The Froth On Top Of Espresso : EXPLAINED

Do you ever wonder how the foam on top of your espresso cup is formed?

For those who don't know, the foam that sits on top of your espresso has a lot to do with how good it tastes and how much foam there is. Generally, this process is called "crema" and is formed during coffee extraction, where boiled water permeates the coffee grinds.

The science behind it:

When coffee beans are being roasted, carbon dioxide (CO2) is formed and trapped inside the beans. During the extraction phase, when hot pressurized water permeates the ground coffee, it reacts with the CO2 and dissolves it.

Then, when the brewed liquid is on its way to the cup, it returns to the normal atmospheric pressure, allowing the CO2 to come out of the solution as countless tiny bubbles. These bubbles then are trapped together and appear as a stable foam on top of the espresso cup.

Factors that influence the crema:

1. The pump pressure of the machine, along with the temperature of the pumped water, play a significant role in the crema formation; Ideal water temperature is Between 195-205ºF, and the ideal pump pressure is 9-12 bars
2. Crema formation, flavor, and sweetness depend a lot on the type of beans used in your espresso
3. Freshly roasted beans form better crema than old beans since CO2 can be lost over time

Does the froth on top of the espresso mean something?

A frequently asked question is the foam on top of the espresso a sign of a good espresso? Generally, the appearance of crema means that the espresso has been brewed well, which most people consider a good quality, but in reality, you can still have a perfect cup of espresso with little to no crema on top of it.

Now that you know what crema is, I think it's time for you to get your hands on Eighth Brew's Portable Coffee Machine and test it out, be ready to get shocked with the quality of the espresso Eighth Brew will give you!