The Science in Your Nespresso: The Crema Makes the Difference

To other newsLausanne, Switzerland,Nov 2, 2012

Coffee is more than just a beverage – drinking coffee has evolved into a savory experience. The look, the aroma, the taste and the lingering after notes. Creating the perfect coffee experience is a science in and of itself. Nestlé scientists are gathering the data behind why the crema (the smooth, hazelnut brown foam) on top of a Nespresso is an integral part of the coffee experience.

Nestlé researchers first wanted to find out how the physical structure of Nespresso foam impacts coffee aroma. In a study published in 2011 in the Journal of Agricultural and Food Chemistry, they assessed several parameters of foam structure in relation to the concentration and release of ‘above-the-cup’ aroma compounds.  

Nespresso is part of the morning ritual
Before this study, it was traditionally thought that the crema acted as a “lid,” sealing aroma compounds inside the coffee. The results, however, proved the inverse - that the crema which is formed by the Nespresso system actually supports the liberation of aroma compounds above-the-cup for the first 2.5 minutes after the espresso is made. After the initial 2.5 minutes, the crema then functions as a lid, retaining the aroma compounds inside the cup.

Following the results of this 2011 study, Nestlé scientists delved further into the understanding of Nespresso crema and aroma. In a recently published study in Food & Function, they investigated the characteristics of foam which provide optimal aroma release and in-mouth sensory attributes.

Nespresso study in Food & Function journal This study about Nespresso crema characteristics was published in the September issue of Food & Function journal

Seven Nespresso coffees with varying crema characteristics, including a coffee without crema, were compared. Trained sensory panelists confirmed that all coffees shared similar qualities (except for the crema), to ensure that the data uniquely described crema characteristics. Researchers used the seven coffees to determine the influence of crema on ‘above-the-cup’ aroma release; aroma release in the nose after the first drink of coffee; and in-mouth sensory perception during the full coffee drinking experience.

Study results revealed that the influence of espresso crema on aroma release is complex and varies throughout the coffee drinking experience.

“We confirmed that the presence of espresso crema helps release more volatile aroma compounds above-the-cup and also promotes the release of these pleasing compounds in the mouth during consumption of a Nespresso coffee,” said Dr. Denis Barron, Nestlé scientist leading in the study.

Additionally, trained sensory tasters in the study identified that a roasted flavour is dominant when there is crema on top of the espresso.

“We suggest that Nespresso crema in its standard quantity is associated with the optimum release of pleasant aroma compounds. This is an integral part of what gives espresso its alluring aromas before drinking and which provide its rich flavour from the first to the last sip,” concluded Dr. David Labbe, another Nestlé scientist involved in the study. 

Article References
Dold S, Lindinger C, Kolodziejczyk E, et al. Influence of foam structure on the release kinetics of volatiles from espresso coffee prior to consumption. J. Agric. Food Chem. 2011, 59: 11196-11203.

Barron D, Pineau N, Doret-Matthey W, et al. Impact of crema on the aroma release and the in-mouth sensory perception of espresso coffee. Food & Function, 2012. 3(9):893-986.

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