Good coffee capsule and pod production requires more than just roasting, grinding, and packing coffee into pods and capsules. It also requires an extra step to make sure the density of the ground coffee is optimal for capsule and pod brewing. To understand how density works and its role, we must look at the following:
- The coffee particles’ shapes when they exit the grinder and how to optimize their shapes for greater density
- The use of water pressure in capsule and pod coffee makers and how density is a factor to increase extraction
Coffee’s shape when it leaves the grinder
Coffee particles are not smooth and spherical when they exit the grinder. They are jagged and non-spherical, which means they tend to fill the capsule inefficiently. With less coffee in each capsule, the results are a weak and under-extracted cup of coffee.
Using a process called densification, the coffee particles are literally rounded out, sometimes even having many smaller fines clustering together into larger sized particles. On a microscopic scale this means considerably more total dissolvable solids can fit into the same amount of space.
The role of water pressure, and density as a factor
Densification is not a new concept. Tamping an espresso is basically a form of densification. It not only serves to fit more coffee (and dissolvable solids) into the portafilter, but also provides the resistance needed for the hot water to forcefully extract the crema and volatiles in such a short brew time.
Like espresso machines, capsule and pod coffee makers also use pressure to extract the coffee’s flavor and volatiles. Densified coffee in pods and capsules provides an optimal amount of resistance for the pressurized water to extract the dissolvable solids of the grounds.
The result is the consumer enjoys a better cup of coffee.