Stages of Roasting Coffee - How Coffee is Made
Are there many stages of roasting coffee? I always thought coffee roasting was like making popcorn. You just put the raw beans in the hopper, press the coffee button and sit back while the coffee starts to pop -- I mean roast!
Well, that’s not the case. Coffee roasting actually happens in many stages, each with its own unique chemical process. Every coffee roaster will give you a different number, but the end product is the same. At Black Ink Coffee Company, we break our roasting process into five unique stages; Drying or Yellowing Stage, Maillard Reaction, First Crack, Second Crack, beyond second crack (French Roast).
Drying - Yellowing Phase
In this stage of coffee roasting, the raw coffee beans are added to the already pre-heated roaster. Even though all coffee is dried before shipping, the insides of the beans are still dense with water. This is because the beans are submerged in fermentation tanks during their early lives after being picked.
For top quality specialty coffee beans, they will typically come in grain-pro bags, with a moisture level of roughly 12%. You may be wondering to yourself if this matters, well yes actually, it does. Coffee beans need moisture in order to achieve certain chemical reactions.
The drying stage, often referred to as the yellowing phase, is when the coffee beans turn from a grassy pigment into a bright yellow color. During this stage, you'll notice that the raw green coffee beans initially give off a grassy odor, but then transform into a hay or wheat odor by the end of the stage.
This stage can be completed quicker (4-5 minutes) with more energy (heat), but it is important that you are able to control and slow down the roast during the other stages which is why I like to take the drying phase a bit slower (5-6 minutes). This will also prevent scorching and tipping which are considered roasting defects because the coffee beans are starting to burn.
Yellow to Brown - Maillard Reaction Stage
Once the coffee is dried, the real magic begins... it is called the Maillard Reaction. This reaction is well known and studied within the coffee roasting business. It is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Some may also refer to this stage as Caramelization and Acid Development.
At this point, the heat from the roaster begins to enhance the coffee’s natural sugars, mmmm sugar. Between the amino acids within the bean and the reduction of sugars, a chemical reaction begins to take place. This reaction is the single most important reaction in the roast for dictating the overall taste of the coffee.
By this time, the water that saturated the beans has now turned into gas. In this second stage, the beans turn from yellow to brown. The wheat smell starts to fade into a distinct coffee smell. As the internal gas starts to expand the walls of the coffee bean, it naturally begins to grow in size. Just like popcorn!
First Crack - Development Stage
This is the most exciting stage so please excuse my excitement. Remember the gas that has been building up inside of the bean? Well, it can’t just stay there forever. Once the bean has too much pressure, it explodes! Kind of like… coffee beans. I bet you thought I was going to say popcorn.
This stage is called “First Crack”, or the Development Stage, and if you were in earshot, you could actually hear it. The sound of these beans cracking in unison is one of the most calming noises in my opinion. Despite the fact that there are mini bombs going off inside of the roaster, these cracks are an extremely peaceful song to witness on a quiet morning.
After the First Crack, the beans natural acids and sugars form a unique and precise bond. A good coffee roaster will know how to get the perfect balance between the two. This may take many hours of charting and cupping, but a determined coffee roaster will figure out how to bring the best out from within a coffee bean.
Each coffee bean behaves differently, so it is important for the coffee roaster to know everything about the bean and his/her roaster. When you throw popcorn into the microwave, do you adjust the time based on where the kernels came from, how they were prepared and the altitude at which they were grown at? I certainly don't, but you need to if you want to roast quality coffee!
Second Crack - How to Roast Dark Roasts
The Fourth Stage is called Second Crack and it is an optional one depending on the type of coffee you are roasting. Most single origins, like the ones often seen in our Instagram, stop just before this Second Crack. However, we do offer a few blends that we like to take into the second crack, like our popular Inkwell Blend, Breakfast Blend and Espresso Blend.
This stage is when darker roasts end, like a Vienna Roast. During this stage, the coffee turns from a light brown to a dark brown and oils can be seen covering the exterior of the coffee bean depending on how long you let this stage take. It is recommended to avoid going past 15-30 seconds into the second crack or else the coffee will begin to taste roasty, baked and possibly burnt.
French Roast - Extremely Dark Coffee Roasting Stage
Roasting beyond second crack ensures that you are achieving the darkest roast. Coffee beans turn from a dark brown to a harsh oily black. An example of this is a French Roast which is like playing with fire, especially if you do not have adequate cooling equipment. Anything beyond this point will run the risk of burning the bean past the point of no return. Or worse, a fire will burst from within the roaster.
Honestly, unless you are roasting this dark for espresso shots or maybe a cold brew, roasting coffee this dark is a bad idea since you are removing all of the flavor nuances and desired chemical reactions away from the end product.
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