What is the E61 Group Head?
The E61 Group Head
The E61 group head was originally designed for the Faema E61 model in 1961 by Ernesto Valente. Since its invention, the E61 group head is one of the most used group head styles in espresso machines today. Specializing in passive pre-infusion and providing consistent temperature stability by using a thermosiphon heating circuit, the E61 hit the ground running! With simple parts and operations, the E61 group head has been a faithful component to the rising quality of coffee within the home and cafe. Exemplified by coffee geeks & manufacturers all around the globe still using it 60 years since its invention for instance!
(fun fact: the ‘E’ in E61 stands for Eclipse because of the solar eclipse that happened in 1961!).
- How does it work?
- How can I use it to get the best out of my coffee?
- Our products that use an E61 group
1. How does it Work?
Thermal inertia – thermosiphon – pre-infusion
Firstly, let’s discuss how the E61 Group works! Do not let these scary words push you away, they help make you an awesome cup of coffee! The E61 group head consists of these three key features.
The E61 uses thermal inertia with its chrome plated brass design. By using brass as a material component, it allows the machine to conduct and store heat at a consistent, stable temperature without using an electrical source to keep heated. Regulating a consistent brew temperature helps with the extraction of the oils from coffee to optimize body and flavour.
Thermosiphon heating circuit:
Importantly, E61 groups are designed using a thermosiphon heating circuit. This function operates by drawing water from the boiler into the top of the group chamber. It then sits at a correct temperature ready for espresso extraction. As the water in the chamber cools while the pump is not running, water is cycled from the group chamber back into the boiler ready to be reheated while its refilled with freshly heated water! This ensures that the group head remains at the same temperature with consistency. As all coffee geeks know, consistency is the key to any great coffee experience!
Pre-infusion allows for a better extraction of espresso. The E61 group head lightly saturates the puck of coffee grounds with low pressure so that it is evenly distributed in your shot. This gives the coffee grinds the opportunity to bloom! Pre-infusion allows the coffee grounds to stabilize before receiving the full pressure of the pump for your shot extraction. The E61’s group head contains a small jet with a diameter smaller than 1mm which is used to restrict the water flow that meets the coffee puck. As pressure rises in the cavity the spring-loaded valves inside of the pre-infusion chamber open and as water flow increases. When the pre-infusion chamber is full of water, the brew pressure will enable you to pour an even, consistent coffee.
The E61 group is a semi-automatic machine that has passive pre-infusion. This means you can control how long you would like your shot to be in its pre-infusion stage before its extraction stage where it reaches its pressure limit for your shot!
2. How can I use it to get the Best out of my Coffee?
Secondly, let’s discuss how an E61 can help you get the best coffee possible! The E61 design has a manual lever which leaves the group head in 3 stages.
- Static: off/no water access to coffee.
- Pre-infusion: water can reach the coffee basket without mains pressure.
- Brew: pump is activated with 9-12 bar pressure for coffee extraction.
Gone are the days of leaving the house for a quality cup so put that tin of instant away and never look at it again! For a quality coffee when you can’t leave the house, you can’t go wrong with a coffee machine with an E61 group head! Importantly, our team of qualified technicians are here to service and repair everything that we sell, to give you peace of mind!
3. Our Products that use an E61 Group
Lastly, let’s take a look at the range of machines that provide the E61 goodness!
Check out our manual coffee machines HERE!
Author: Frank Tomaiuolo