We get a lot of questions about shiny beans, and there’s a lot of misinformation out there. Shiny beans aren’t bad! Here’s what’s really happening when your coffee looks shiny or feel oily.
As we know, coffee is a fruit and what we call “beans” are actually the seeds of the coffee cherry. These seeds have naturally occurring oils and when the beans are washed, hulled, dried, and roasted, the oils start to turn from a solid to a liquid.
During roasting, the cell structure of the bean breaks down and becomes more porous, so the oils inside the bean expand, melt, and rise to the surface. It takes a few days after roasting for all the oils to come forward.
So what does the oil tell you about the taste of your coffee? The more shiny and slick your coffee is, the more developed the roast. Basically, the longer a coffee is roasted, the more the oils melt out of it, so the shiniest coffees are usually dark roasts. Darker roast coffees with more developed oils will lean towards the chocolate end of the flavor spectrum, and probably pair great with milk.
It’s important to remember that all coffees have oils, every single one of them. The oils you see on the outside of a dark roast are also present inside a light roast – it’s simply the case that the roast was not developed to a point that the oils inside the bean melted and rose to the surface.
So if you like chocolatey coffees, don’t worry about shiny beans. If, however, you open a bag to find that the oil is no longer slick and smooth, but gummy and sticky, the oil has aged so the coffee was roasted a while ago and might not taste too great.
Shiny beans. Now you know what it means.