What Happens to Coffee During the Roasting Process

Real coffee beans look dramatically different than what you are probably used to seeing. 

They start out green before being roasted. 

Here is a look at what happens to coffee during the roasting process.

First of all, the highest quality beans will need to be used.  The type of beans will help determine what level of roasting should be aimed for.  During the process, the beans will gradually change colours, getting darker along the way.


Roast levels range from light to very dark with three main categories including light, medium, and dark. 
Roasting the beans until they are quite dark will help bring out all of the flavours of them and produce a heavier body.  If you use lighter roast, then the resulting coffee will have a lighter taste.

When coffee beans are being roasted, they will undergo many different chemical reactions.  These chemical reactions help transform the beans into a product you will actually want to consume.  One of the main things that will happen to the beans during the roasting process is caramelizing of the sugars.

The beans will also be full of moisture which will be drawn out as they are exposed to the elevated temperatures.  Both of these things will also cause the beans to pop as they near completion.  The first pop you hear while roasting beans will signal they are done at a light roast.  If you leave them in for a little while longer, they will pop again when at the dark roasting level.

Many people are not aware coffee beans start producing carbon dioxide right after they have finished the roasting process.  This CO2 production keeps going between 12 hours and 3 days.  This is the main reason your coffee will not taste as good as it could if you grind it up and drink it immediately after the beans have finished roasting.

After the beans have finished degassing is the best time to use them.  Beans will not stay fresh indefinitely after they have roasted either.  It is best for you to use them within a few weeks after doing so. 
After that, your coffee will have a stale taste.

This is why you should always find out when the beans were roasted whenever you buy them from a store or coffee shop.  The timing will affect the taste greatly. 

Remember you can always invest in a coffee bean roaster and roast your own beans from the comfort of your own home, roasting to the exact roast you want from very light blonde to dark and intense.

Why not browse our range of Coffee Bean Roasters

Coffee bean Roasters

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