You don’t have to be a barista to pull a great espresso shot at home, but you do need to know all about crema.
If you don’t want your home-made coffee to come out bitter or flavourless, it’s important to know what makes this foamy substance at the top of an espresso shot.
This article will walk you through everything you need to know about crema, including what it is and how you can optimise your brewing process for it.
What is coffee crema?
Crema is the foamy substance that floats on top of a freshly pulled shot of espresso.
It can range in colour from light tan to brown, depending on the roast of the beans and how long the shot was pulled for.
A good crema not only tastes great but also indicates that all components in the brewing process were working correctly during extraction.
The presence of crema indicates that the coffee was ground correctly (not too coarse or too fine), that the espresso machine was properly maintained and that the barista knew what they were doing when preparing the shot (e.g. proper tamping).
How does it form?
Crema is formed during the process of espresso extraction, as water is forced through tightly packed coffee grounds at high pressure.
The pressure forces carbon dioxide out of the coffee grounds, which combines with the oils in the coffee to form tiny air bubbles.
These bubbles form a thick, golden brown layer that floats on top of the darker espresso below.
Crema can’t be created without a high amount of pressure, which is why brew methods such as the Moka pot can’t achieve the same result as an espresso machine.
What does good crema look like?
Crema is an important indicator of brew quality. It should be smooth and velvety, not coarse or overly bubbly.
It should be light tan to chocolate brown in colour and have a slightly sweet taste.
Crema should have a good body and texture and be able to hold its form for at least 30 seconds (and ideally around 2 minutes) before starting to dissipate.
How much crema should you have?
The generally accepted target ratio is 1:10. So, one part crema, ten parts espresso.
This ratio allows the crema to play its role in terms of flavour and mouthfeel but won’t let it dominate the drink.
What does crema taste like?
While there’s no argument around crema being one of the signs of a good shot of espresso, there’s less agreement around whether it actually contributes to the taste of the drink.
Consumed on its own, crema tastes bitter and dry, and is often described as “ashy”.
In fact, the famous coffee expert and World Barista Champion James Hoffmann has been scraping the crema off of his espresso for years.
To get all of James’ thoughts on crema, check out his video below:
However, those in favour of retaining crema on espresso argue that it plays an important part in the flavour profile of the drink as a whole.
Its creamy texture also adds to the mouthfeel of an espresso shot, which without it feels more watery.
Pressurised filter baskets
Pressurised filter baskets, also known as double-walled baskets, can help home baristas achieve crema, even if they don’t have their grind size quite right.
Pressurized baskets create greater pressure in the basket during brewing. They feature a standard mesh bottom along with a second wall with one hole, through which the coffee extraction is forced through.
A pressurised coffee basket allows users to achieve crema on their espresso if they don’t have a precise grind size or even if they are using pre-ground coffee.
While you won’t find your barista using one of these at your local cafe, they are commonly supplied with home espresso machines such as those from Breville.
Other tips for getting more espresso crema
- Pay attention to your grind size and tamping pressure. These can both lead to over or under extraction and therefore play a role in the production of crema.
- Try using blends that contain Robusta. Coffee made with Robusta beans creates a thicker crema than Arabica beans.
- Ensure your water is at the correct brewing temperature. Water that is too cool won’t be able to produce crema.
- Dark roasted coffee has more carbon dioxide to produce crema than light roasted coffee.