Oily Coffee Beans: Everything You Need to Know

crazy by Editorial Staff | Posted on June 25th, 2022

You may have asked why some have a shiny appearance while some look dry if you have ever observed oily coffee beans. So, what is the narrative? And is it a characteristic or a flaw?


Why are some coffee beans oily?

Oily coffee beans, in the form of oil, result from lipids rising to the surface inside the bean. This can occur after a long roast or when beans are preserved after roasting more steadily. It doesn’t generally mean that a coat of oil on beans is low quality or too old, but it does recommend a few reasons to explore.

coffee in mug on coffee beans

Are oily coffee beans bad?

Coffee is a drink of nuance, so the reply is somewhat tricky. You may hear contradictory statements regarding “oily beans are old and stale.” and “oily beans are fresh and well roasted.”

You can first consider how well the beans were roasted to decide if the oil is a positive sign or a negative sign. If you notice oil on a light or medium roast, it may have been kept for a long time without an appropriate container. On the other hand, it could be pretty fresh if you see that on a dark roast.

If you own a super-automatic coffee machine, you must watch out for oily beans since these machines are susceptible to clogging and output issues if used with oily coffee beans. More on this later.

However, visible oils on coffee beans don’t necessarily mean stale or lower quality beans. Instead, oils on the beans result from a natural oxidation reaction that occurs in roasted beans and over time.

close-up photography of brown coffee beans

What’s inside the coffee beans

The sensation we get while drinking coffee is triggered by lots of chemicals. Bean is a seed, and its endosperm—the reproductive part—is filled with carbohydrates, water, caffeine, amino acids, and lipids. In addition, each reacts differently to heat during roasting and water during brewing.

For starters, the essential caffeine molecule is water-soluble and extracts easily, but on its own has an awful taste. Rich aromas and flavors are produced by volatile compounds formed by heating sugars and proteins. Organic acids are guilty of most of the sour tastes in coffee.

Lipids from the oils of the coffee bean, whether hidden deep inside or recognizable on the surface. These oils bear most of the flavor compounds and impact the mouthfeel of brewed coffee.

How coffee changes during roasting

coffee beans in grey container

Coffee beans alter drastically during roasting. Water turns to steam, raising the internal pressure, and the beans change color due to a heat-induced reaction between amino acids and sugars called the Maillard reaction. The beans’ cellulose structure finally starts to fall apart due to an audible popping sound dubbed “the first crack.” by roasters.

The sugars caramelize, and the dominant flavors shift from the “origin” characteristics because of the bean’s particular variety and the growth factors to the “roast” characteristics. Depending on the equilibrium they want to accomplish, many specialized roasters pull their beans from the heat around this stage.

Keep roasting, and the deeper layers in the beans break down, contributing to the phenomenon known as the second crack.” Heat exposes the endosperm and renders the outer layer more porous, forcing the coffee’s oils to the surface.

Since coffee oils have flavor, does that imply that oily beans make coffee tastier? Not precisely. The oils originate within the bean. It is where they can stay for a couple of reasons. The oil becomes exposed to oxygen when it is on the ground surface. They lose complexity as they oxidize and take on less pleasant tastes.

How can you tell if a coffee bean is oily?

stack of coffee beans on person's hand

Check if the beans have residue. If you pick up a handful of coffee beans and it leaves a residue on your hands — or if you can see residue inside a bean bag — that means they’re oily and freshly roasted. Lighter roasts aren’t as oily, so don’t expect as much residue as a darker roast.

  • If there is oil on the top of a medium- or light-roasted coffee, it’s usually been there for a long time and can taste dry and old.
  • A dark French or Italian roast, on the other hand, may suddenly look oily. Expect the roast flavors to overwhelm these beans’ flavor profile, including savory flavors of smoke or perhaps even charcoal.

Roast level is a matter of taste, but you’ll still get a great cup when drinking fresh coffee. Next time glossy beans catch your eye, recall that more oil migrates to the surface of the bean during prolonged roasting times and more extended storage periods after roasting.

In fact, the more a coffee bean is processed in any way, the faster the coffee oxidizes and the oilier it becomes.

That’s why decaf coffee also gets oily quickly. Additionally, as coffee sits, oxygen will continue to react with the bean compounds and increase the bean’s appearance outside.

Therefore, oily appearance has become a marker for old or poor quality beans, leading to the misconception that all oily beans are bad.

Conclusion

Let your eyes and your nose drive you. While oily coffee beans’ shiny appearance is not a direct indication of consistency or age, if you choose a lighter roast or if the beans are not quite dark and no roast date is mentioned, it is an attribute to steer clear of.

You have power over your coffee. Most people brew in a grinder with a few scoops of beans, fill the coffee pot with water, and enjoy the coffee they put in the pot that morning, not realizing how it would affect the taste. You’re out on some fun.

You can modulate your coffee’s flavor profile by changing the bean-to-water ratio or grinding. So play with it and make every bean taste how you want it. Change your ratio and grind finer if a bean isn’t bold enough.

Since each person likes different flavors in their cup of coffee each morning, they can brew a cup of coffee as they want. Brewing guidelines still exist, depending on the brewing process, so if you don’t like it, you can adjust how you use the guidelines. This is why we have our site to help! Or you can buy a Keurig and call it a day.

FAQs

My coffee/espresso machine is clogging from all that oil. How do I fix this?

Go fresh, and avoid dark roasts. If you love dark or decaf, buy smaller batches. Use a burr grinder to grind coffee beans that are too oily for automatic coffee machines. Burr grinders are easier to take apart. Also, use light roast beans since they are less oily; they will last longer in your pantry before becoming oily. Artisan roasters have a variety of lighter roasts for your daily espresso or coffee needs.

How do you dispose of coffee oil?

Use a brush, dish soap, and warm water to scrub off oils and coffee stains. Sprinkle baking soda on your brush for persistent coffee residue, then scrub away. Rinse well, so your next cup isn’t like soap—dry, soft cloth.

Can you dry out oily coffee beans?

No, while oilier-roasted coffee beans cannot be dried at home, they can be used differently, like using a French Press when brewing a cup of coffee brew with oilier beans, since they are easier to clean. And don’t be tempted to wash the beans—you’ll end up with a very deceptive, flavorless brew. Using a super-automatic or semi-automatic coffee machine, it’s always best to buy the roast blend, giving you less oil on the coating. To be safe, choose light or medium roast coffee.

How do you keep coffee beans from getting oily?

The best way to avoid oily beans is to buy a light or medium roast coffee. If you notice an oily surface, these beans were left out too long before packaging. You’ll end up with a bland or stale coffee. Beans are fresh and packaged once they’ve been roasted. Once you open the packet and expose the beans to oxygen, a chemical reaction occurs. If you don’t seal your coffee in airtight containers, this chemical process will be hurried. And you’ll get oiler coffee beans sooner than you want!

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Editorial Staff

The editorial staff at Crazy Coffee Crave is a team of coffee enthusiasts & Baristas who enjoy the one thing we all think about as soon as we get up in the morning. Trusted by thousands of readers worldwide.