Roasted Coffee: Everything You Need to Know
Here at Those Coffee People, we believe there’s nothing better than the smell of freshly roasted coffee. Not only does roasting coffee beans give them their wonderful aroma, but also their delicious flavor. In fact, without roasting, coffee beans would taste, well, less than ideal!
Given that roasting the beans is such an important part of coffee production, we’re going to walk you through exactly how it’s done, step by step. We hope this will help you understand the intricacies of the roasting process, the machinery needed, and how to achieve different flavor profiles. So, pour yourself a cup of your favorite roast and keep reading!
How Long do Roasted Coffee Beans Last?
Once roasted, coffee beans should sit on a cooling sieve to cool down. With specialty machine-roasted coffee, it is common practice to leave the beans for a couple of days to “degas,” that is, release the carbon dioxide that builds up inside the bean while the coffee is roasting. This process guarantees your coffee will stay fresh and aromatic, and can last between a couple of days and two weeks.
If you roast your beans at home, allow them to sit for at least four days before transferring them to an airtight container. Alternatively, you can immediately put the beans into a bag with a small one-way valve, designed to allow carbon dioxide to escape and prevent oxygen from entering. Experts say you should leave beans for between a day and a week before grinding them..
After this, the duration of freshness for roasted coffee beans depends on whether they are ground or whole, and whether or not the bag has been opened. If they are ground, coffee beans need to be used up quickly: a matter of hours in order to maintain the full flavor profile of the beans. For highly specialized coffees, some believe that ground coffee should be brewed within minutes.. If the bag is sealed, the ground beans will last for years and not perish, though it’s worth remembering that the longer they are stored for, the more stale they will taste.
If they are not ground, fresh roasted coffee beans can last for years in their sealed packaging without perishing. For specialty coffees, the best time to grind and consume the beans is within the first month after they have been roasted. The beans generally lose their value as a high-grade coffee after up to a year of storage, and from this point on they can be sold as standard commercial beans. Once opened, the roasted coffee beans should be ground and used within a timeframe of one month, at the most.
How to Roast Coffee Beans
Roasting coffee beans is a fascinating process that requires both attention to detail and precision. In commercial coffee roasting, there are three main stages: the drying stage, the caramelization stage, and the development or roasting stage.
- The Drying Stage: Green coffee beans in their raw, unroasted form, typically have a humidity level of between 10% and 12%. Before the roasting process can begin, the moisture in these beans must dry out. Once in the roaster, the drying process can last anything between roughly four and eight minutes and usually is carried out at a relatively low temperature, at around 160 degrees celsius.
- The Caramelization Stage: This is the stage where a process known as the “Maillard reaction” begins to take place. A chemical process that also applies to other foods besides coffee, this is the name given to the reaction between amino acids and reducing sugars to create compounds called melanoidins. These compounds give a distinct flavor to browned food.
- At the end of the caramelization stage, an important moment in the coffee roasting process takes place: the “first crack.” This breakthrough signifies that the color of the coffee beans is beginning to change and is accompanied by a sound similar to that of popping popcorn. But be careful not to over roast your beans! From this moment on, it only takes only a matter of minutes to achieve your desired roast profile, which we’ll talk more about later.
- The Development/ Roasting Stage: At this stage of the process, the chemical reactions inside the coffee beans go from endothermic — when they are absorbing heat — to exothermic — when they start to produce heat. The coffee will continue to crack during this stage.
Though coffee roasting is normally carried out using a commercial roasting machine, coffee beans can also be roasted at home in an oven, stove top popcorn popper, or a pan. The results, however, can vary. For a more effective roast we recommend using a specialty coffee roasting machine. Keep reading to find out why.
Are you interested in buying wholesale green coffee beans for roasting, directly from their origin in Colombia? We’ve got you covered.
What Does a Coffee Roasting Machine Do?
Despite their high cost, industrial-sized coffee roasting machines are essential for a coffee business looking to conduct high-volume roasting.
Investing in a coffee-roasting machine has several benefits. You can expect:
- A faster roasting time
- Consistent results
- Better energy efficiency
Generally speaking, there are two different types of coffee roasting machines. Next up, we’ll explain exactly what they do, how they work, and how they differ.
- Traditional Drum Roaster: These machines heat up a drum with a direct or indirect flame, and this drum then rotates. The coffee beans move around inside the drum. As a result, the beans receive conductive heat not only from the heat of the drum itself, but also from convection — when heat transfers through the movement of heated air. The temperature inside the drum can be adjusted to control how much heat is being transferred to the coffee beans, which can be measured using temperature probes. Using a drum roaster is a reliable way of achieving an even roast, and they work particularly well for producing dark roast coffee.
- Fluidized Bed Roaster: These roasting machines only rely on convection to heat the coffee beans. Fluidized bed roaster machines work by heating air and pushing it through the beans in order to roast them. Not only do they generally use less energy than drum roasting machines, they will also roast the coffee faster. Fluidized bed roasters generally achieve a better light roast coffee, although they tend to be more expensive than drum roasters due to their complex machinery. Unlike drum roasters, most fluidized bed roasters do not allow you to look at the coffee beans during roast.
Commercial coffee roasting machines are not only expensive to purchase, but they are also large and require a significant amount of space to house. If those factors are a sticking point for your business, you might consider clubbing together with a few other coffee businesses to split the investment and share the roasting machine, taking turns to use it. Some coffee roasters are also available to rent at an hourly fee. Otherwise, you might consider purchasing pre-roasted, white labeled coffee to sell to your customers.
Either way, roasting machines are essential if you wish to precisely control roast time and roasting temperatures, both of which allow you to adjust the flavor profile, or roast profile, of the coffee beans. More on this in the next section.
Looking for roasting and white-labeling services? Here at Those Coffee People, we have helped hundreds of business owners purchase white-labeled coffee directly from Colombia.
What is Light Roast Coffee?
Though the flavor of roasted coffee is graded based on around 10 different elements, flavor profiles can be broadly grouped into three main characteristics:
- Level of bitterness
- Level of acidity
- Origin characteristics: Where the coffee is grown, how it’s processed, etc.
Simply put, light roast coffee is coffee that has spent less time in the coffee roasting machine, at an overall lower temperature. This means that the coffee beans have generally not roasted long enough for them to caramelize and produce sugars and oil, making them light brown in color and giving them a matte finish.
In terms of its flavor profile, light roast coffee is — as its name suggests — lighter in body. A favorite among coffee connoisseurs, light roast coffee also has the advantage of highlighting unique flavors in the coffee beans, making it easier for drinkers to detect and savor them.
Crisp and bright in acidity, light roast coffee tends to be sweeter, revealing more floral and fruity notes than medium roast or dark roast coffee. A light roast also allows the origin characteristics to shine through, which is why this style of roast works much better with high quality, specialty coffee beans. A light roast of poor quality coffee beans will allow all the defective notes to shine through in the coffee, making the drinking experience distinctly unpleasant
And, a fun fact is that light roasts contain proportionately more caffeine than dark roasts, so if it’s an energy boost you’re after, light roast coffee is for you!
What is Blond Roast Coffee?
Some coffee roasters like to break down the light roast coffee flavor profile into different sub-roasts.
Broadly speaking, the three different categories of light roast coffee include:
- White roast: These coffee beans are actually taken out of the coffee roasting machine before the “first crack.” This is among the shortest amounts of time that coffee beans can be roasted for, making this flavor profile even lighter than a typical light roast.
- Gold roast: This type of roast describes coffee beans that have been left in the roaster for slightly longer than a white roast, giving them a smoother flavor.
- Blond roast: Still among some of the lightest roast coffee you can brew, this roast profile boasts more acidity than the previous two.
What is Medium Roast Coffee?
As the preferred roast profile in the US, medium roast coffee boasts a well-rounded flavor; still managing to preserve origin characteristics while hinting at some of the silkier notes of a dark roast coffee, without the chocolatey darkness which comes from the burn of a dark roast. If you’re looking for a full-bodied roast and the ability to still detect flavor complexity from the coffee, medium roast coffee is for you.
Like light roast coffee beans, these beans do not yet appear oily or shiny. As the beans roast for longer, edging towards a medium dark or dark roast, chlorogenic acids inside them begin to break apart, leading to a caramelization of the beans and producing the bitterness that is so characteristic of dark roast coffee, meaning they lose their matte finish.
However, just because coffee beans have been roasted for longer does not mean they contain more caffeine. In fact, quite the opposite! As we mentioned above, light roast coffee actually contains more caffeine than dark roast coffee.
Here at Those Coffee People, we recommend storing your coffee beans in a cool, dry place, elevated slightly off the floor, and away from direct sunlight in order to guarantee maximum freshness. In sum, we believe it’s fair to say that the perfect cup depends on the perfect roast. We wish you all the best with perfecting this key step!