Slow Roast vs Fast Roast: Which Is Better?
Slow roast vs fast roast – Let’s find out which is best. The coffee community has always been divided by their different preferences, and that means that neither one of them is right or wrong, just that all opinions are deviating.
In this article, we will talk about a highly divisive topic: slow roast and fast roast. We will try to give you an answer to the question, “Is slow roast or fast roast better?”
Slow roast is better for people who prefer subtle acidic tones with a less concentrated flavor. On the other hand, a fast roast is preferable to people who value time, efficiency, and an aggressive acidic tone in their brew.
This article will discuss the differences in preparation of a fast and slow roast and their resulting brews. So, without further ado, let us get the roasting started!
Slow Roast vs Fast Roast: Is it better to roast coffee fast or slow?
Roasting coffee does not have a specific static method for everyone. Instead, it heavily relies on the coffee beans you have, the roaster machine you have on hand, and your personal preferences in taste.
In this section of the article, let us discuss the differences and the pros and cons of roasting your coffee fast or slow.
Acidic or Non-Acidic
In coffee land, acidity is either preferred or heavily despised, and the type of roast can significantly affect how much acidity is within your cup of coffee. The relationship of the duration of the roast to the amount of acidity inside a cup of coffee is not a trade secret.
It has been known that roasting your coffee for longer can reduce acidity, which results in a more neutral, bitter flavor. On the other hand, having your coffee roasted fast results in a higher amount of acidity within your brew.
The acidity is reduced on longer roasts since organic acids will have more time to break down. Having many organic acids will result in more distinct flavors and carry acidity with them.
Concentrated or Less Concentrated
Another relationship in the taste of coffee with the duration it is roasted is within the concentration of the flavors within the coffee at hand. The longer a coffee is roasted, the more bitter it is.
Coffee roasted fast usually results in a more aggressive acidic flavor with a bit more mellow bitterness, yet overall is fuller in flavor. On the other hand, slowly roasting your coffee will give you a milder acidity and a strong bitter taste with less concentrated flavors.
Control vs Efficiency
Since you are roasting your coffee at faster rates, fast roast coffee will improve efficiency in the sacrifice of control. But, on the other hand, it would mean that if you have certain organic compounds that you personally dislike the taste of, you might need to opt for a longer roast.
With longer roasts, you will modify some flavor notes of coffee as the entire process is stretched out longer and gives you a better overview of the whole process.
However, big roasting companies may favor a fast roast process for its efficiency and consistency in flavor. And there will be less leverage to work with on fast roasts.
If you are new to roasting, most coffee aficionados will suggest you not work on fast roasts. Despite their efficiency and consistency, fast roasts are notoriously challenging to deal with as you will have higher chances to burn your coffee beans.
The type of roasting machine you are using
The type of roasting machine may make or break your decision on what type of roasting method you should use. Since design heavily affects the thermodynamics of roasting, you should take note of machine structures and design.
It is much better for those using a traditional drum roaster to use the slow roast method. This is because traditional drum roasters burn the beans if the heat is too high.
If you are using a fluidized bed roaster, you should make use of a fast roast. Since the beans are indirectly heated by hot air, the notoriously difficult to control fast roast will now be significantly more manageable thanks to such innovations.
In addition, these types of roasters can produce high heat without burning the beans.
The art of roasting: how are fast and slow roasts achieved?
In such a delicate art form, the taste of coffee is at stake. Fast and slow roasting results in different flavors of coffee, mainly as a result of their vastly different methods of roasting. In this section of the article, we will discuss the different methodologies of fast and slow roasts.
Before we proceed, let us first discuss a crucial factor in roasting coffee: the first crack. The first crack is one of the visible/audible reactions during the roasting of coffee, making it a critical progress marker during the roasting process.
The first crack is renowned by roasters as it is straightforward to spot compared to the other chemical process, which will only be subtle at best. The first crack is named as such because of its notorious “crack” whenever roasting coffee.
The first crack is an important indicator when roasting coffee, and the time it takes to achieve the first crack varies greatly with slow and fast roasts.
In slow roasts, low heat is used to roast the coffee until the first crack, which usually happens at temperatures of 400°F to 420°F (204°C to 216°C). After the first crack, the heat is turned up until the beans have finished roasting.
Contrary to the slow roasts, fast roasts are produced using high heat first, like searing a steak, which is then turned to low heat after the first crack is achieved. At this point, the beans can roast themselves as they have achieved a high amount of temperature.
Most of the time, from start to finish, a slow roast typically takes 14-20 minutes. On the other hand, a fast roast is incredibly speedy, especially when compared to a slow roast. The fast roast will take only most of the time 90 seconds, an incredible improvement from 20 minutes.
Below, we have displayed a table to easily distinguish the slow roast and fast roast from each other. We also have added information discussed prior.
| Slow Roast | Fast Roast | |
| Taste | Less full-bodied, more controlled flavor. It is less acidic but typically more bitter. | Has a more concentrated, consistent flavor. Acidic but less bitter. |
| Speed | Takes 14 to 20 minutes from the start of roasting to the end of roasting. | Takes just 90 seconds throughout the whole period of roasting. |
| Degree of Control | Has more control of taste, easier not to burn. | Very easy to burn, provides a more consistent result. |
| Machine Type | Appropriate for Traditional Drum Roasters. | Easily achieved with Fluidized Bed Roasters. |
Can you roast coffee too fast?
If you want to achieve a very concentrated, fuller flavor coffee, you may opt for a very fast roast. However, roasting a coffee too fast will result in many mistakes that are out of your control. So for the question, “Can you roast coffee too fast” the answer is yes.
Roasting coffee too fast will result in an uneven flavor. Just like how frying a frozen breast too quickly will result in a half-cooked chicken, roasting coffee too fast will result in different flavor profiles, and you may be greeted with a coffee bean that’s a light roast and a dark roast at the same time!
Additionally, since the duration of roasting is connected to acidity, you may be greeted with a highly acidic flavor. Ensure that your coffee is roasted correctly, break apart a bean, and make sure the color is consistent throughout.
Roasting frequently asked questions about roasts.
What coffee roast has the most caffeine?
Dark roasts are typically more substantial when it comes to their ability to pack a punch. However, most of the time, light and dark roasts have more or less the same caffeine content.
What roast coffee has more flavor?
Just like fast roasts, light roasts contain the most concentrated amounts of flavors.
Which is lighter, fast, or slow roast coffee beans?
The oils and organic compounds have evaporated on slow roasts, thus making slow roast coffee beans significantly lighter than their fast roast counterparts.
