Green beans

Coffee beans start off in various shades of green and sometimes yellowish green. They are pits/seeds of fruit.

Beans from various regions around the world are different sizes, density, different moisture content, some beans are washed, some are natural process, some are honey process, and tons of other things that happen before they're bagged in grain pro bags or burlap bags to be sent to roasters around the world.

When it comes to storing the beans, in my experience, I prefer to store them in grain pro bags that sit inside the food safe BRUTE bins.

Grain pro bags are big green bags that help prevent further drying from sunlight and to help keep moisture in the bean and prevents unwanted odors from getting into the coffee beans.

The reason I prefer coffee in grain pro bags is because by keeping moisture in it allows me to dial in a roast once and keep the same roast variables each time I drop a batch of beans into the roaster. It also keeps flavors consistent roast to roast, this is key in keeping each blend or single origin coffee tasting the best it can. I also store it in the BRUTE bins so sunlight doesn’t slowly dehydrate the beans and further keeps unwanted odors from getting into the beans.

How moisture affects the flavor and roast is this. For sake of example. Lets say an Ethiopian coffee bean is around 20% moisture upon a roaster receiving and roasting the first few batches. It isn’t stored in a grain pro bag, but a burlap bag that is just left on the pallet. Over several months the moisture content will be less and less. This does a few things. It will make the first crack very hard to hear and recognize. This is bad because Ethiopians produce a lot of great flavor around this point in the roast. You can either make it a delicious coffee to drink or a bitter and bland coffee.

It will also decrease the roast time because of the smaller moisture content. If a roaster is following their data from roasts they did when they first got the beans it can actually make the coffee bean a darker roast than desired. Which greatly changes the flavors.

Not only that, but, if a roaster is aware of this they will constantly do quality control roasts to ensure the ever changing moisture content stays consistent to their flavor profile.

Now, if you add moisture to the beans, say soaking them in bourbon or aging them in a bourbon barrel. The beans, because they’re so porous will absorb any moisture that is near them. This creates a bit of challenge roasting beans that have been aged in a bourbon barrel or soaked in bourbon.

First, they double in size and weight. This can make getting the beans into the roaster a bit tricky and changes roasting variables for the beans.

Because they double in weight, you will have to use less beans than normal. For example. If your roaster is a 5 kilo roaster, meaning you can roast a max 11 pounds at a time. If you always roast 10 pounds at a time with a regular coffee, for one that’s been aged in a barrel or soaked in bourbon or whiskey, you’ll have to use less, perhaps 6 or 7 pounds at a time to achieve a good roast because it will take longer to draw out the added moisture in the bean to achieve first crack.

Aside from the variables of green coffee beans and how to roast them. Roasters also have to take into consideration the room temperature also. This can speed up or slow down the roasting process especially if a room isn’t temperature controlled.

For me, I notice my roasts slow down by a 1 or 2 minutes in the winter and speed up by 2 or 3 minutes in the summer. This has to do with the roaster taking longer to fully heat up and the air being pulled into the roaster from the air in the room either being cooler or warmer.

Airflow going out of or into the roaster can also change the time it takes for a bean to reach the desired time a roaster wishes to bring it into first crack, how slowly or quickly it develops through first crack, and reaching its desired end state.

These are some of the things I’ve come to learn and notice throughout developing my hand at coffee roasting. These factors can make or break a good coffee and turn a quality coffee bean into a premium roasted coffee bean.