Reason Why You Shouldn't Believe Crema

What’s Crema?
How is it Created during Extraction?
Variables in Crema Formation
Amount of Crema Isn’t a Thing

What’s Crema?

“Crema” is a term used to describe the creamy, tan-coloured foam that forms on top a shot of espresso. Originating from Italy, the word itself means “cream.” In 1938, Achille Gaggia invented espresso machines by brewing at significantly higher pressures, resulting in an unusual foam on the surface. To leverage this as a positive feature, he marketed his machines with the enticing claim of offering a ‘Natural cream coffee.’

This unique foam comprises tiny carbon dioxide bubbles coated with coffee bean oils and other fat-soluble compounds. The significance of crema lies in its ability to preserve the rich aroma of espresso. This is because the aromatic components remain trapped within the crema, enhancing the overall flavour experience of the coffee.

How is it Created during Extraction?

It is created when hot water is forced through finely-ground coffee beans at high pressure. During the extraction process, acids, sugars, oils, and various flavour compounds are extracted into the water. As both water-soluble and fat-soluble compounds are drawn out from the coffee grounds, they emulsify and eventually form the crema. This enticing layer sits atop the espresso, enhancing its aroma and flavour. However, as time passes, the gas trapped in the crema begins to evaporate, and this may impact the overall quality of the espresso.

Variables in Crema Formation

The formation of creamy layer is influenced by several variables and the amount created can be controlled by baristas. The main variables affecting the formation are:

Roast Level and Freshness: Coffee beans with the lighter roast level has much more carbon dioxide in them. When the extraction is done before the degassing process takes place, the espresso will hold much more crema. The quality of the coffee is not to be discussed this time though.

Grind Size: Since the crema primarily consists of carbon dioxide, the fineness of the coffee ground has the significant impact. Finer grounds allow the CO₂ in themselves to contact with water more easily, facilitating smoother extraction of the gas during the brewing process.

Brew Temperature: Higher brew temperature can potentially lead to more CO₂ being extracted during the initial stages of the espresso extraction process.

Extraction Time: The carbon dioxide is typically extracted early in the espresso extraction process. During the initial stages, when hot water comes into contact with the coffee grounds, the trapped CO₂ in the grounds is rapidly released. As the process continues, the gas bubbles rise to the surface and escape. With the same weight of yield, espresso with shorter extraction time may have relatively more crema than that with longer extraction.

Amount of Crema Isn’t a Thing

People often associate a rich crema with fresh and delicious coffee, but this can be a misconception. As mentioned earlier, the amount can be controlled by the barista, so it doesn’t necessarily mean it’s a delicious coffee. However, if you’re served black coffee with minimal crema, you can infer that there will be almost no aroma, whether the barista intended it or not.

While it’s possible to make some judgments based on colour, it’s important to note that the colour can vary depending on the roast level of the coffee beans. Therefore, assessing the flavour of coffee solely by its appearance can be challenging. Experienced baristas who brew the same coffee repeatedly may use the colour as a partial indicator of taste, but it’s just one of several factors that contribute to the overall coffee experience.

Conclusion

In conclusion, while crema adds charm to an espresso, it doesn’t always guarantee a perfect cup. Factors like roast level, freshness, grind size, and brewing variables influence its formation. Ultimately, coffee enjoyment depends on individual taste preferences, with or without a substantial crema. Embrace the nuances, but let your own palate determine what’s “right” for you.