Unheated brewing unit for espresso coffee machines with E61 brewing units
The E61 brew group with low thermal conductivity and a water mixing system addresses inefficiencies in thermosiphon-dependent espresso machines by eliminating the heated base and providing flexible temperature control for improved coffee quality.
Patent Information
- Application Number
- DE202025002426
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2025-08-21
- Publication Date
- 2025-12-11
- Estimated Expiration
- 2035-08-31
AI Technical Summary
Existing E61 brew groups in espresso machines rely on a thermosiphon system for temperature stability, which can lead to inefficiencies and require a heated base, limiting flexibility and energy consumption.
A brew group with a low thermal conductivity and low heat capacity material is used, eliminating the need for a thermosiphon system, and incorporates a water mixing system with separate paths for heated and unheated water, controlled by a central unit to set brewing water temperature, and adjusts pre-infusion via pump output.
This design maintains temperature stability without a heated base, reduces energy consumption, and provides flexible temperature control, enhancing coffee quality by optimizing brewing parameters.
Abstract
Description
[0001] The present invention relates to an E61 brewing unit.
[0002] In this invention, an espresso coffee machine is understood to be a coffee machine that brews a coffee specialty using espresso powder with a defined grind. This is usually espresso, but also coffee, caffè crema, and, by adding milk foam, cappuccino or latte macchiato.
[0003] In an espresso coffee machine, the espresso powder (ground coffee, coffee flour) is pressed into a portafilter using a plunger called a tamper, which is a portable vessel for holding the ground coffee, with a filter in its bottom.
[0004] In this invention, the term "brew group" refers to the machine connection that holds the portafilter. Brewing water is supplied to the brew group. The coffee specialty is produced by the passage of the brewing water through the brew group and the ground coffee in the portafilter. Due to the compacted coffee grounds, the brewing water is pressurized during this passage.
[0005] The E61 brew group refers to the brew group introduced by Faema in 1961, which has since become a standard in espresso machine design. It is a heavy brass construction, which retains heat and ensures temperature stability. A thermosiphon system maintains the brew group at a constant temperature. A characteristic feature of E61 brew groups is that the coffee grounds are moistened with water before full pump pressure is applied. This is achieved by releasing an additional volume (pre-infusion chamber) via the brewing lever. This process improves extraction and is known as pre-infusion. The size of this additional volume determines the duration of the pre-infusion. The brewing process is started and stopped using a distinctive lever.
[0006] Brewing water temperature refers to the temperature of the brewing water that is supplied to the coffee grounds in the portafilter.
[0007] Brewing water refers to water that has not yet come into contact with the coffee grounds.
[0008] The quality (variety, growing region, processing method, blend) of the coffee, the amount of coffee grounds used, the fineness of the grind, the pressure with which the grounds are compacted, the dynamic course of the water pressure in the machine, the dynamic course of the brewing water temperature and the duration of the coffee preparation influence the final quality of the coffee. Invention
[0009] This invention comprises an E61 brew group which does not affect the brewing water temperature. The brew group features a brewing water channel made of a material with very low thermal conductivity and low heat capacity. This eliminates the need for a thermosiphon system, and the base of the E61 brew group does not heat up.
[0010] Furthermore, this invention comprises a water mixing system integrated into or upstream of the brewing unit. In this system, the brewing water is drawn from the water source (tank or mains water connection) via two different paths and mixed within the water mixing system.
[0011] One path is equipped with a fixed throttle and is routed through a water boiler heated to at least 105 °C to the water mixing system.
[0012] The second path directs unheated water to the water mixing system via a variable throttle connected to a central control unit.
[0013] The brewing water temperature is determined by the flow rates of the hot and cold water. A temperature sensor located near a central control unit is part of the mixing system to monitor the brewing water temperature.
[0014] Brewing water that has not yet reached the desired brewing water temperature is directed into the dirty water of the espresso machine via a switchable drain connected to a central control unit.
[0015] The pre-infusion characteristic of the E61 brew group is produced by varying the pump output of the water pump instead of using a pre-infusion chamber.
Claims
[1] This invention comprises an E61 brew group which does not affect the temperature of the brewing water. The brew group has an insert, which carries the brewing water, made of a material with very low thermal conductivity and low heat capacity. This eliminates the thermosiphon system and the base of the E61 brew group is not heated. [2] This invention further comprises a water mixing system integrated into or upstream of the brewing unit. In this system, the brewing water is supplied from the water source (tank or mains water connection) via two different paths and mixed in the water mixing system. One path is equipped with a fixed throttle and is routed through a water boiler heated to at least 105 °C to the water mixing system. The second path directs unheated water to the water mixing system via a variable throttle connected to a central control unit. The brewing water temperature is determined by the flow rates of the hot and cold water. A temperature sensor located near a central control unit is part of the mixing system to monitor the brewing water temperature. Brewing water that has not yet reached the desired brewing water temperature is directed into the dirty water of the espresso machine via a switchable drain connected to a central control unit. [3] The pre-infusion characteristic of the E61 brew group is achieved by varying the pump output of the water pump instead of using a pre-infusion chamber. For this purpose, a pressure sensor is integrated close to the E61 brew group and is connected to a central control unit.