What is SOE? What are Single Origin and Blended Coffee Beans? What Does Specialty Coffee Represent? Why Does Espresso Have Acidity?

What Is SOE, and Why Are Most SOEs Acidic?

SOE, meaning "espresso extracted from single-origin coffee beans," has become one of the hottest products in coffee shops in recent years. Although not every café's SOE is predominantly acidic, at least the vast majority are, which is why whenever we visit a new shop hoping for an acidity-driven espresso, we habitually scan the menu for an SOE option.

The Origins of SOEs and Blends

So the question arises: why are most SOEs acidic? To answer it, we need to understand the causal relationship between SOEs and blends.

Although SOE is a concept that only became popular recently, as early as the invention of the espresso machine, the espresso people extracted was already SOE. At that time there were no concepts like single origin, blend or SOE. People simply knew that the beans they used came from Mocha, Brazil or Colombia, and took that for granted.

It was not until later, when the consumer market reached a certain scale and wars created material scarcity, that the supply of some beans became a problem. People were forced to look for substitutes, and Robusta was the popular "substitute" of the day. Under deep roasting, Robusta's bitterness is quite aggressive, and clearly not everyone could accept it. So people hit on a good idea: blending coffee beans.

By adding some Arabica, they could dilute Robusta's taste and also reduce the proportion and importance of Arabica usage. Because the approach was very practical, it spread quickly, and over time blended beans gained popularity.

Even in an era of abundant materials, the practice of blending never stopped, because people discovered that there were simply too many benefits: besides saving cost and diluting the importance of any single bean, blending could use the strengths of each bean to cover the weaknesses of another. Most importantly, it offered extremely high stability. So to this day, blends remain the mainstay of espresso in major coffee shops.

The Rise of Specialty Coffee

It was not until Ms. Erna Knutsen proposed the concept of specialty coffee that a crack began to appear in the era when blends reigned supreme. In the article "Why Are Most Coffees Acidic Today?," FrontStreet Coffee explained in detail that for a long time beans were deep-roasted, not only because of the roasting equipment of the time but also because of uneven bean quality.

When Ms. Knutsen proposed the concept, industry leaders began improving bean quality through various means: establishing standards, spreading scientific cultivation techniques, and purchasing high-quality coffee at premium prices (such as the Red Cherry Project). These measures helped and incentivized farmers to cultivate and harvest more carefully in order to earn higher returns, and gradually bean quality began to improve.

As bean quality improved, people no longer needed extremely deep roasting to mask the negative flavors of low-quality coffee. Through experimentation they found that, without the burnt bitterness brought by deep roasting, beans could emit more charming floral and fruity aromas. From that point on, roasting became increasingly lighter. But this was limited to single-origin coffee; in the espresso world, people were still constrained by "tradition."

The SOE Revolution

This situation was not broken until 2007, when Mr. James Hoffmann brought the concept of SOE ("Single Origin Espresso") to the world coffee competition stage. At the time, most baristas were researching how to blend multiple beans into a delicious deep-roasted coffee, while Mr. Hoffmann took an unconventional approach, using a single-origin, light-roasted bean to make espresso.

Unsurprisingly, thanks to SOE's outstanding floral and fruity aromas, he won the competition. From that point on, baristas realized espresso need not be limited to certain conventions, and the concept of SOE was able to spread.

Conclusion: Why Most SOEs Are Acidic

In summary, most SOEs are acidic because they use lighter roasting, which lets more regional flavors come through. But as FrontStreet Coffee mentioned at the start, not all SOE beans use a medium-light roast; Mandailing and Brazil, for example, do not. Through years of subtle influence, people's impression is that they must be deep-roasted. Ultimately, the impression left by their deep-roasted versions is too strong, which is how the saying arose: "Only deep-roasted Mandailing is truly Mandailing." So even though light roasting might perform better, people are still willing to use deep roasting for these beans.

So why are most SOEs in cafés acidic? This brings us to another reason: giving customers more choices. Classic deep-roasted blends are an essential presence in every coffee shop. When a shop already has a deep-roasted bean, choosing another bean as SOE naturally leads people to select a medium-light roast in order to offer more variety. Choosing another deep-roasted bean would be too homogeneous.

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FrontStreet Coffee Recommendation

If you want to pull your own SOE at home, FrontStreet Coffee's espresso blends are a solid place to start, since Brazilian beans anchor them for balance and stability. Our Classic Blend combines Indonesian Mandailing, Brazilian Red Bourbon and washed Vietnamese beans into a traditional Italian-style recipe, low-acid and full-bodied with butter, roasted toast and caramel aromas and an abundance of crema; our Specialty Blend pairs Colombian washed with Brazilian semi-washed for nut, dark chocolate and caramel notes, and holds up beautifully in Americanos, lattes and flat whites.

For the single-origin espresso the article is really about, our Strawberry Candy espresso blend combines beans from Colombia, Costa Rica and Ethiopia across washed, natural and honey processes, staying low in bitterness with just a touch of acidity and bringing rose, grape, dried blueberry, sweet orange and fruit-candy flavors to both Americanos and lattes. And if you want to go all the way to single origin, FrontStreet Coffee's Genlana Estate Geisha SOE, roasted medium, carries Geisha's signature floral-fruit character and ripe dried-fruit sweetness alongside Ethiopian white florals and bright lemon acidity; pulled as espresso it turns to apricot, caramel and nuts.