What is Coffee Crema?

It's all about pressure. When hot water gets forced through the finely ground coffee at high pressure – around nine bars, give or take – it makes the coffee oils, and the water mix up properly. This whole process releases carbon dioxide, which then creates all those tiny bubbles. Those bubbles rise to the top, and that's your crema.

A good crema should be a rich, tawny colour and have a fine, even texture. You'll want it to be thick enough to hold a bit of sugar for a few seconds, too.

The colour and texture of your crema can tell you a fair bit about how well your espresso's been made. Here’s what to look for:

• Reddish-Brown Crema: The Sign of Freshness: If your crema has a reddish-brown hue, that’s a good sign as it usually means your coffee beans are freshly roasted, which is key to a vibrant espresso.
• Golden-Brown Crema: The Ideal Balance: A golden-brown colour is the sweet spot. It’s a sign of an ideally balanced extraction. Exactly what you want to see before you sip your espresso.
• Light-Coloured Crema: Potential Under-Extraction: A light-coloured crema could be a sign of an under-extracted coffee. This could be due to the water not applying enough pressure to the coffee beans and therefore not absorbing enough of the oils to provide you with a delicious espresso.
• Dark, Thin Crema: Over-Extraction or Stale Beans: On the flip side, a dark, thin crema might suggest over-extraction, where the water lingered a tad too long. Or it could be a sign that you used an old batch of coffee beans, which could be dried out and crackly, leading to a bitter brew.

No, you won’t find crema on every cup of coffee. It's a unique feature of an espresso. It’s the high-pressure brewing that forces hot water through finely ground coffee that creates it. Other methods like drip, French press, or pour-over, using gravity or immersion, don't generate the necessary emulsion and carbon dioxide release.

Crema formation is affected by a few things: fresh beans (for oils and carbon dioxide), fine grind (for optimal extraction), and crucially, high brewing pressure. Without the correct amount of pressure, crema won't form.

Crema, though often mixed with milk in drinks like cappuccinos and lattes, significantly impacts their flavour. It carries the espresso's aromatic oils and bitter notes, preventing the drink from becoming overly sweet or bland.

In a cappuccino, crema balances the milk's sweetness, contributing to a richer, more complex taste.

In a latte, the crema allows the espresso's inherent flavours to cut through the milk's creaminess.

A robust crema in the initial espresso shot indicates these qualities will persist throughout the coffee, enhancing the overall drinking experience.

There can be multiple issues that can occur when trying to achieve the perfect crema. We list these below along with solutions.

Thin, fleeting crema usually indicates a problem with extraction.

• Adjust your grinder to a finer setting. A coarser grind allows water to flow through too quickly, resulting in under-extraction and a thin crema.
• Check the freshness of your beans. Stale beans have lost much of their essential oils and CO2, which are crucial for crema formation

No crema at all often points to insufficient pressure or stale beans

• Make sure your espresso machine is operating at the correct pressure. Check your machine's manual for maintenance instructions.
• As above, older beans will not produce crema, so ensure you are using freshly roasted, high-quality beans.

Uneven or patchy crema can suggest inconsistent tamping or uneven grind distribution

• Practice a consistent tamping technique. Apply even pressure to ensure uniform extraction.
• Ensure your grind is evenly distributed before tamping. A clumpy grind can lead to uneven extraction.
• Check the calibration of your grinder, to ensure the grind is consistent.

Traditional espresso machines can be a tad tricky; you have to get the pressure just right. But with a NESCAFÉ® Dolce Gusto® coffee machine, our pods do all the work. They're pre-filled with the perfect grind, and our machines use the ideal pressure, meaning you get consistent crema every time, without any fuss.