Coffee making

Why Does My Coffee Look Oily – And Is It Bad?

Nothing like a freshly brewed cup of coffee on a rather cold and slow morning to get you up and running, ready for what the day brings. But have you ever brewed a cup of coffee only to find oil residue floating on your coffee? 

If you have been quite observant, the shimmery glares from oil traces on your coffee must have raised some level of curiosity. While many are too absorbed in the refreshing feeling each gulp brings, others can’t help but toss their coffee away. Only to pour another cup to end up in the same predicament.

Are these grounds enough to buy a new coffee maker machine? Where does all the oil come from? Is oily coffee safe for consumption? Read on for answers and more insight surrounding oil in coffee.

Where Does the Oil Really Come From?

Nope, your coffee machine isn’t dirty and you don’t need to throw it away. But no one wants to drink oily coffee. Want to know where the oil comes from?

Coffee beans possess natural oils as part of their composition. 71 percent of these oils are fatty acids. The same as what you find in margarine, some types of meat, and other legumes. If you grind and brew your own coffee, you may notice a slight difference in your coffee beans. Some coffee beans appear dry while other coffee beans appear oily/shiny on the surface. 

Light or medium roast coffee beans tend to have less oil on the surface. Dark roasted coffee beans, on the other hand, have a significant amount of oil on the surface. 

Is Oil in Coffee a Good or Bad Thing?

Contrary to what numerous coffee drinkers and enthusiasts assume, oil in coffee doesn’t necessarily mean that your coffee has gone bad. Finding oil residue on the surface of your coffee cup or in your coffee beans also doesn’t mean that the coffee beans used in brewing are of substandard quality. 

So, no, oil in coffee isn’t a bad thing. If anything, most coffee makers and producers can tell you that oily coffee or coffee beans are the freshest. However, a few majority never miss a chance to rubbish these claims. They are quick to mention that oily coffee is, indeed, of questionable quality. 

According to research, claims from both opposing sides hold some level of truth. See, oil in coffee can be good or bad. To decide whether the oil you see on your coffee is good or bad, you must focus on several factors. 

Whenever you see oil residue in the coffee you made from light or medium roast coffee beans, then that’s a bad sign. In this case, it means that your coffee beans have expired or have been stored incorrectly for a long period.  Perhaps, you used the wrong container, water spilled on your coffee beans, or the conditions/temperatures weren’t favorable to maintain freshness.

Alternatively, oil present in dark roasted beans is a viable indicator that your coffee is super fresh and healthy to drink. 

Besides the pointers above, other additional factors can influence whether or not your coffee comes out oily. They include,

  • Type of Water

There are generally two types of water. There’s soft water and hard water. If you come from an area where hard water runs from your taps or is even sold as packaged water, you are likely to see oil in your coffee. This assuming that you use tap water to brew your coffee. 

Hard water contains an increased level of calcium. Calcium easily bonds with fatty acids in your ground coffee making it more visible. Soft water has reduced calcium content hence no bonding of fatty acids and ultimately no oily residue.

  • Coffee Bean Grade

Coffee beans come in varying grades depending on the coffee bean variety, freshness, and production process.  High-grade coffee not only tastes smooth and crisp but it is also far less acidic. This makes it less likely to produce oily coffee owing to the intricate yet mild production process they’ve been through.

Lower-grade coffee beans are more acidic and can have a significant difference in taste. This type of coffee will certainly have a higher amount of oil residue because it is more acidic and has been through a rigorous production process.

  • Water Filters

If you don’t want to see oil in your coffee, water filters are an excellent way to help get rid of it, albeit, not all of it. Most water filters are designed with an activated carbon coating that can absorb organic residue during the filtration process. Attach your filter to your tap to collect water that has the least amount of impurities. 

Coffee made with carbon water filters is significantly less oily. However, if you add water softener, you can bid good riddance, once and for all, to oily coffee. This is because soft water has a lower chance of reacting with the compounds present in coffee beans. Be sure to change the water filters every six months to continue yielding effective results.

Using water filters is one way to avoid oily coffee. But what about the filters you use on your coffee maker machine? A trick that most people use to effectively filter oil from their coffee is to use two filters instead of the usual single filter when brewing their coffee. While a tiny bit of oil may still seep through, it will be far less obvious on your coffee/coffee cup.

  • Method of Roasting

You probably only know about the dark roast, medium roast, or light roast. But what do you know of the process that gets the coffee bean from its raw form to whichever roast type? The method used to roast coffee beans has a direct effect on there being oil or not in your coffee. 

Flame roasted coffee beans produce a lot of fatty acids and have a burnt/bitter taste owing to the rigorous burning process. Slow roasted coffee has a smoother taste, it’s not bitter, and has a significantly lower amount of oil residue. 

Side note; if you still want to enjoy your coffee but want to evade the sudden rush to your nervous system, slow-roasted coffee is your best bet. Its processing method brings out stable caffeine molecules that aren’t too harsh on your nervous system.

Debunking Common Myths around Oily Coffee/Coffee Beans

If you own an automatic coffee machine, oily in coffee isn’t such a foreign sight. The notion that oily coffee is bad is misconstrued. There is a near endless list of ideas that people have come up with to explain why your coffee or your coffee beans appear oily. But how many of these ideas are true and how many are not? So to separate the wheat from the chaff, below, we debunk common myths around oily coffee.

  • Only Cheap Beans are Oily

Price and the quality of coffee beans have nothing to do with each other, whatsoever. Lower priced coffee from less known brands are thought out to be old and of a lower grade. This is far from the truth. Even the priciest, world-renowned coffee brands can make oily coffee if, for example, the coffee beans used have been stored under unfavorable conditions or if the beans went through rigorous roasting processes.

  • If your Coffee is Oily, You are Making It Wrong

Truth be told, coffee making is an art. But when you’ve made coffee for so long and have developed a level of curiosity about how you can get the best taste, you also realize that coffee-making is a science. To get it out of the way, even the best barristers can make you a cup of coffee that turns out oily. 

Again, it’s not so much about how you make the coffee as it is about whether you are using medium, light, or dark roast beans to brew your coffee. 

  • To Make a Good Espresso Shot, It Must Be Super Oily

Dark roast coffee beans are said to produce the purest, best-tasting espresso owing to its rich flavor and stinging taste. But who is to say that you cannot get good quality espresso from light or medium roast coffee beans? Most coffee drinkers claim that oily espresso is the best but this is only because it is most likely made from dark roast coffee which is the oiliest of the three coffee roast varieties.

Why You Should Avoid Oily Coffee If you Brew Your Own Drink

Do you own a coffee maker machine? You are probably one of those guys who raise a storm and can’t stand oily coffee. Probably because you are worried it will make you fat or that it is unhealthy, right? Well, now that we have established that oil in coffee isn’t as bad as it seems to your health, turns out the story changes drastically when your coffee maker machine is the point of focus. 

Your coffee maker machine bears the heaviest burden of using oily beans to brew your coffee. Most people go for days without needing to clean their machines right after use. The only problem with this is that accumulated oil from brewing too many batches of dark roasted coffee beans can clog up your automatic or semi-automatic coffee maker machine. 

Other issues that crop up from using oily beans include;

Clogged screen. Most coffee making machines have a clear, see-through screen which lets you monitor the brewing process. By using oily beans, you risk clogging the screen which, if left unchecked, ultimately leads to your machine breaking down.

A sticky, malfunctioning bean hopper. A poorly functioning bean hopper means that the coffee beans will not flow appropriately into the grinder. Owing to the sticky oils on the surface, some of the coffee beans will stick on the walls of the bean hopper making the process even harder for your machine.

Faulty grinder. For a coffee grinder to work effectively, it needs to receive dry coffee beans. If you prefer using dark roast beans your grinder is likely to have sticky oil coating its surface. The result is beans sticking together in chunks making it difficult for the grinder to effectively break down the beans into smaller bits. Essentially, you will hear the beans spinning but notice that little to no product coming out of the grinder entering the brew unit.

How can you avoid clogging up your beloved coffee maker machine?

There are two solutions. 

  • Use Fresh Beans

If you prefer light or medium roast beans, only buy your supply in smaller batches so that you only use a fresh pack every time you need to make coffee. Remember poor storage can lead to faster oxidization which can cause your coffee beans to grow oily.

  • Avoid Dark Roast

Medium and lightly roasted beans are naturally less oily and will therefore produce less oily coffee. Dark roasted beans on the other hand are super oily and are likely to produce oily coffee. If you must use dark roasted coffee beans, it’s advisable to use multiple filters when brewing and to thoroughly clean your coffee maker machine often.


The convenience of owning a coffee grinder and brewer machine is one many wouldn’t trade for anything in the world. But most have found themselves choosing to head to their favorite coffee shop to get their daily dose of coffee. Now that it’s clear where the oil in your coffee comes from, turns out you don’t have to be too wound up about it. 

If anything, most avid coffee drinkers will tell you that oily coffee is the most flavorful. If you still can’t stand the sight of the shiny residue at the bottom of your cup, how about get some new filters and opt for medium roasted beans instead of the dark roast beans? 

Want to be let in on a secret? You have likely made up your mind about not wanting to take oily coffee. But you don’t want to trade that for the coffee flavor you crave every morning, do you?. What most people do is go for the medium roast coffee beans. 

Medium roast not only preserves the natural flavors of the coffee beans but also yields a balanced well rounded hot coffee drink that only has traces of oil which is barely noticeable. There, problem solved!

And with that cheers to more coffee!