Crema or Not, Here I Come 🤦‍♂️
At a recent cupping at the 1 Hotel in Hanalei, a customer asked me to describe exactly what crema was, and I realized my thoughts weren’t organized well. So this post is an attempt to tidy them up.
 
So, What Is Crema?
Crema is the creamy, caramel-colored foam that sits on top of a freshly brewed espresso shot. When hot, pressurized water is forced through finely ground coffee, it extracts gaseous CO₂, coffee oils, and liquid coffee. The CO₂ microbubbles combine with the coffee oils, creating the crema. Since this emulsified layer is filled with CO₂ bubbles, it rises to the top of the espresso.
 
That is crema—coffee oil with tiny CO₂ bubbles.
 
What Crema Tells You About Your Espresso
When I’m running around assisting baristas with their dial-in process, we obsess over the flow rates of an espresso shot: too long, and it’s watery; too short, and it’s sour; hit the sweet spot, and it’s epic. Another major cue in the espresso dial-in process is crema. A quick look at a finished espresso shot can tell you a lot.
 
From the moment the coffee roasting process is finished, roasted coffee slowly releases CO₂ from the beans. The fresher the coffee, the more CO₂ is embedded in the beans; the longer it’s been sitting, the less CO₂ is left. So, if you pull a shot of espresso and it comes out of your portafilter at a nice, slow speed but produces no crema, your first port of call should be to check the roast date.  Low crema can mean stale coffee. It can also indicate low pressure on the machine or a grind size that’s too coarse. Typically, though, it’s a giant red flag that your beans are too old.
 
Does Crema Affect the Taste?
Yes. If you separated out the crema from the rest of the coffee, you’d notice that the crema is bitter due to the concentration of CO₂ and smooth and velvety due to the oils and bubbles. Conversely, the rest of the coffee presents the acids, sugars, and general flavor profile of the beans, similar to a more intense version of a pour-over.
Full-blown coffee nerds will often let the espresso shot cool slightly, then stir in the crema to balance the sweetness of the coffee with the bitterness of the crema.
 
Summary poem that came to mind for this post: 

If to be perfectly happy, you need to be a little sad.  Then, to be perfectly good, you need to be a little bad.
January 27, 2025 — Tom Denton