of coffee in your hand!

The Most Important Facts About Coffee Roasting

As a fan of the liquid gold, you should definitely know how important the coffee roasting process is to the taste of your favorite beverage

  • Each type of coffee has its own specific aroma and flavor profile, which can be accentuated or toned down by the method used in the roastery. Arabica beans, for example, innately have a milder flavor than Robusta beans, but of course that flavor is also affected by the technique used to roast them.
  • Gentle roasting is better than hot roasting: the longer the beans are exposed to heat, the more time they have to release acids and form complex aromas. Therefore, a longer roasting process at a lower temperature is preferable to a quick roast. A light roast results in higher acidity, while dark roasted beans have lower acidity. The remaining acids are also perceived as "softer" and more pleasant than the acidity in unroasted beans.
  • The duration of the process influences the taste: the longer the coffee is roasted, the darker and more tart or intense its taste. A light roast, on the other hand, provides a fruity flavor, but it contains more acidity than dark roasted beans. Dark roasts are therefore usually more easily tolerated.
  • Temperature is critical as it is an essential factor for flavor and aroma. If the temperature is too high, the beans might be roasted on the outside but still too raw on the inside and the coffee might taste burnt.
  • There are different degrees of roast, ranging from light to dark. Each degree of roast generates a different flavor, suitable for a specific method of preparation.
  • The method matters! When it comes to industrial production of coffee, we basically distinguish between two main methods, drum roasting and hot air roasting. Other methods are only used to roast small quantities of beans and are therefore most suited for use in private households. We will discuss these methods in more detail later in the article.
  • Timing is important: Freshly roasted coffee tastes best; once the aroma package is opened, coffee does not stay fresh for long and the aroma quickly fades. Therefore, it is better to buy coffee only in small quantities, which you can consume within a few weeks. If you roast coffee yourself, it's better to do it in small quantities.

If you take these facts into account, you will certainly enjoy your morning pick-me-up even more!

The Professional Coffee Roasting Processes at a Glance

In general, one of those two professional methods is used:

1. drum roasting

2. hot air roasting

In the hot air method, very hot air (around 1112 °F) is evenly circulated around the raw, green beans. This method is suitable for huge quantities of beans and takes only a few minutes, but the beans have little time to develop complex flavor and reduce acidity; therefore the final product generally has less depth and complexity of flavor. Typically, more inexpensive varieties are roasted using the hot air method.

Drum roasting, on the other hand, takes place in a closed container that rotates and thus ensures uniform roasting. The roasting is done at a lower heat, but the beans have to be roasted longer. This method is more gentle and the beans have enough time to develop their full range of flavors. Needless to say, Coffee Annan coffee is roasted with high-quality drum roasting.

How to Roast Your Own Coffee at Home

Do you want to start your own mini coffee roastery at home? For many aficionados, this is unimaginable, but it’s easier than you think and has some advantages. You have full control over the degree of roast and therefore the taste of your coffee. It's also a great way to get creative and discover new flavors.

We'll give you all the relevant information, if you want to know how to start roasting coffee yourself. Get inspired and enjoy your very own freshly roasted coffee soon!

No matter which technique you wish to try, you always need raw, green beans, which you can buy in select shops or online.

Always roast only as many beans as you will consume in about two weeks. Coffee loses its aroma quickly after it has been roasted. As a first step, you should wash the beans thoroughly and let them dry.

Roasting Coffee in a Pan or Wok

Put the beans in the hot pan and make sure that there is only one layer. They should not be placed on top of each other. It's important that you keep moving the beans around, so they roast evenly. After a few minutes, the beans will begin to crack. The "first crack" - the bursting of the beans, is considered the starting point of the aroma formation. At this point, you should reduce the flame a bit and continue stirring until the desired roast is achieved.

However, the pan method is not really recommended, as it is almost impossible to achieve an even roast. The following methods are much more likely to result in fragrant coffee beans.

How to Roast Raw Coffee Beans in the Oven

Is it really possible to roast green beans in the oven? Absolutely!  And it's super easy, too. Spread the beans evenly on a baking sheet and put it in the preheated oven at 428 °F.

Now it's just a matter of waiting and checking regularly. After about 5 minutes, the beans will start to crack and pop - a lovely sound. After another 5 minutes, the beans should be flipped and then baked for another 5 minutes. When the beans are a nice brown color, take them out of the oven and let them cool. That’s how easy it is.

Using a Home Roaster

Of course, there are also special devices for roasting coffee beans at home. There are many different models of coffee roasters on the market, so it is important to find out in advance which roaster best suits your personal needs. A good home coffee roaster will not only offer precise temperature regulation and control, but also options like a timer and an automatic shut-off for even more convenience while roasting.

Our Insider Tip: Roast Your Beans in the Popcorn Machine

A creative alternative to expensive home roasters is the popcorn machine, even if that might sound a little too adventurous for you. The popcorn machine also works with hot air, which is evenly distributed in the container, making it ideal for roasting coffee. Just put the raw beans into the popcorn machine and off you go! This way, you can easily roast your coffee according to your preferences.

Advantages of roasting at home

The biggest advantage is definitely the taste experience. You can roast your coffee the way you like it best. Plus, you have full control over the roast level and can experiment until you find your perfect blend. The aroma is also more intense since the coffee is truly freshly roasted. And just think, how proud you will be, offering a cup of home-roasted brew to your friends!

Disadvantages of roasting at home

For one thing, you need a certain amount of experience and good intuition to roast the coffee to perfection. Furthermore, the raw, green beans are not always easy to come by, as only select coffee dealers have them in stock.


1. Can Beans Burn during the Coffee Roasting process?

Sure, if you heat the beans for too long, at a temperature that is too high, or don't make sure they are constantly moving, coffee beans can burn. The taste suffers greatly, and they may no longer be fit for consumption.

2. How Long Does the Coffee Roasting Process Take?

The duration depends primarily on the temperature. The hotter the temperature, the faster the beans are roasted. The danger of a high temperature is that sometimes the beans do not have enough time to develop their full range of aromas; acids are insufficiently broken down, and the coffee can taste sour or bitter. Therefore, it is preferable to roast more slowly and gently.

3. Why Should Coffee Beans Not Be Roasted in a Pan?

It is difficult to achieve an even heat distribution when you roast in a pan, so your oven or special hot air roasters are more suitable.

4. How Long Should the Beans Rest After Roasting?

This is a question that concerns many coffee fans. Some coffees need more time to develop their flavors, while others show their aromas almost immediately after roasting. So be patient and try it out, let the coffee rest and unfold because after all, it's your taste that counts.

The Bottom Line

The coffee roasting process is a genuine art form and has a huge impact on the taste of our beloved pick-me-up. So if you're a true aficionado, why don’t you try your hand at being a master roaster yourself and experiment with different degrees of roast. There's nothing better than a cup of coffee that's just the way you like it!  Coffee Annan is at hand to supply larger amounts of perfectly roasted coffee for your private use and for the office, and it’s fairly traded to boot. Check out our coffee finder and discover your new favorite coffee.

If you are keen to learn more about the exciting world of coffee, feel free to read more posts on our site. We regularly address topics of interest related to our beloved liquid gold.

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