You might have heard that oily beans are better for espresso but also that oily beans are bad for espresso machines and grinders. who’s right? Here’s what you need to know.
While it’s unlikely that the use of oily coffee beans will completely break an espresso machine or grinder, it does raise maintenance requirements considerably, especially for a grinder and espresso machines with built-in grinders. Slightly lighter roasted beans don’t have this problem.
Keep reading below to find out what goes wrong with oily beans exactly and what you can do about it.
Are Oily Beans Bad For An Espresso Machine?
Oily beans are an indication that the beans are very dark (over) roasted. This destroys the cell walls and lets the natural oils of coffee leak out. Oily beans are dark roasted beans and that’s what brews the espresso you know and love. But is that oil going to be a problem for your espresso machine?
Suggested: Are oily beans good for espresso?
Using oily beans in an espresso machine is not going to break it but it does raise the cleaning requirements quite a bit. You’ll have to clean the grinder and all the places the grounds reach more often. Some machines will be much more sensitive than others. This is largely because of the design which you can’t do much about.
Super-automatic espresso makers and grinders are the most sensitive to oily beans. Manual espresso machines are not too bothered by them.
Oily beans (Like the Illy ones on Amazon) are dark roasted beans and that’s what brews the espresso you know and love. But is that oil going to be a problem for your espresso machine?
Oily Beans in Grinders
Those oily beans could produce the taste you’re after. However, oily beans can potentially be a problem with your espresso grinder. The oils on the outside of the beans can combine with the fine coffee grounds you need for espresso and make a kind of sticky, muddy substance. This can clog up the teeth of a grinder and prevent other beans from being ground properly.
The beans can also stick together in some cases which can sometimes lead to the beans not being fed into the grinder properly.
With other brewing methods where you need a coarser grind, this is less of an issue but for espresso, the beans have to be ground fine. The finer you grind the more likely your grinder is to get clogged because it creates that clay-like substance quicker. If you use oily beans, you’ll have to clean your grinder much more often.
Oily Beans in Automatic Espresso Machines
In a super-automatic espresso machine (one that fills the filter basket for you), oily beans can cause problems because the pathways the coffee grounds have to travel through can get sticky and clogged up by the muddy results of the oily beans. That means the filter doesn’t get filled with grounds anymore which means no or very bad coffee for you.
Often on automatic machines the whole unit with all the pathways can be taken out so it’s easy to wash but it’ll have to be done more often than with non-oily beans and can be a pain.
Of course, super-automatic espresso makers also have built-in grinders that can potentially foul as described above.
Manual machines don’t have a problem with oily beans because you have to fill the basket yourself. So while your grinder might have a little trouble, a separate, manual espresso machine will work fine since there are not many places where the grounds touch the machine, just the filter and those are pretty easy to clean.
What Type Of Beans Are Better For Espresso?
So if coffee beans with an oily exterior are better avoided, which type of beans are better for your espresso machine?
As always; it depends. If you like the taste those oily beans create, then go for very dark roasted beans and deal with the results. You can also use slightly lighter roasted beans that are less oily but require much less maintenance.
You should know that there are degrees of oiliness on beans. In general very dark roasted beans are oily but there will still be some oiliness on dark roasted beans. The oilier the beans are, the exponentially worse the problems get. So a light hint of oiliness is usually not a big problem.
Try some beans that are a little lighter (not light). Medium-dark to dark is good for espresso while usually not bean oily. You can’t really extract lightly roasted beans properly while making espresso unless you’ve got some very serious equipment.