A 4-Step Guide To Roasting Kenyan Coffee


Kenya is Africa’s fifth-largest coffee producer, and its six producing regions are known for producing a wide range of high-quality coffee varietals, owing to the country’s high altitudes, moderate temperatures, consistent rainfall patterns, and volcanic soil.

While its coffees are known for being complex, fruity, full-bodied, and acidic, developing this flavour profile to its full potential is dependent on how the coffee is roasted as much as it is on the origin and inherent qualities of the coffee.

Here’s what distinguishes Kenyan coffee and what to look for when roasting it.

What Makes Kenya’s Coffee Unique For Roasters?

To get the most out of their green beans, roasters must be careful when selecting them, as the type of beans used will affect the roast outcome. Here are a few factors that are specific to Kenyan coffee beans.

Bean Size Is Important

Kenyan coffee is sorted and graded by size, with common categories including E (Elephant, the largest bean found in Kenya), PB (Peaberry), AA (the largest specialty bean), and AB (the smallest specialty bean) (a mixture of large A and slightly smaller Bs). After sorting by size, beans are graded by quality on a scale of one to ten and divided into different lots.

The type of beans you buy will influence how you roast them. Mikkel Selmer is the Head of Coffee at Denmark’s La Cabra Coffee Roasters. He suggests that when roasting AA beans, consider their higher density and reduce batch size. Eros Ceresa is Falcon Specialty Coffee’s Green Bean Buyer, and he understands the size differences between different grades of Kenyan coffee beans. While there is no significant difference between AA and AB, he claims that PB will necessitate a different approach to charging temperature and how heat is applied and then reduced during ROR descent. He keeps the temperature low here to prevent the smaller beans from tipping or scorching.

How Processing Impacts Your Roast

Many Kenyan coffees are processed, and while many people still prefer the traditional double processing methods, others prefer natural and honey processing. Casper Rasmussen, Co-founder of the Danish Coffee Collective, has some thoughts on this. “So far, we’ve only had experience with pulped naturals from Kenya in our production,” he says. In the roaster, they acted surprisingly like a normal washed Kenyan. Normally, a natural must be roasted differently than a washed.”

Natural and honey-processed coffees, according to Eros, can be roasted slightly lighter than washed coffees. “If I’m trying to stay as light as I do for a natural, my washed coffee will have the herbal, creamy, grassy flavour,” he explains.

Knowing the characteristics of your beans and how they were developed will keep you from making costly mistakes and will ensure that the beans you choose will release the flavours you want to highlight with roasting.

Managing The Roasting Process

Having a predetermined flavour profile in mind and understanding what you want to stand out in a cup will help you guide your roast to where you want it to be will help you guide your roast to where you want it to be. Using your previous experience roasting other beans and having a general idea of how to get there is a great place to start, as is understanding that adjustments will always be necessary throughout the process. It’s also worth noting that when it comes to roasting this bean, most roasters have their own ideas and thoughts.

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Mikkel describes roasting Kenyan coffee as “undiluted Ribena juice.” “It’s easier to distinguish that fresh blackcurrant note that we want in a light roast… so that’s what we aim for… we look for cleanliness and, importantly, that sweet and sour balance,” he adds. He continues, “[Kenya] is one of the countries we buy coffee from where we have the clearest idea of what we’re looking for in terms of cup profile,” adding that while he usually focuses on density over origin when roasting.

Casper, on the other hand, discovered that because we know what flavours to expect from a Kenyan bean, we can look more closely at their individual characteristics. “As with all coffees we source, we look for sweetness first and foremost,” he says. For us, this is the best indicator of how well the coffee is produced.”

Keep your customers’ preferences in mind, as coffees with too much of a “sour” flavour may turn off many potential customers, whereas coffee connoisseurs with more experience tasting specialty may expect its bright fruity punch.

The challenge is to create a profile that appeals to everyone. However, there are a few general guidelines to follow regardless of who you’re roasting for.

  • Drop Temperature – Because Kenya’s AA beans grow at such high altitudes, they produce a very dense bean. This means you’ll need a drop temperature high enough to generate enough energy to finish the roast.
  • The drying phase – if you want to keep your coffee’s fruity acidity without giving it a heavy body, shorten the drying phase by applying extra heat shortly after the roasting point.
  • The Maillard phase – to keep the acidity from overpowering the coffee, the tartness must be balanced with some sweetness. Extending the Maillard phase will aid in achieving that balance.
  • Roast Time – The longer the roast, the more body produced. Finding the right length of roast may take some practise, and it will also depend on whether you’re roasting for espresso, filter, or omni.
  • Development time varies depending on the length of your roast and the extraction method you use. Shorten the development time to retain as much acidity as possible, but make sure the bean fully develops – failure to do so can result in too much fruity acidity. “Don’t be afraid of building up heat as you approach the first crack,” Eros says. If you don’t have enough heat to sustain the second part of the development… you’ll end up baking the coffee, which will completely cancel everything.

Finishing off Your Roast

Your coffee should have enough time to degas after it has been roasted. Because of their higher density and lighter roast, they can slow the degassing process, which can take up to a month for full flavour development.

If you intend to use it in a blend to balance or complement another coffee, keep in mind that Kenyan coffees can have far too much acidity for the average espresso drinker, and can even curdle or sour a milk-based beverage. This will allow you to sweeten your roast while reducing its natural acidity. The complex, delicate acidity of a high altitude Colombian coffee would balance a Kenyan coffee.

Casper has been experimenting with a Kenyan blend for quite some time. “As for any coffee for brewing as espresso, we tend to have a longer profile to ensure that the brew does not become too acidic,” he says. A Kenyan coffee can be overpowering at times, taking all of the attention away from the other coffees.”

While Mikkel and Casper approach roasting in different ways, they both agree that it begins with sourcing high-quality coffee. Mikkel advises looking for high-quality beans and adhering to your roastery’s existing quality control procedures, and Casper adds that roasting a quality green coffee is much easier.

To uncover its full potential and create a clean profile free of roast defects, roasting Kenyan coffee requires fully understanding it and treating it with care. While following the steps above can help finetune your roasting efforts, each batch must be treated individually, and just because you have previously roasted a Kenyan coffee does not guarantee that you will get perfect results with a similar profile right away. Want To Learn How To Start Roasting Coffee At Home? Here’s The Guide You Need

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