IT’S ALL ABOUT THE CREMA. OR IS IT?

There is a fair amount of debate in coffee circles about the importance of crema from both an aesthetic and taste perspective, so I thought I’d add mine.


To start off, let me give you a little background information.


As coffee means come out of a roaster, they are immediately cooled, to arrest the roasting process. After cooling, the beans emit a large amount of carbon dioxide. This is called de-gassing, and is what beans cannot be packaged immediately after roasting. Personally, I aim for 24-36 hours before bagging the coffee.


The coffee beans still contain a quantity of carbon dioxide, and becomes and important component of an espresso.


I’m going to digress even further from the subject and talk about scuba diving. I’m sure you’ve all either been lucky enough to go diving or have seen movies about it. At the end of the dive, the importance of ascending slowly (always go up slower that your bubbles, was my instructor’s mantra) and doing a safety stop or stops, depending on the duration and depth of the dive. Failure to do this can result in the “bends”. This is where the nitrogen that you have inhaled whilst under pressure, forms tiny bubbles in your bloodstream, which is both painful and dangerous.


A similar thing happens when you brew an espresso. The water is forced, under pressure (about 10-12 bar), through the ground coffee. Part of what is extracted from the grounds is the carbon dioxide we spoke about earlier. As the coffee comes out the spout, the pressure suddenly drops back to normal air pressure and your coffee experiences the equivalent of the “bends”. Unlike scuba diving, its not nitrogen bubbles, but rather carbon dioxide bubbles. Also, unlike scuba diving, this is the desired outcome of the exercise!


So now we have an espresso in front of us, with a beautiful golden brown cream on top. As I’ve explained, these tiny bubbles are primarily made up of carbon dioxide. As a result, this is the most bitter part of the drink. 


Try it one day - take a teaspoon and scoop off a little crema and then a little bit of crema-free coffee. The difference is quite remarkable.


So, what do you do with this bitter crema? Some coffee lovers recommend scooping the crema off, resulting in less of the bitter notes. Others will insist that it should be stirred into the coffee to give the optimal overall taste. Personally, I love the aesthetic of a good crema, so i don’t stir mine in, but prefer to enjoy the crema along with the rest of the cup.


I hope you found this interesting.


Till next time 

Chris

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