What is Crema? Where does it come from? What if there isn't any on my espresso? Find out everything about that elusive foam here.
Crema is what sets espresso apart from the rest. It’s that beautiful, rich, creamy foam that sits atop your espresso. For many, it’s a great visual indicator of quality: classically, a properly prepared espresso should have a thick layer of crema on top of which a teaspoon of sugar should float for a few seconds before sinking down into the depths of the espresso. It’s also a great sign of freshness. Crema dissipates within a few minutes, so it's a sure sign that your espresso wasn’t sitting around for ages before making it your table.
But crema is not the end of the story. An espresso with a thick, creamy layer of crema can still taste terrible, just as a delicious espresso needn’t be topped with this red-brown foam.
What produces crema?
Crema is a product of the CO2 trapped in coffee during roasting. When you brew that coffee under pressure, CO2 is released in great quantities and dissolved in the water. As the espresso then flows out of the porta filter, the pressure decreases and the CO2 comes out of solution, creating a foam. Its effectively the same process as when you open a bottle of soft drink and it fizzes up.
The amount of crema is therefore dependant on how the coffee was roasted, and how it was brewed. Lighter roasted coffees contain less CO2 and therefore produce less crema. Moreover, lighter roasted coffees need to be brewed at higher extractions to reach their full flavour potential, which also produces less crema. A lot of our single origin espressos are roasted in this style, so don’t be disheartened if they don’t have that rich crema you remember from your last Italian holiday – we promise they’ll still be tasty.
Another factor is age: the older the beans, the more CO2 has naturally dissipated, and therefore the less crema you’ll get. In this case, the lack of crema shows a lower quality.
Crema: good or bad?
It’s impossible to say from crema alone whether an espresso is good or not. In fact, some people like to scoop off the crema from their espressos, reasoning that a lot of the fine particles, oils and other nasties are suspended in the foam, and that removing it gives a cleaner espresso! Try it for yourself next time and see where you stand on crema.