Is the Golden Foam of Espresso Actually Coffee Oils or Crema? Are Thicker Oils Better?

Recently, in the article "Why do people still like espresso when the crema is so bitter?", FrontStreet Coffee shared that this layer of golden foam extracted by espresso machines is called Crema. This led some friends to ask in the comments: is it Crema or "oils"?

We can first look at this full picture of espresso, which is mainly divided into two parts: the coffee liquid and the golden foam floating on the surface.

The Origin of the Term "Crema"

When espresso machines were first invented, this foam was the main substance that distinguished espresso machines from other coffee makers. Only the high pressure of an espresso machine could produce coffee with this layer of golden foam. So people needed to give it a completely new name to distinguish it from other coffees. Because this foam was quite thick when first extracted and had a certain smoothness, looking very much like thick cream about to be whipped, people gave it this name: Crema, which means "cream" in Spanish.

Why Crema Came to Be Called "Oils"

However, when espresso was introduced to new markets, cultural differences led people to misunderstand its meaning. Many assumed that Crema referred to a cream-like, oily substance, so through a series of misunderstandings, the foam mistakenly came to be called "oils." Although the word "oils" is not quite accurate, it has become deeply ingrained in people's minds. To keep many beginners from not understanding what Crema is, FrontStreet Coffee sometimes continues to use "oils" to refer to this foam.

Is More Crema Always Better?

So, is more crema always better? In a previous article, FrontStreet Coffee mentioned that the presence of crema gives espresso a richer aroma, a thicker mouthfeel, and a longer aftertaste. Therefore, many friends might think that a coffee with more crema must be more delicious.

But that is not actually the case. The quantity of crema cannot be used to measure the taste of espresso, because it only serves as an enhancement, for example adding more layers. The taste of the espresso itself remains what it is and is not affected by the crema. After all, there are many ways to increase the amount of crema, such as:

Deeper Roast Level

The roast level of coffee beans affects the thickness of the extracted crema. When the roast level is deeper, the structure of the coffee beans becomes looser, making it easier to extract the carbon dioxide contained within during extraction and thus forming rich crema.

Bean Freshness

Carbon dioxide gradually escapes from the beans over time, so if we want rich crema, we cannot choose beans that have been stored for too long (from two months after the roast date) for extraction, because the carbon dioxide has already been significantly lost. In terms of bean freshness, it is best to choose fresh beans from the 5th day to 2 months after roasting, as this will yield a large amount of crema, because this is when the beans have the highest carbon dioxide content.

Bean Variety

The reason we do not choose freshly roasted beans is that they bring a negative effect: too fresh, too much gas. Although the extracted crema quantity is high, it will be quite rough, dissipate quickly, and have a dry feeling when consumed. On bean variety: Arabica is the main variety we use daily, but if we are not pursuing taste but the amount of crema, we might as well switch to Robusta beans at the same roast level, which will extract more abundant crema.

The main reason for this difference is the different lipid content between varieties. Arabica coffee beans have about 14%-18% lipid content, while Robusta coffee beans have about 9%-12%. Although Robusta appears to have less lipid content than Arabica, in fact more lipids hinder the formation of this layer of crema. So Robusta, with its lower lipid content, can extract richer crema — but as for the taste, well, you can imagine.

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FrontStreet Coffee Recommendation

If you want crema that both looks generous and tastes good, the blend behind your shot matters. For traditional Italian-style Americano and latte, choose FrontStreet Classic Blend or FrontStreet Commercial Blend. Both add a small amount of Robusta on top of an heirloom Italian recipe, which not only provides more golden foam but also instantly lifts the creaminess and caramel aroma, with extraction yielding butter, nut, spice, dark chocolate, and toast notes and a bold, thick body.

If you care more about the espresso's sweetness and balance than sheer crema, FrontStreet Specialty Blend and FrontStreet Black Cocoa Blend are the first choices, since both contain a large proportion of Brazilian coffee and give a comfortable bittersweetness, a creamy peanut aroma, and a very smooth entry. FrontStreet Specialty Blend adds the nutty, chocolate, and caramel notes and moderate acidity of Colombian coffee, while FrontStreet Black Cocoa Blend combines the ripe plum acidity of Yunnan small-bean coffee with a cream chocolate aroma when ground, staying balanced and highly adaptable for both shops and homes.

For SOE drinkers, variety and processing shape the cup. FrontStreet Sun-Dried Huakui SOE shows a creamy strawberry flavor thanks to its terroir and natural processing, grown in Guji, Hambela at altitudes up to 2,300 meters, and after a medium roast it brings cream, cocoa, berries, light florals, and black tea to an Americano or latte. FrontStreet Costa Rica Blackberry SOE, a honey-processed single origin, captures the blackberry aroma and clean sweetness of the fruit pulp: bright and refreshing as an Americano, and showing cranberry cookie, raisin, and nuts with milk. FrontStreet Brazil Queen's Estate SOE, a yellow bourbon with a gentle, sweet profile, is roasted medium-dark and pulls into butter cookie, macadamia, and toast creaminess under an espresso machine.