Both of these items must be of a very high quality in order for the drink to be perfect. A perfect espresso coffee is made with high quality coffee beans and water. The two most important things for making a great tasting espresso are using high quality coffee beans and water.
The quality of the coffee beans you use has a key role in how well your espresso machine works.
The following paragraphs explain how the use of oily coffee beans can not only alter coffee taste, but also affect how your coffee machine works.
Coffee roasts
There is no one type of coffee bean that can only be used to make espresso. They are only coffee beans. What distinguishes coffee beans is their roast. Roasted coffee beans can range from light to dark.
Technically, any bean can be used to make espresso. Espresso is a brewing method, not a type of bean.
In order to create an authentic espresso, the beans must be roasted to a medium-dark color. A rich, velvety crema is what we consider an espresso to be complete with.
The problem is that many coffee roasters call their coffee roasts “espresso beans” when they are not. The uninformed consumer will purchase this product assuming it is compatible with their espresso machine.
However, when they open the bag they may find coffee beans that are too dark roasted, oily, and will definitely wreak havoc on espresso machines with prolonged use.
There are two main problems with really dark roasts:
- Dark roasts have significant surface oil; and
- Dark roast make your coffee taste burnt, smokey, and bitter.
Understanding the coffee roasting process
All coffee beans start off green. As they roast, their color will change depending on the length of time they roast and the temperature at which they roast. For example, if they roast for a shorter amount of time at a higher temperature, they will be darker in color. As coffee beans roast, they begin to release oils.
The darker the coffee bean is roasted, the more surface oil it will have. Therefore, very dark roasts will be extremely oily. In fact, they will look and feel greasy.
The oil found on the surface of the beans clings to the machine components and causes problems. The oils from the coffee beans will eventually damage the espresso machine.
Very dark roasts will taste burnt and bitter. The oil becoming rancid is due, in part, to a build up of rancid oil.
People who say they don’t like espresso often haven’t had it made with fresh, properly roasted beans, or from a machine that’s well-maintained. Who likes a burnt and bitter aftertaste?
Oily beans formation
In order to understand the benefits or drawbacks of oily beans, we first need to understand the science behind it.
This is a brief overview of what happens to the beans during the roasting process. Coffee magic is created from coffee beans, which are actually seeds.
-When the fresh green beans are first roasted, they go through a process called the Maillard Reaction. The amino acids and sugarsreact to each other when there is heat, and this creates a brownish color.
The “first crack”
The next stage is the important “first crack”, which is when you can hear a cracking sound while roasting the beans. This is an important step!
The reaction is a type of chemical reaction in which energy is absorbed from the surroundings in order to create a new product.
The bean is absorbing energy in the form of heat, which is causing the water molecules to build up pressure. The pent-up energy is released when the bean cracks.
When coffee beans are roasted, the heat causes various chemicals inside the bean to react with each other. This creates new compounds such as aldehydes (which give coffee its characteristic smell), caramelized sugars, acids, and lipids.
I don’t want to overwhelm you with the process.
It’s important to realize that after the “first crack” the coffee bean’s shell is compromised and the compounds inside the bean will start coming out.
The amount of time you cook the beans after this moment will determine the roast. Mild, medium, dark, espresso.
The “second crack”
Once the beans are heated sufficiently, gasses like CO2 begin to accumulate and you’ll hear a crackling noise along with the possible sound of oil frying.
The bean is absorbing more water and the coffee oil is being forced to the surface. The coffee beans are now considered a darker roast.
Oil is found on coffee beans as a result of the roasting process. Your take away from this process? The oil from roasted beans is found in the center of the bean.
If you roast the bean long enough, it will become a dark roast. You will start hearing a “second crack” indicating that the oil will be forced to the surface.
However!
This means that dark roast coffee beans are less likely to be oily. No, roasting the beans for a longer time will not make the coffee oil come out of the beans faster.
Oily beans affect espresso machines
If you roast the beans too much, they will be oily and will leave a greasy residue on all your machine components. ifeel the oil with my fingertips to createa a smooth film I use my hands to smooth out the oil on the surface of the pan. You know how hard it is to clean, right?
The same holds true for espresso machines. If you don’t clean your coffee machine regularly, the oil from the coffee beans will build up and make your machine sticky. The quicker you clean the oils off the surface, the easier it will be.
Here are some issues that will occur if you use over oily coffee beans in your espresso machine. You may notice:
- Sticky bean hoppers which will impede coffee beans from flowing smoothing into the grinder.
- Machine grinders will become gummed up causing coffee grounds to stick together and become solid and clay like.
- Screens on brew units, portafilters, or even mocha pots will become clogged and the machine will struggle to produce a coffee or the coffee will flow out painstakingly slow.
If you use oily coffee beans in your espresso machine, you will have to service your machine sooner than if you had used non-oily coffee beans. If you have been using oily beans, you need to get your machine thoroughly cleaned by an authorized service center and use the right beans moving forward.
Oil on coffee beans affecting the taste
Yes, it does. The amount of oil that can be extracted from an area depends on the location of the oil.
A light roast coffee will have a sweeter, less intense taste because most of the oily goodness is still trapped inside the bean. Some coffee enthusiasts believe that this is the natural “origin” flavor of the bean, which has not been affected by excessive roasting.
A light roast is best if you want to be able to taste the different flavors. A medium-rare or rare steak is more flavorful than a well-done steak because it has more of the steak’s natural flavor.
Yea kind of a weird analogy, I know. But it kind of works, right?
The coffee oil contains many of the same flavors as the coffee. However, when the oil comes to the surface, it reacts with oxygen, which changes the flavor.
It becomes more bitter. The darkness of the roast is what gives the coffee its fuller, more bitter, and bolder taste. A dark roast is not necessarily a bad thing. I personally enjoy a dark roast from time to time, but it is definitely different.
This process of the oil reacting with oxygen is called oxidation.
What to look for in coffee beans for an espresso machine
When choosing beans for your espresso machine or any coffee appliance consider the following:
- The roast: you want medium to medium dark roasts. Don’t assume that beans labelled espresso are necessarily the correct roast.
- The look and feel of the beans: If you can visually see an abundance of oil on the surface of the beans and they feel oily, then they are not ideal for your espresso machine.
- Coffee Blends: each bean varietal responds uniquely to the roasting process. Some varieties will naturally produce more oils. Buying coffee blends helps to balance the amount of oil in the beans. Some oil in coffee beans is important because it adds to the flavor and body of the coffee it will produce. The beautiful crema, a hallmark of a good espresso is also a result of emulsified oils.
Popular coffee bean brands that are generally oily
I have had over 30 years of experience in the sale and service of super automatic espresso machines. There are a few brands that are more likely to cause problems with surface oil and espresso machine function.
Starbucks and Kirkland espresso are two brands you should avoid.
Avoiding oily coffee beans in your espresso machine
In short, oily beans will affect the taste of your espresso and more importantly, oily coffee beans will shorten the lifespan of your machine.
If you keep using oily beans, you’ll have to pay for expensive repairs and your machine will be out of use for a while. The most worrying thing is that you might have to face a morning without your favorite drink.
You shouldn’t drink non-oily light roast coffee immediately after it has been roasted, as it can indicate freshness. You see, there is a degassing period that occurs.
CO2 that is normally released during the second crack of dark roasts will still be released.
Since the bean is no longer exposed to heat in the roaster, this will require time for thebean to cool down. Usually 48-72 hours. Eventually, some oil may rise to the surface, making even light and medium roasts appear shiny.
Dry beans can also be a sign of staleness…. Confusing I know. But it makes sense, and here is why.
The coffee beans will eventually dry out after all the coffee oil seeps out. Now you know your coffee beans are stale. If you are extremely thirsty, you can drink sea water, but it will not be tasty. The flavor is no longer there.
Hey, if that’s all you’ve got, you can’t be picky.
Oily beans can mean the coffee staleness
Many people believe that coffee that is oily is old and not fresh. I can see why that is the case.
It is true that no matter how long you roast beans, oil will eventually appear on the surface.
A ton of oil on the beans would logically mean that they were just sitting out. This can be used as a general guideline for determining staleness.
Instead of throwing away your oily coffee beans, try this. A very dark roast can get super oily due to the long roasting time, but it can still be “fresh.”
I would only drink it if you are willing to take the risk. Honestly, what is the worst that can happen? After tasting the coffee, you express your distaste for it by exclaiming “Curse you Jolly Roast for telling me that oily coffee beans would taste good!” and then open up a new bag of coffee.
Oil coffee beans go stale faster
Generally speaking, yes they do.
The oily appearance of coffee is a result of time, unless you have a dark roast. The more time that passes, the more oily and oxidized the coffee beans will become. The amount of oil in the bean will decrease over time until there is none left.
If you don’t want your coffee to be flavorless, you should avoid letting the beans oxidize.
This is why dark roast coffee goes bad faster than light roast coffee. The dark roast is further along in the oil oxidation process!
Conclusion
Coffee oil is contained within the coffee bean. We release these oils by roasting coffee.
A light roast will keep the coffee oils in the beans’ shell better than a dark roast. A darker roast coffee bean will have more of the cell walls broken down, forcing more of the oils to the surface and making the bean appear more oily.
When coffee beans are roasted, they release oil due to a natural “degassing” process. The more time coffee sits out, the more likely it is to become oily.
The amount of oil in coffee beans decreases over time, and eventually the beans become dry and stale.
Oily beans are a better indication of roast level than freshness.
Coffee beans that are oily are neither bad nor good, they are just a thing. The best way to tell if coffee is stale is not by the amount of oil, but by the lack thereof.