The difference comes down to where the temperature is measured. Traditional machines measure the temperature directly inside the boiler. Because the water loses heat as it travels from the boiler through the machine's metal components to the group head, it can cool down by 6 to 8°C (around 11 to 14°F) by the time it touches the coffee. In contrast, the Decent machine measures the temperature just two millimeters above the coffee puck, capturing the actual extraction temperature of the coffee slurry.

E61 group heads rely on a large, uninsulated hunk of metal designed to radiate heat into the room. They achieve stable temperatures in busy Italian bars where shots are pulled back-to-back, keeping the metal thoroughly heated. However, at home, if the machine has idled for an hour and you pull just one shot, the metal hasn't been actively heated by running water. This can cause your shot to be under-extracted and up to 15°C below your target temperature.

An electrically heated group head, like the one used on the Decent, actively controls the temperature of the group head itself rather than relying passively on heat from the boiler. This design ensures that the metal components are always at the proper temperature before brewing starts, making home brewing drastically more consistent and precise.

When you set a target temperature (e.g., 92°C), the machine targets that temperature at the slurry level. Because it initially encounters room-temperature coffee grounds, the machine will automatically pump in hotter water (e.g., 94°C) to combat the cold grounds. As the puck absorbs heat and warms up, the machine dynamically cools down the incoming water. It checks and corrects the water temperature multiple times per second to hit and hold your target extraction temperature as fast as possible.

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