Gaggia Classic with PID - Thermofilter testing

Summary

In this video, the creator demonstrates their espresso-making process using a modified Godric Classic machine. They highlight the use of a PID controller and a Taylor thermometer for precise temperature monitoring. The creator explains how the thermometer helps track the boiler's heat, ensuring optimal espresso extraction. They prefer concentrated ristrettos and emphasize the importance of temperature control, aiming for around 198°F for ideal shots. With a thermal filter and simulated coffee puck, they showcase the process, including adjusting the group head temperature and pulling a shot to demonstrate their technique and preferences.

Takeaways

• 😀 The speaker is using a modified Godric Classic espresso machine with a PID controller to manage heat.
• 😀 A Taylor thermometer is used as a secondary indicator to track the temperature of the group head.
• 😀 The PID sensor is located near the heating elements in the boiler, while the Taylor thermometer is near the group head.
• 😀 The Taylor thermometer helps the speaker determine when the boiler has reached the correct temperature, especially since it isn't near the heating elements.
• 😀 The speaker prefers concentrated espressos (ristrettos) and typically fills the shot glass about three-quarters full.
• 😀 The shot temperature tends to drop quickly after pulling a shot, with the speaker noting the temperature can dip to around 192°F after one shot.
• 😀 The speaker aims to maintain a brewing temperature around 198°F, depending on the type of coffee used.
• 😀 The group head thermometer reading helps the speaker decide when to start the shot, ensuring it’s at the correct temperature.
• 😀 The speaker waits until the group head thermometer reaches 198°F before pulling the shot for ideal flavor.
• 😀 Monitoring the temperature with multiple indicators helps the speaker maintain precision and avoid temperature fluctuation, ensuring optimal espresso extraction.

Q & A

What is the purpose of the PID controller in the coffee setup?

The PID controller is used to manage and regulate the heat of the boiler, ensuring a consistent and accurate temperature during brewing.

How does the thermometer sensor work in this setup?

The thermometer sensor is placed on the group head, which provides a secondary reading of the temperature, helping to monitor when the boiler has reached the desired heat level, as the sensor on the boiler may not be as accurate in relation to the actual brew temperature.

Why is there a difference in temperature readings between the PID sensor and the thermometer on the group head?

The PID sensor is located near the heating elements in the boiler, so it reads the temperature of the water inside the boiler. The group head thermometer, however, reflects the temperature of the water reaching the group head and may show a lower temperature, as it is further from the heating elements.

Why is the group head thermometer important for brewing?

The group head thermometer is essential because it indicates how close the water temperature is to the ideal brewing temperature. If the water is too hot or cold when it reaches the group head, it can negatively affect the extraction of the coffee.

What does the user mean by 'simulated coffee puck'?

The 'simulated coffee puck' refers to a thermal filter used in the machine to simulate the conditions of a real coffee puck, allowing for testing without actually brewing coffee.

How does the user determine when the boiler is at the right temperature to pull a shot?

The user waits for the temperature on the group head thermometer to reach the desired temperature, typically around 198°F, before starting the shot. The user looks for a consistent reading to ensure proper brewing temperature.

Why does the temperature drop after pulling a shot?

The temperature drops because pulling a shot of espresso uses hot water, which lowers the temperature of the boiler and the group head. It takes time for the boiler to recover and reach the desired temperature again.

What is the typical temperature range the user prefers for their espresso shots?

The user prefers their espresso shots to be brewed at a temperature around 198°F, though they may adjust this slightly depending on the coffee being used.

Why does the user avoid pulling a shot immediately after the first one?

The user avoids pulling a shot immediately after the first one because the boiler temperature drops during the brewing process, and the second shot would likely be too cold, affecting the quality of the espresso.

What role does the timer play in the shot preparation process?

The user doesn't rely heavily on a timer but instead uses the volume of liquid in the shot glass as a guide for how long to brew the espresso, indicating a more intuitive approach to pulling shots.