I get asked this question a lot! Usually after someone sees the coffee I roasted for them or sees my beans as I prepare some coffee.
The fact is almost all commercially roasted coffee is shiny. The shiny or oily texture of the bean is not a good thing at all. On the contrary, the oil being on the outside of the bean is robbing you of flavor! The reason this continues to happen makes good sense if you are a big coffee producer/roaster. The reason is more roasted coffee in less time means more money for the coffee roaster. I notice this shiny coffee in Starbucks Coffee, Seattle’s Best and even Costco’s in-house roasted beans are shiny. So… even more reasons to roast your own coffee at home.
(Dull Beans-Oils are still locked inside the bean)
Here’s how the coffee beans get shiny…As the green coffee beans roast, the moisture in the beans gets cooked out and the sugars begin to change. The shininess is the coffee’s oils oozing out to the surface of the coffee bean. This occurs when the roast temperature is above 450 degrees Fahrenheit. For big money, roasters time is money! So..in an eight hour day if you can roast a batch of coffee at 600 degrees in 10 minutes plus 10-15 minutes to cool, that would be a lot more batches and profits than roasting at 410 degrees Fahrenheit for 17-18 minutes plus 10-15 minutes for cooling.
Just like any natural product the concentrated, essence is in the oils. So why would you want those shiny, oily beans? You’re losing flavor with the oils left in the bag. Oils left on the sides of your storage canister, oils that stick to your coffee grinder! Those oils belong in your cup! So when it comes to coffee, I would rather have my oils locked inside the bean until I prepare my coffee and extract those amazing complex flavors in my cup!
Let me know if you would like me to address any coffee related topics. I respond to all feedback. Life is way to short to drink bad coffee!