What Is Espresso Crema and How To Make It Perfectly Every-time
Before I started with my coffee obsession, I was just another come-what-may coffee drinker.
Until I forayed into this circle of coffee friends, who talked about terms like espresso and crema, and how it mattered greatly with our favorite brew.
But what is espresso crema and how can we master it?
In a Nutshell - What is Espresso Crema?
Espresso is a word you may have heard plenty of times in your favorite coffee shop, and perhaps have always thought it only meant ‘a small amount of coffee’.
Well, while this is partly true, there is more to the word than just its ‘size’.
The word espresso pertains to a method of brewing that produces around 1 to 2 ounces of coffee, achieved by combining pressure, nearly boiling water (190°-200°F), and finely ground, compacted beans.
The process of brewing an espresso shot takes about 25 to 30 seconds.
Crema is often mentioned with reverence in relation to espresso. It refers to the light-colored layer that forms on the surface of brewed coffee during the extraction stage.
The Science Behind The Elusive Crema
Now that we know how these two words relate to each other, it’s time to find out the food science behind espresso crema that will help explain its significance in the overall coffee experience.
Espresso crema, carbon dioxide, and coffee oils
Roasted beans are ‘fresh’ when they still generate or emit a high concentration of CO2 or carbon dioxide.
The process of grinding beans further releases this element, and it is what later interacts with other elements in the brewing process.
With espresso brewing, carbon dioxide coming off the compacted fresh grounds meeting with hot, pressurized water cause the trademark ‘bubbles’ to form.
The phenomenon is quite similar to what happens when you pour a bottle of Guinness beer.
While espresso crema may look a lot like the foam you see when your soda bubbles up, a closer look will show you the big difference.
The bubbles are finer, and often crema can even be thick enough to support a spoonful of sugar.
What makes espresso crema’s different and essential to a great cup of espresso, is that it is also largely a result of emulsification of natural oils, sugars, and compounds like melanoidin found in abundance in fresh coffee grounds.
This is another reason why the formation of crema is often looked at as a good sign of a possibly delicious cup of espresso.
What Does the Color and Amount of Crema Tell You?
Have you ever wondered why some drinks have such light-colored crema and others have a darker ring?
Or why others have so much and some have too little?
These slight differences show either the kind of roast used, how long the espresso shot was, or a possible problem with the consistency of your coffee grounds.
If the color is too light and the bubbles are larger than usual, then you may have under-extracted your espresso.
You may want to give that stage in the process a few more seconds, as your resulting brew will most likely taste weak and thinner in consistency.
A darker crema on the other hand can either be a result of over-extraction, or the use of a darker roast (which also usually produces less crema). Over-extracted coffee can result in a bitter cup.
Another aspect that may affect the production and color of crema is the kind of processing the roasts went through.
Dry processed beans leave more natural coffee oils intact compared to wet-processed beans, allowing the former to produce more crema.
How do you Make Espresso Crema?
Crema is ideally, naturally produced when you make a great shot of espresso out of dry processed, freshly roasted beans. So to get a good crema, you start with making a good espresso.
Here are the basic steps:
- Choose your freshly roasted beans. You would want to have them to a fine ground, to ensure that they are sufficiently compacted when you put them in your espresso machine’s portafilter.
- You place your ground coffee into the portafilter and pack it in using a tool called a tamper. The tamper is a specialized tool that helps ensure that your coffee is horizontally leveled and tightly packed - you need to apply about thirty pounds of pressure on it.
- What you’re aiming for is a cake-like layer of coffee, where the jet of hot water from your machine can stream through with a pressure of nine or more atmospheres. Brew temperature should be about 200 degrees.
- The brew time of your espresso to enforce the ideal extraction time is about 25 to 35 seconds at most. Crema should form in a few seconds after the brewing process.
This video shows how to make your espresso correctly, to get that beautiful layer of crema on top of your steaming hot cup of coffee.
Experiencing the ‘legendary’ espresso crema is one of those ‘musts’ for a coffee enthusiast.
Now that you know the chemistry behind it, I’m sure you’ll appreciate its presence more, and understand why you can’t find it in some of your coffee drinks.
Here’s a quick summary of what espresso crema is all about:
- It’s a good gauge of the freshness of your roasted coffee beans.
- It’s tell-tale of the kind of roast used (light or dark).
- It enhances your coffee experience, if done or made right.
- It doesn’t always mean that your coffee is going to taste great.
Coffee is a lot about science and chemistry so let’s continue learning about it!
Have your own thoughts about crema? Share em’ in the comments below!