Yes, oily coffee beans not only affect the drink taste but also affect the grinder's performance.

Knowing that the oily coffee beans may affect the drink taste and machine's performance, you must clarify, 'Why are my coffee beans oily?'. It may be a sign of old or over-roasted beans, but these are not the only reason for it. Keep reading to know all the facts about this query.

Why are My Coffee Beans Oily? - Reasons and Drying Remedies

Oily beans affect the taste of coffee drinks significantly; however, you can dry them to restore their original taste. It is possible only when you know what causes the beans to get oily.

Basically, there are a few reasons that may lead to the oiliness of the beans. But, it is quite easy to prevent this situation when you know 'How to avoid oily coffee beans?'. Keep scrolling; you are on your way to getting the exact answer to your query.

You may also be interested in reading about How Much Caffeine in Vietnamese Coffee?

Oily Coffee Beans - Major Reasons

Oily Coffee Beans

The coffee beans can get oil for several reasons, so you can't claim any single reason behind the coarseness of your beans. The most prominent factors may lead to the odd oily beans.

1- Roasting Time

When cracking the reasons for the oily layer on your coffee beans, have you ever wondered if you have committed any mistake while roasting them? If not, consider this factor and determine whether you have roasted them at the right time.

Honestly, the oil on the beans' surface results from the chemical reaction between the beans' constituents and the external oxygen. When you roast them for an extended time, CO2 comes out of the beans and reacts with the oxygen. This oxidation results in an oily layer.

2- Roasting Temperature:

Besides the roasting time, the temperature also affects the texture of your coffee beans. Being an amateur coffee consumer, you may know that the final coffee product is a mixture of your art, the ingredients' chemistry, and the food science.

If you are the master of this art, you may know the ideal temperature for a perfect roast is between 350F-490F. When you disturb the rost temperature or time, the coffee beans will have an oily layer.

3- Dark Roasted Beans:

Those who love bitter drinks will know that dark-roasted coffee beans have an oily surface. If you notice the oil on your coffee beans, these are dark roasted.

4- Old Coffee Beans:

Though not always right to say, the older coffee beans also become oily. So, if you are on the market for beans and find them oily, leave them as these are older. Such beans will not deliver the expected taste.

How to Avoid the Oily Coffee Beans?

How to Avoid the Oily Coffee Beans

When you know what can cause oily coffee beans, you can avoid the possible mistakes to keep them fresh and tasteful. Based on the above-discussed reasons, we can formulate the following preventive measures to prevent the oily layer on the beans.

Right Roast Time: Roasting time is one of the major contributing factors that contribute a lot to making your beans oily. Depending on the temperature, 13-25 minutes is enough for the perfect roast. So, never roast your beans more than this time for a perfect taste.

Moderate Roasting Temperature: Temperature is another major factor that can leave the beans oily and with a bad taste. As 350F-490F is the ideal roasting temperature, ensure the roaster is not heated more than this temperature.

Are Oily Coffee Beans Bad?

The oily coffee beans are not bad for you when you love bitter-tasting coffee. However, it can be a problem for you if you love smoother drinks. No matter the type of coffee user you are, you should know what is wrong with these oily beans.

Clogged Grinder: Your grinding machine repeatedly clogs when you start grinding the oily coffee beans. It is due to the beans you are grinding in it. It is one of the major effects of the dark-roasted and oily beans of coffee.

When you use a Burr grinder or a brewer with an in-built grinder, you'll face this clogging issue more repeatedly than any other machine. So, avoid purchasing such beans as the oily beans will clog the grinder.  

Bitter Taste: If you are a dark-roasted coffee lover, the oily beans will not be a problem for you. But if you love a smooth taste, such beans will be a hard pill to swallow. It is another odd thing about the oily coffee beans.

How to Dry Oily Coffee Beans?

How to Dry Oily Coffee Beans

You purchased the coffee beans and suddenly revealed that these are oily. The next question you'll ask yourself is, 'how to get rid of this oil?'. Hold down; there are still chances to dry your coffee beans without compromising taste. Here are the two possible methods; choose any of them that suits you the best.

1- Mix The Oily Beans With Lighter Roasts

Mixing dark roasted or oily beans with light roasts can help you make your coffee taste better. Follow these steps.

  • Mix both bean types of beans in an airtight container.
  • Shake them well so that they get mixed thoroughly.
  • The light roasts will digest some oil from the dark roasted beans.
  • Ensure you have stored the container in a dry and dry place.
  • Over time, the oiliness level will become even, and the beans will now taste better.

2- Paper Towel Method

Though it is the least practical method to remove the oil from your coffee beans, you can still try this one if you like it. Pat the beans with a clean and dry paper towel; it will gradually remove the oil. However, the paper may leave some aroma in the beans that may affect their original taste.


Oily coffee beans may be the worst experience; however, you can avoid such a situation when you understand the oily coffee beans vs. dry. So, it is good to learn 'Why are my coffee beans oily?' before heading to the beans market.

We have discussed the most obvious reasons for oily coffee beans, accompanied by preventive tips. Hopefully, these instructions will help you make the drink experience better.

Then what are you waiting for? Go and enjoy your favorite drink without any compromise on the taste. We have the latest updates on coffee pods, brewers, and beans for passionate coffee lovers. So, keep in touch with us for more episodes!

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