The golden-brown, velvety layer that sits atop a perfectly pulled espresso shot is known as crema. It is the visual signature of a well-extracted shot and a key indicator of freshness and quality. While many factors contribute to crema, the coffee bean itself plays the most critical role, and in this regard, Robusta is the undisputed champion.
Itadi Coffee’s Specialty Robusta is the secret ingredient that provides the stable, rich crema that is the hallmark of traditional Italian espresso.
What is Crema, Scientifically?
Crema is not just foam; it is a complex emulsion created during the high-pressure extraction of espresso [1]. It is primarily composed of three elements:
1.Carbon Dioxide (CO2): Gas trapped inside the bean during the roasting process. The high pressure of the espresso machine forces this gas out, where it forms bubbles.
2.Coffee Oils (Lipids): Fats and oils extracted from the coffee bean. These oils stabilize the CO2 bubbles, preventing them from dissipating quickly.
3.Proteins and Melanoidins: These compounds contribute to the color, texture, and stability of the crema.
Robusta's Role: The Crema Catalyst
Robusta beans are naturally superior at producing crema due to their unique composition:
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Component
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Robusta Content
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Arabica Content
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Impact on Crema
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Lipids (Oils)
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Lower overall, but with different composition
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Higher overall
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Robusta's specific lipid composition is more effective at stabilizing the emulsion.
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Proteins
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Higher
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Lower
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Proteins are excellent surfactants, helping to trap and stabilize the CO2 bubbles, leading to a thicker, more persistent crema.
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Density & CO2
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Higher Density
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Lower Density
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Robusta's denser structure traps more CO2 during roasting, resulting in a more vigorous release and a richer layer of crema.
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The result is a crema that is thicker, darker, and more persistent than a shot pulled with 100% Arabica. This is why most high-quality espresso blends contain a percentage of Robusta—to guarantee that beautiful, tiger-striped crema.
The Itadi Advantage: Quality Crema
The challenge with low-grade Robusta is that while it produces crema, it often comes with a harsh, burnt flavor. Itadi Coffee’s Specialty Robusta solves this problem.
•Clean Flavor: Our meticulous farming and processing in Togo ensure that the high-crema potential of the Robusta bean is delivered without any off-flavors.
•Stability: The high-quality proteins and oils in our beans create a stable crema that lasts longer, preserving the temperature and flavor of the espresso underneath.
The next time you pull an espresso shot, appreciate the golden layer of crema. It is a testament to the science of high-pressure extraction and the unique, powerful properties of the Robusta bean. By choosing Itadi Coffee, you are choosing the traditional, world-class foundation for the perfect espresso shot.
References:
•[1] Food Chemistry – Research on the chemical composition and stability of espresso crema.
•[2] The Physics of Coffee – Scientific analysis of the espresso extraction process.
•[3] Itadi Coffee Espresso Guide – Recommendations for achieving optimal crema.