what is coffee crema and why's it important for espresso

When you imagine the perfect espresso, you almost certainly picture a layer of golden crema atop your shot. Indeed, achieving a shot of espresso with the ideal crema is to some the holy grail, and considered to be a key indicator of good espresso by most baristas.

A good crema indicates your coffee is fresh, and skillfully made. And although what exactly the ideal crema should look like is a matter of debate, the fundamentals of what crema is, and the process by which it is formed are universal, and essential to understanding how to produce the ideal crema.

Even then, like most things in the world of coffee (and coffee experts), not everyone is in agreement over this delicious mouth coating foam. We wrote this article to cut through the noise: to help you understand your espresso shot better, give you a grounding in how crema is made, why it's important, and how to make better crema the barista way.

What Is The Crema On A Coffee?

The crema 'foam' on your espresso shot is quite a complex beast. Coffee beans are rich in CO2, most of which is released during roasting, and then during grinding. However, freshly ground coffee still contains gases, and the crema is a result of these gases reacting to heat and pressure when the espresso is pulled.

On exposure to hot water, and under pressure, air and CO2 try to escape the shot - but as the natural oils in the coffee emulsify, they become supersaturated with CO2 and in the process form thousands of tiny bubbles, which collectively form the foam. This combination of heat and pressure is essential - and why you can only produce real crema with espresso machines, though it's not the only factor.

Coffee begins to lose its carbon dioxide as soon as it is ground - which is why it's so important to use freshly ground coffee beans if you want beautiful crema. Freshly roasted coffee beans are also a must-have for the best flavor. Most espresso roasts consist largely of arabica beans, but robusta coffees generally contain more CO2. For this reason, robusta coffee beans are often added to espresso roasts.

Does Crema Taste Good?

Although the crema itself will likely have a very light flavour, it is widely believed that you can assess the taste of the espresso simply by looking at the crema.

So, although crema itself is probably too mild to be said to taste 'good', a good crema is a good indicator of a good, flavourful espresso.

Why Is Crema Important In Coffee?

A pronounced crema can tell you a lot about your shot of espresso. Although the lack of crema does not necessarily indicate a bad espresso, a good crema almost certainly indicates that your shot of espresso was made with the freshly ground coffee, and was pulled by a skilled barista. Despite different opinions, although you can have a good coffee without crema, you'll rarely find a bad coffee brewed with great crema.

Crema certainly adds to the character of the shot, although its influence is textural, contributing to the mouthfeel of the perfect espresso mostly. A velvety crema is the aim, so the flavor of the shot is as smooth as silk on the drinker's tongue. Many people also believe crema helps to give espresso a longer aftertaste.

How Do You Get Perfect Crema In Coffee?

As there is no consensus on what the perfect crema is, it's hard to say exactly. That said, there are a few key elements that will effect your crema which you need to get right:

Coffee Beans

Although crema can be achieved with many types of bean, you have a much better chance with mix of the dark roast arabica bean including some robusta - luckily, many espresso roasts available stick to this basic principle. Ideally, use beans which are fresh but not too fresh - roasted between 10-14 days prior to brewing.

Grind Fresh

Beans must be ground immediately before brewing with a coffee grinder. CO2 which has been trapped inside by the roasting process will begin to escape as soon as they are ground, so there is a direct correlation between the speed you get the grounds from grinder to portafilter, and the amount of crema produced.

Get The Pressure Right

The last and arguably most important aspect is pressure - which not only helps emulsify the oils, but along with the heat, releases the gases from the ground coffee and allows them to form the rich, dense crema you desire. Getting your pressure settings right for the extraction process is key to making good espresso crema. For this reason, it is generally easier to produce espresso crema using classic levered espresso machines.

Beyond this, there are many variables which will alter the nature of your crema. The coarseness of the grind can change your foam, as can over extraction and under extraction. The temperature you brew at and even atmospheric conditions can all play a part, as can the type of roast and their origin, and the espresso machine you're using. If you're thinking of upgrading your machine, first check out our round-up of the best home coffee machines.

What Does The Perfect Crema Look Like?

Well, not everyone agrees. Some prefer less crema on their coffee, some more, some favour a bubbly crema, some swear by a dark, more pronounced crema: in short, there's no one right way.

A golden colour is generally desired, but this will to an extent depend on the dark roast degree you are using. And for a good mouthfeel, a dense crema with a velvety texture is widely considered ideal, but many baristas do favour a lighter crema with a good shot of espresso.

Ideally, you only want a small amount, around a 10th of the shot - but if you prefer more, there's no reason why not. The most important thing is that you're making the crema that suits you best, so experiment and find your own ideal coffee crema.

Why Does My Coffee Have No Crema?

If you're struggling to produce crema, try changing your coffee bean type and seeing if this helps. If you are not grinding your beans fresh, definitely consider investing in a grinder.

On the other end of the scale, if you roast your own beans (or buy direct from the roaster), reducing the temperature or length of the roast may preserve more carbon dioxide and help produce more crema.

Altering the pressure settings on your machine and experimenting with the heat settings to avoid your coffee being under extracted may also help. And if you're still having no joy, it might be time to invest in an espresso machine capable of producing higher pressure for barista-quality results - we've got top of the range espresso machines available here at Alternative Brewing and a variety to suit any coffee-lover's budget. Check out our range today and get fast shipping Australia-wide!