Multi-processed coffee blends: Do they enhance or dilute flavour?

A staple of roasteries, coffee shops, and even competitions, blends can offer both consistency and differentiated sensory experiences. According to a recent Perfect Daily Grind poll, 56% of respondents said they opt for blends to try new flavours, with 30% looking for a product that is “better than the sum of its parts”.

Roasters can approach blends in a number of ways. The most common method is to combine multiple single origins – whether different countries, regions, or farms – to create a well-rounded, balanced flavour profile.

Blends may also contain lots that have been processed differently, whether intentionally or arbitrarily. Washed, natural, honey, and experimental processing methods all have a huge impact on flavour, which influences the outcome of the final product.

Given the varied tasting notes of different processing techniques, blending them requires great skill and attention to detail. Combining the delicate flavours of a washed Colombian with a natural processed “fruit bomb” Ethiopian, for example, may not always yield the best results – drowning out the former or diluting the latter and creating a “lesser-than” product.

To learn how roasters can avoid these pitfalls, I spoke to Ashlee Eastwood-Quinn, Head of Coffee at Rave Coffee.

You may also like our article on how blends can reduce waste.

Processing methods & flavour

Experimentally processed coffees have made their mark on the industry over the last decade or so. Techniques such as carbonic maceration, thermal shock, and anaerobic fermentation yield wildly complex and intense sensory profiles that pique the interest of consumers looking to experience new, differentiated coffees.

As a small but growing number of producers have started to leverage these advanced processing methods and open up the possibilities of coffee flavour, it can be easy to forget how the traditional “big three” processing techniques also vastly influence the way coffee tastes:

• Washed – the skin, fruit, and mucilage are removed to result in clean, bright flavour profiles that best showcase the terroir of the coffee
• Natural – the skin and fruit are left intact while the coffee dries. This creates intense fruity, sweet flavours
• Honey – sitting somewhere between washed and natural (depending on the level of fruit and mucilage left on the beans), honey processing helps develop fruity flavours with more rounded acidity and sweetness

Although processing methods greatly impact flavour, origin tends to be the main focus when creating blends. Roasters often discuss how and why they combine multiple coffees from different producing countries to create a more balanced product overall. 

Popular combinations include Central and South American beans with African coffees, mixing the former’s typically chocolate and nutty flavour notes with the latter’s more fruit-forward ones. Blends can then provide consumers with more consistent and dependable sensory profiles, as opposed to single origin offerings, which are more impacted by seasonality and can, therefore, change more frequently.

Because of the greater emphasis on origin, roasters often share less information about which processing methods are included in their blends. For the sake of transparency and educating consumers, this presents an opportunity for the industry to be more intentional with blends.

Why combining different processing methods in blends isn’t so straightforward

Creating high-quality blends requires care and attention to detail. In addition to origin and seasonality, many other factors must be considered, including availability, variety, bean density and size, roast profile, and solubility (or how “easily” the coffee is extracted).

Processing, however, has arguably the biggest impact on flavour. With different methods resulting in a broad spectrum of tasting notes, and even mouthfeel and aftertaste, including multiple coffees processed in different ways in one blend poses some challenges.

Ashlee Eastwood-Quinn is the Head of Coffee at UK roaster Rave Coffee, which sells both single origins and blends.

“We often use coffees processed in different ways to make blends for many reasons. Whether it’s to achieve a specific flavour profile, to offer more accessible and versatile options, or simply to have fun with coffees that are very different from each other,” she says.

“Blending a washed and natural coffee, for example, can result in a coffee that is fruity and floral but also chocolatey and sweet,” she adds. “While this doesn’t necessarily showcase a particular coffee origin or processing technique, it can create a balanced blend that is more than the sum of its parts.”

But losing balance can quickly become an issue if roasters aren’t mindful of ratios and flavour intensity, creating a mish-mash of flavours and aromas that may not resonate with customers.

 A 50-50 split of washed and natural processed coffees, for example, may not always produce the results roasters expect. The robust fruitiness and sweetness of the latter are likely to drown out the more nuanced sweetness and acidity of the former, misaligning with customer expectations and even misguiding consumers who want to learn more about different processing methods.

Better than the sum of its parts: Why flavour balance is key

Different processing methods result in a diverse variety of flavour profiles, ranging from clean, bright fruity tasting notes to intensely fermented flavours. Combining more than one processing method in a single blend can yield interesting results, but it requires a careful approach.

“I think using different processed coffees in one blend can enhance or dilute flavour, so you have to make sure that each blend component is there for a reason,” says Ashlee. “Traditional blending masks poor quality coffee or to create generic flavours, so you should have a clear idea of why you select each coffee and how it behaves in and adds to the blend.”

Following best practices for blending is a useful starting point. Sweet Maria’s recommends using no more than five different coffees per blend (also a cost-effective strategy) to avoid overloading flavour combinations. 

“Keep the ratios at levels where you can taste what each component is ‘doing’ in the blend,” Ashlee adds. “Sprinkling only 10% of one coffee in means you will most likely lose its impact on the end result.”

Moreover, roasters need to consider what the blend will be used for. The pronounced body and fruity flavours of natural processing often work well for espresso, so increasing the ratio of these coffees for espresso blends may be advantageous.

At the same time, if the blend also contains washed or honey processed coffees, roasters must be mindful of retaining their more nuanced characteristics. Otherwise, they risk losing product integrity, so selling the coffee as a single origin may be more beneficial.

Should roasters avoid using certain processing methods? 

The challenge of balancing the flavours of different processing techniques raises the question of whether some don’t necessarily work well or overpower other blend components.

“I think the only processes that rarely work well in blends are those that have delicate or heavily fermented flavour notes,” Ashlee says. 

She adds that along with processing method, cup score and quality are important factors that determine which coffees may work better as single origins.

“Typically, the higher quality the coffee is, the less likely you are to use it in a blend,” she adds. “You might waste an exceptionally complex and high-scoring coffee as you would lose some of its distinctive flavour and nuance. 

“A perfectly good, but perhaps more one-dimensional, coffee can be a real asset to a blend. Its one great quality (perhaps nutty flavour) would be well complimented by a naturally sweeter coffee – and it’s these combinations that enhance the final product.”

The growing popularity of specialty coffee blends has pushed roasters to experiment with new and exciting combinations. Pairing different processing methods is one option, but it can be all too easy to compromise flavour and quality.

Finding the right balance of different processed coffees is key. Continuously cupping and amending multi-processed blends is the best way to achieve this, making sure different elements of each processing technique complement one another.

Enjoyed this? Then read our guide to roasting specialty coffee blends.

Perfect Daily Grind

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