When you’re looking at instant coffee at your local supermarket, chances are you’re looking only at spray dried coffee. It’s, by far, the more common instant coffee creation process.
In this method, coffee beans are brewed and reduced to a thick concentrate. This concentrate is then sprayed as a mist in a chamber filled with swirling hot air (400-500 degrees F). The heat rapidly evaporates the water from the concentrate, causing the coffee to fall to the floor in dry clumps.
This process is pretty fast and can be done using huge machines with high output. When you compare the speed of spray drying to freeze drying, it’s no wonder why giant coffee companies prefer this one.
However, there is a major drawback. Applying that insane heat to the coffee concentrate destroys the flavor. The coffee aromas evaporate and disappear and the chemical structure of the coffee itself is changed, hurting the flavor.
In fact, this process eliminates so much flavor that most companies using this method have to capture the aromas from other pre-ground coffee and insert them into the instant coffee package. The aromas you smell when you open up an instant coffee package aren’t even from that coffee—they were artificially shot into the bag and evaporate away as soon as they’re exposed to oxygen.
The industry standard of spray drying is generally a quality-killing process. When our founders, Kalle and Josh, were getting started, they knew they had to find another way.
The second method for creating instant coffee isn’t one that’s used by many coffee companies in the United States. It’s a little more common in parts of Europe, but by and large, it’s still a fringe process.
This method is more complicated, takes longer, and can’t be done in huge batches like the big coffee giants need. Rather than one step like with the spray drying method, there are three.
- The brewed coffee is frozen at subzero temperatures. Our Head of Coffee, Umeko, brews the freshly roasted coffee using a process specially designed for Sudden. The result is frozen below zero and the freeze-drying machine creates a vacuum to lower the pressure.
- A hint of heat is applied in the ‘primary drying phase’. Never going above zero degrees, a small amount of heat is applied to the frozen coffee in order for the water to sublimate. Essentially, the ice goes directly from a frozen to a gaseous state, skipping the liquid phase entirely and leaving behind mostly dry coffee crystals.
- Slightly more heat is applied. This ‘secondary drying phase’ uses a bit more heat to turn any remaining water molecules into gas. The coffee crystals that are left are now complete dehydrated—and all under zero degrees.
This process creates a higher quality instant coffee for a few reasons.
- The lower temperature preserves aromas. Rather than being evaporated instantly from the crazy hot temperature, the aromatic compounds are allowed to remain inside the coffee crystals (and ready for your enjoyment).
- The lower temperature maintains the chemical composition. Without the presence of heat, the acids are able to remain acids, the sugars are able to remain sugars, and the complexity of a delicious coffee is preserved.