One of the most frequent questions we get is this: How do I produce more crema on my espresso shots? We decided it would be a good idea to give an overview of what crema is, and explain why you might not want more!
What is crema?
Crema is the tan liquid that forms when you’re first pulling your espresso shot. As the shot pulls, the liquid gets darker, and you end up with a layer of this tan colored head on top of the drink. This gives it the look of a well poured stout beer. But where does it come from? In part, crema is created when water is pushed through the coffee at pressure. This emulsifies the oil in the coffee and forms tiny bubbles of air. Brighter liquid is also formed by C02 emissions during the extraction, though this isn’t quite the same thing as the crema from the fat in the coffee. That C02 is present in the bean after roasting, and naturally defuses through a process called “out-gassing.” Fun fact, the valve on your bags of coffee exists specifically to facilitate this out-gassing process.
But what does it really taste like? Sour, it turns out! While certain roasts benefit from a layer of crema to balance out the flavors of the espresso, in other roasts limiting crema is actually preferable. In fact, some roasts don’t even produce any crema due to low fat content. So what factors actually influence this sour layer of bubbles?
How to get more (or less) crema
The first thing to note is processing. Natural/honey process roasts retain more of the bean’s fat content. As noted above, a fattier bean will result in more crema. This is part of why it can be hard to dial in a natural, and why espresso blends are so popular. Ultimately, climate also has a lot to do with the oil content of the beans as well, so the whole production process influences the fat levels in the roast. Another thing to consider is roast date. It’s tough to call out the ideal time to brew and espresso after roasting. However, you’ll definitely see more of the brighter liquid during the first 72 hours after roasting. Generally the coffee will take this long to de-gas as described above. This is why it’s usually advisable to wait a few days after roasting before attempting to dial in fresh beans.
Another factor in crema formation is roast level. Darker roasts pull the oils in the coffee to the surface of the bean, this actually results in
less crema. This is because there is less oil in the bean after grinding and transferring to a portafilter. Finally, equipment matters too. a pressurized portafilter will naturally result in higher pressures, which will create more crema. That said, it won’t be as rich as crema created through more natural, unpressurized means.
In any case, it’s important to remember the point above: While crema looks nice, you should work to pull a good shot, not one that is loaded with crema. This will create a more sour shot, rather than a balanced one!
