Espresso Layers – Crema, Body, Heart Explained

It doesn’t matter if you are a barista, home brewer, or a regular coffee drinker, you absolutely must know about the espresso layers. 

To an untrained eye, the espresso layers meant nothing. However, little did you know that looking at a freshly brewed espresso, it can tell you the quality of the coffee beans, the freshness of the coffee beans, the flavors to expect, and the skill of your barista. 

All these without even tasting the espresso! Does that sound cool to you already?

In this post, I am going to deep dive into the layers that make up an espresso and the characteristics of a good espresso.

What Is An Espresso Shot?

The basic espresso shot is the foundational building block in the basics of coffee. Hence, before we enter the discussion about espresso layers, let me bring you on a short educational tour around espresso. 

Did you know that the word espresso traditionally does not refer to the drink itself, instead espresso is actually a brewing method of Italian origin. The word espresso quite literally means “express” which describes the coffee scene back then in Milan, Italy. Busy workers will often stop by coffee shops for a quick “grab and go” espresso to fuel them for the rest of the day.

In the modern day, an espresso shot is a concentrated form of coffee made by forcing pressurized water through fine coffee grounds to extract a golden syrupy liquid known as espresso. You can enjoy espresso as it is or it can be a base of a myriad of espresso drinks. 

Of course, there are other ways to brew espresso without the use of an espresso machine but only espresso machines produce true classic espresso.  

3 Layers Of An Espresso

If you jump onto the Internet and look up “espresso”, there are many recipe variations on how to prepare an espresso. But, all of these espressos will have one thing in common; which is the 3 parts of the espresso shot that characterize an espresso.

The three layers that define the character of espresso are:

Each of these layers carries its own attributes and plays a part in the overall tasting experience of espresso. Let us dive into the details of each of the layers of espresso and how they affect the taste of the espresso itself.

1. Crema

Sitting directly on top of the espresso is the first layer known as the crema. Visually, the crema is a fine layer of froth with a golden brown hue resembling the foamy aesthetics of a well-poured Guinness beer. 

Fun fact! In the early days, the crema was known as coffee scum and was usually discarded. Today, we use it as a telltale sign of fresh coffee!

The process of formation of crema is a relatively simple chemical process and I will simplify it into three simple steps.

So, if you are using old coffee, CO₂ would have seeped out of the coffee beans and the emulsification process cannot trap any of the gasses to form the crema.

Although the crema is visually pleasing, this layer is actually the most bitter part of the espresso. This is why some espresso aficionados prefer to skim off the crema before enjoying the espresso. Others would argue that the crema is essential to balance up the flavor of the espresso.

At the end of the day, it all comes down to personal preference and there is no right or wrong way to enjoy an espresso. But I have to say, coffee with crema layer simply looks aesthetically pleasing!

2. Body

The second espresso layer is the “body” of the espresso shot sandwiched between the crema and the heart. This part of the espresso has the highest contribution to the overall tasting notes of the espresso. This is because the “body” of the espresso is where most of the complex acids and flavor compounds are.  

You can generally categorize these complex acid and flavor compounds into three classes:

• Soluble Solids

Soluble solids are simply dissolved soluble compounds in your espresso which are extracted from the coffee grounds. These compounds are responsible for the taste of the espresso. You can check the concentration of these soluble compounds in your coffee by using a refractometer which is usually measured as Total Dissolved Solids (TDS). 

• Soluble Gasses

Soluble gasses on the other hand are gasses that are extracted from the coffee grounds along with the liquid. These soluble gasses are responsible for the aroma of the coffee when you brew coffee! 

• Insoluble Solids

Lastly, insoluble solids are a mixture of coffee oils and fragments of coffee fiber suspended or emulsified in the espresso. The coffee oil is the portion that contributes to the aroma, taste, and flavor of the espresso while the fragments of coffee fiber give the espresso the mouthfeel sensation.

And hence, the “body” of the coffee is where you can generally taste the unique acidity and sweetness of the coffee. 

Author’s Note: The acidity and sourness of coffee is a common misconception especially when it comes to specialty coffee. Simply put, acidity is bright and pleasant to your taste buds while sourness is overwhelming and unpleasant. 

3. Heart

Resting at the bottom of the espresso is the “heart” of the espresso. This part of the espresso is the very first bit that is extracted from the coffee grounds. 

Physically, the “heart” of the espresso has a thick and viscous consistency and it has a deep rich brown color. This dark liquid defines the flavor intensity of the espresso, staying true to its name. Tasting the “heart” will give the same sensation of having melted dark chocolate coating your tongue. It is intense, dense, and has bits of solid coffee grounds.

Also, tasting the “heart” of the espresso alone will give your palate a punch as it has the highest acidity. Hence, this is why espresso drinkers usually stir and mix the espresso layers to balance up the bitterness, acidity, and sweetness.

Espresso is a small but truly complex drink. 

Tasting Different Espresso Layers Independently: Salami Shot Technique

So, I have been describing what each of the individual layers of espresso tastes like along with its consistency and mouthfeel.

Now, you might be wondering how you split up the espresso shot when it is flowing continuously out of the espresso machine.

The answer is using the Salami Shot Technique. 

All credit to Chris Baca who coined the slang term and he has graciously made a video summarizing this technique. 

To simply summarize what are the expected flavors from each distinct layer, I’ve put together an illustration of the Salami Shot Technique. 

How To Pull The Perfect Espresso Shot?

Understanding the different layers of the espresso is important but pulling the perfect espresso shot is equally important. You can’t really taste good espresso if you can’t get the perfect espresso shot. 

And so, here are 7 tips to help you get the perfect espresso shot.

1. Yield Ratio

Brewing espresso isn’t simply just forcing pressurized water through coffee grounds. Like all beverages, there is a recipe that acts as a guideline, and espresso is no different. In this context, we look at the factor called the yield ratio.

Simply put, it is the ratio of coffee grounds to the amount of espresso liquid you should get. Traditionally, the ratio is measured using volume where 17-18 grams of coffee grounds should yield roughly 60 ml of espresso. However, as the topmost espresso layer (crema) may vary from each brew due to the coffee’s freshness, this doesn’t seem to be accurate.

Hence, we use the mass of the espresso liquid. The yield ratio that we typically look at for a decent espresso shot is 1:2. So with 17-18 grams of coffee grounds, you should aim to get 34-36 grams of espresso.

That said, these ratios are not set in stone, so feel free to tweak these numbers to see what works best for you.

2. Choose The Right Grind Size

To pull the perfect espresso shot, you need to get the grind size of the coffee bean right. 

If you grind too fine? The water will find it challenging to penetrate the bed of coffee in your portafilter. This leads to an under-extraction of your coffee grounds.

Or If you grind too coarse? There will not be enough resistance from the coffee puck and water will simply just gush through your portafilter. This leads to over-extraction of your coffee grounds.

Both of these will not yield you any distinct espresso layers.

Barista tip! Be patient and slowly adjust your grinder one click at a time until you achieve the right flow rate.

3. Use Fresh Coffee Beans

I cannot stress the importance of using fresh coffee beans. Old coffee beans tend to go rancid and the flavors of the coffee beans would have degraded over time. Furthermore, the aromatics that characterize the coffee bean will slowly seep out if left out for far too long. 

The flavor of the espresso will be flat, bitter, and uninteresting.

You simply cannot expect great quality espresso with bad coffee beans. So once again, get fresh coffee beans from your local roastery!

Author’s Note: Other than using fresh coffee beans, I would also highly recommend getting whole coffee beans instead of ground coffee as whole coffee beans retain flavor and aroma comparatively better. 

4. Espresso Tamping Pressure

Espresso tamping has always been and is still a hot topic to debate. Coffee aficionado argues that you will only need to lightly compact and level the top while the rest may argue to apply a certain amount of pressure on the coffee grounds. 

Personally, I would tamp with a force just enough to feel that the coffee puck is nicely packed. Plus, Socratic Coffee published research showing that tamping pressure does little to affect the final taste of the espresso.

So, if you are new to espresso brewing, here’s a tip to help you familiarize yourself with the tamping pressure. Simply press your tamp on a weighing scale to see how much force you need to exert to achieve roughly 20 pounds to 30 pounds. 

With experience, tamping espresso with adequate force will soon be second nature.

5. Remove Coffee Clumps

At times when your coffee grounds slide out of your grinder, you will notice that the coffee grounds tend to clump together. This is not conducive for espresso extraction as these clumps of coffee will cause uneven coffee distribution when you tamp your coffee.

As a result, some parts of the espresso puck will be denser than other areas. This creates easier pathways for the water to navigate through the coffee ground and this is when channeling happens. 

Your espresso will be unbalanced in terms of flavor and taste watery.

Barista Tip! Coffee clumps may sometimes be caused by static during coffee grinding. A simple way to reduce static is to give your coffee beans a spray or two with a mist of water. 

6. Extraction Time

You can run your espresso machine for a while to extract your coffee grounds but you will not get an espresso. Instead, what you get is a lungo; a watered-down espresso with higher bitterness. Safe to say, this is not what we want in an espresso.

To brew espresso, the extraction time is important to prevent you from over-extracting or under-extracting the coffee. Ideally, a single espresso shot takes around 25 to 35 seconds to brew. Feel free to play around and see which time gives you the sweetest cup. 

However, you should not use this factor alone to judge your espresso extraction; you should also be wary about the yield ratio and extraction pressure at the same time.

7. Extraction Pressure

The extraction pressure is a good indication of how well you extract the espresso. On every espresso machine, there will be a pressure indicator to show the pressure at the espresso machine group head.

Ideally, you will want your pressure indicator to hover around 7 to 9 bars to achieve that perfect espresso shot you are looking for. Any lower will net you a watery espresso while going higher will result in droplets of espresso liquid. Neither of these will give you the espresso layers you are looking for. 

FAQ On The Espresso Layers

What are the layers of espresso?

The two distinct layers of espresso are the crema (light brown, on the top) and liquid (dark brown, on the bottom). The top foamy layer which is the crema is a

 The crema layer is made up of bubbles of CO2 that have been surrounded by water and oils, and usually contains suspended coffee fragments and emulsified oils.

What is the foam on espresso called?

The foam on espresso is called crema. The crema has a golden brown hue and forms its own distinct layer on top of the espresso.  It is formed as high-pressure water emulsifies the coffee oils trapping CO₂ bubbles during espresso brewing. In terms of flavor, the crema is the most bitter.

Why is there no crema on my espresso?

The most probable reason why there is no crema on your espresso is you’re using the wrong coffee grind size to pack your espresso filter. Without enough resistance, water can easily penetrate through your coffee puck in the portafilter. The other possible reason is that your coffee is not fresh anymore. 

What is a dead espresso shot?

A dead espresso shot is when espresso is left out in the open for far too long. Hence, espresso should be drunk almost immediately after brewing, after which it rapidly starts to deteriorate up until a point where it is undrinkable and deemed dead. A cold espresso will taste very acidic. 

Conclusion

Now that you have understood the espresso layers, it’s time to head out to your favorite cafe and appreciate the espresso even more! Or perhaps check if the espresso you brew before this has these distinct layers that make up a good espresso.

If not, you may have to do some troubleshooting to see why your espresso is not showing these layers. Baristas and homebrewers alike have been spending most of their time pursuing the perfect espresso shot so much that the term “Godshot” was introduced. 

But that is a story for another article. 

If you find this piece of article informational, please do share it with your fellow friends, baristas, and home brewers! 

Happy brewing!