How Keurig's Original Single-Serve Coffee Pod System Works

This 1994 patent describes the original Keurig system for brewing single cups of coffee using a special filter pod that holds coffee grounds and separates them from the brewed liquid.

What it covers

This patent details a system for brewing beverages, specifically coffee, using a special cartridge. The cartridge has a base and a cover, both impermeable and pierceable. Inside, a filter element divides the cartridge into two chambers: one for beverage extract (like coffee grounds) and another for the brewed liquid. When you use the machine, liquid is injected into the first chamber to combine with the extract. The filter then lets the brewed beverage pass into the second chamber, from where it flows out. Claims 1 and 2 describe the core components: a housing with a brewing chamber, a pierceable cartridge inside, and means to inject liquid and collect the beverage. For example, Claim 15 specifies how the liquid inlet might go through one part of the housing and the outlet through another.

What it doesn't cover

• —Beverage cartridges that are not internally divided by a filter element.
• —Systems where the filter element does not create two separate chambers within the cartridge.
• —Cartridges that are not pierceable by inlet and outlet means.
• —Brewing systems that do not use a removable cartridge.
• —Methods of brewing that do not involve combining liquid with a beverage extract stored in a chamber.

The clever bit

The key innovation was creating a self-contained, pierceable cartridge where the filter element itself acts as a divider, precisely separating the grounds from the brewed liquid and ensuring a clean, consistent brew without complex internal machine mechanisms for filtration.

Why it matters

This patent is foundational to the single-serve coffee revolution. It describes the core technology behind the Keurig brewing system, which transformed how people make coffee at home and in offices by offering convenience and variety in a single-cup format.

Real-world examples

• 1.Original Keurig K-Cup brewing machines
• 2.Early Keurig coffee pods