About this Video

• Video Title: Gaggia E24 - I was Wrong
• Channel: Espresso Hackers
• Speakers: The speaker's name is not explicitly mentioned in the transcript.
• Duration: 00:04:35

Introduction

This video is a correction and explanation from a previous video about the temperature stability of the Gaggia E24 espresso machine. The speaker initially attributed the machine's improved performance to a new thermostat and brass boiler. This video revises that assessment, explaining the actual reasons behind the improved temperature stability.

Key Takeaways

• The speaker's previous assumption that a new thermostat contributed to the Gaggia E24's improved temperature stability was incorrect. The machine uses the same 107° thermostat as previous models.
• The improved performance is primarily due to the 25% larger brass boiler, which compensates for brass's slower heat transfer compared to aluminum. Calculations show the brass boiler achieves a final temperature 5.7° hotter than an aluminum boiler under similar conditions.
• The discrepancy between the PID-measured temperature (104°) and the thermostat's shutoff temperature (107°) is likely due to the different locations of the thermocouple (PID sensor) and the thermostat within the boiler. The heating element heats the lateral side of the boiler first, leading to a temperature difference between the top (thermocouple) and the side (thermostat).

1. The transcript doesn't detail the specific calculations used to determine the compensation of the brass boiler's larger volume for its lower conductivity. It only mentions simplified calculations assuming 100°C water in both boilers, adding 60ml of 25°C water, and applying 1300W for 15 seconds, with Manus assisting in the computations. The exact formulas and parameters are not provided.

2. The transcript states the thermostat is located "in the lateral of the boiler where the heating element is located," but doesn't give more precise location details.