What Are Oily Coffee Beans

Not all coffee beans look the same. While some are dark and dry, others are light and oily. Various factors affect the look of the coffee bean. The age of harvest, the age of roasting, and storing conditions all can affect coffee beans’ look. 

What Are Oily Coffee Beans?

Oily coffee beans are those with an oily coating on the outer surface. The reason for the coffee beans’ oiliness is the lipid coming from the inside to the beans’ surface. If you spot oiliness on the beans, it does not mean that the beans are of poor quality. But there are certain things that need consideration.

Should Coffee Beans be Oily? 

Not all coffee beans are oily, but some are. The reason for the coffee beans’ oiliness is the lipid coming from the inside to the beans’ surface. If you spot oiliness on the beans, it does not mean that the beans are of poor quality. But there are certain things that need consideration. 

How Does Coffee Bean Become Oily? 

A coffee bean contains hundreds of chemicals that are responsible for its unique taste. It contains caffeine, carbohydrates, water, sugar, and lipid. When roasted, each of these elements reacts differently to heat. 

A coffee bean has a naturally occurring oil inside it, which is in solid-state. When you roast a coffee bean, the water inside the bean converts to steam. This increases the pressure inside the bean. The beans gradually turn brown and begin to break. The sugar inside the bean caramelizes, and the beans taste start changing. Most of the roasters pull out the beans around this time. But if you continue roasting, the outer shell of the bean becomes porous. This is when the lipid within the beans come out in the form of oil. Thus, oiliness in the beans is caused as a result of excessive roasting and storage.

All beans, when roasted, give out oil. Whether it is light, medium, or dark roasted, the oil comes out during the roasting process. But since the dark roasted beans are roasted more and for a longer duration, you tend to notice more oil on its surface. 

Does Oily Bean Taste Better? 

The oil that comes out should ideally be inside the bean. But because of excessive roasting, it comes out. Once the oil reaches the surface, it gets mixed with the oxygen in the atmosphere. As a result, it loses complexity and tastes less flavorful. 

If a light or medium roasted bean has oil on the surface, it means that the oil had stayed there for long. This leaves a flat and stale taste. 

But if a dark roasted coffee has oil on the surface, it may not give a stale taste. It is suitable for consumption. But you might notice a smoky or charcoal flavor in addition to an oily look. On the other hand, if you notice a dark roasted dry bean, it means that the bean has gone bad. If you prepare coffee with dark roasted dry beans, then you will get a tasteless and bitter cup of coffee. 

Ideally, you should consume coffee a few days or weeks after roasting. But if this cannot be done, then you should store it in a sealed bag. This prevents the exposure of coffee to the oxygen outside and prevents it from becoming stale. 

What Are the Advantages of Using Oily Coffee Beans? 

When you spot oily coffee beans, you tend to associate it with inferior quality. But this need not be so. There are various advantages of using oily coffee beans. 

• Roasted recently 

The oil on the coffee bean does not last for long. It degrades and decomposes, and eventually, the coffee beans become dry and dull. Once roasted, the coffee will stay fresh for 15-30 days. After that, the oil on the surface gets mixed with oxygen and becomes stale. Thus, if you have dark roasted coffee with oil on the surface, it means that the beans are recently roasted and fresh. 

• Comes from a good roaster

If you have purchased a good quality bean with that shine on the surface, it means that it has come from a good roaster that supplies good quality beans. Otherwise, the beans would have gone stale as a result of the excessive stocking. This is because high-quality roasted coffee has a very short turnaround time. 

How to Tell Whether a Coffee Bean is Oily? 

The first sign of oily bean is by look. An oily coffee bean will have a special sheen than a dry one. Secondly, when you touch the bean, you can feel the oiliness in your hand. Thirdly, if you spot residue on the bag where you store the beans, it is also an indication that the beans are oily. 

What Are the Causes for Oiliness in Coffee Beans? 

There are various causes for oiliness in coffee beans.

• Roasting

Coffee beans become oily because of excess roasting. Thus, if you spot oil on the surface of beans, it indicates that the bean has been roasted for long. This is the same reason why you do not spot oil on lightly roasted beans. Oil usually appears on the beans several days after roasting. 

• Excess processing

Apart from roasting, excess processing of beans in any form can also result in oil production. This is the reason why you will find oil on decaf coffee.

• Improper storage 

Another reason for oiliness in coffee beans is improper storage. You should always keep coffee beans in a cold and dark place. If you keep it in a warm place, the beans become oily. You can store coffee beans in the fridge for some time to prevent it from becoming oily. But keeping it for long is not a good idea as the beans absorb the odor from other strong-smelling food items. 

Thus, it is best to purchase coffee beans in small quantities and use it within a short time. 

If you use hard water for brewing coffee, then the water’s calcium attaches to the fat in the coffee. This results in the coffee looking increasingly oily. So the best water to use for brewing coffee is soft water. 

What Are the Misconceptions Behind Oily Coffee Beans? 

Oily beans are also not free from misconceptions. Here are certain myths surrounding oily coffee beans and the facts behind it. 

• Oily beans are bad

Just because oil appears on the surface of the bean does not mean that the bean is bad. Oil appears on the surface as a result of excess roasting. This is why dark roasted coffee beans tend to be oilier than light and medium roasted beans. 

• Oily beans are required to make a good espresso shot. 

It is believed that oily beans are the secret behind a good shot of espresso. 

The reality is that when the coffee shops first started, the baristas purchased oily beans for preparing espresso. This misconception grew from there. You can prepare a good espresso shot with both oily and non-oily coffee beans. The only requirement is that the bean should be of good quality. 

Can You Use Oily Beans in Espresso Machine?

You should never use oily beans in an espresso machine. This is because oily beans leave a greasy residue and get stuck on to the machine parts. Over time, this oil residue becomes gummy and sticky and becomes very tough to clean. It can even affect the overall performance of the machine. 

If you use oily beans in the espresso machine, you will face the below problems.

• The coffee bean hopper becomes sticky, thus preventing the free flow of coffee into the grinder. 
• The grinder becomes gummed up as a result of which the coffee grinds stick together. It becomes solid and clay-like, and you may not get a perfect brew. 
• The different parts of the machine get clogged, and the machine eventually fails to produce coffee. Even if it makes, the coffee flows out very slow. 

If you happened to use oily coffee beans in the espresso machine, you should vacuum it thoroughly. You should also get it cleaned by a technician before using it again. If any parts are not working, you should change it right away.

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