Instructions for setting the brewing temperature - dual circuit without PID

1. Understanding the basics

• Dual-circuit principle: The machine has a main boiler for the steam (steam generates pressure) and a heat exchanger (HX) for the brewing water. The brewing water is passed through the heat exchanger and heated by the boiler.
• Temperature control: The brewing temperature is controlled indirectly via the boiler pressure. A higher boiler pressure means a higher brewing temperature.

2. Tools and materials

• Pressure gauge (if not installed)
• Geisinger-Thermometer or Scace temperature gauge (optional, for precise measurement)
• Screwdriver (if adjustments to the pressostat are necessary)
• Stopwatch or timer
• Ground coffee (for testing)
• Cup or container

3. 3. Safety instructions

• Switch off the machine when working on the boiler or pressostat.
• Avoid contact with hot surfaces and steam.
• Be careful when adjusting the pressostat as it is under pressure.

4. Adjustment procedure

A. Checking the boiler pressure

1. Check the pressure gauge:

   • Look at the boiler pressure on the machine's pressure gauge. Typical values are between 1.0 and 1.5 bar.
   • A pressure of 1.2-1.3 bar corresponds to a brewing temperature of around 92-94 °C in most machines.

2. Interpret the values:

   • A higher boiler pressure (e.g. 1.4 bar) means hotter brewing water.
   • A lower boiler pressure (e.g. 1.0 bar) means cooler brewing water.

B. Adjusting the boiler pressure

1. Switch off the machine and allow to cool down.

2. Adjust the pressostat:

   • Open the machine (if the pressostat is not externally accessible, follow the manufacturer's operating instructions).
   • Locate the pressostat (usually a small, cylindrical switch with a screw).
   • Turn the screw:
     • Clockwise: Increases the pressure and therefore the brewing temperature.
     • Counterclockwise: Reduces the pressure and therefore the brewing temperature.
   • Only make small adjustments (e.g. 1/8 turn).

3. Switch on the machine and heat up again. Check the new pressure on the pressure gauge.

C. Test the brewing temperature

1. Carry out a “cooling flush”:
   
   • With dual-circuit machines, the water in the heat exchanger can build up and overheat.
   • Briefly run water through the brew group (approx. 100 ml) before brewing an espresso.
2. Test the espresso temperature:
   
   • Brew a test espresso and check the taste.
   • Alternatively, you can use a thermometer to measure the temperature of the water flowing out of the brew group.

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5. fine tuning

• Repeat steps B and C until the desired brewing temperature is reached.
• Test different settings with your preferred coffee, as each type reacts to different temperatures.

6. additional tips

• Flush timing: The water temperature in dual-circuit machines drops after a cooling flush. Experiment with the length of the flush to find the perfect temperature.
• Note maintenance: A calcified machine can make the temperature inaccurate. Descale regularly.
• Limited precision: Without PID, temperature control is less precise. Work with small pressure adjustments and test step by step.

Guide to Adjusting the Brewing Temperature on a Dual-Boiler Machine with PID

1. Understanding the Basics

• PID Control: The PID (Proportional-Integral-Derivative) controller precisely regulates the boiler temperature by accurately switching the heating element on and off.
• Dual-Boiler Principle: The main boiler maintains water temperature for steam and the heat exchanger. The brewing water is heated as it passes through the heat exchanger (HX) using the boiler's heat.

2. Tools and Materials

• Geisinger-Thermometer or Scace temperature gauge (optional, for precise measurement)
• Ground coffee for test shots
• Timer or stopwatch
• Container or cup

3. Safety Instructions

• Always handle the machine with care, as it is hot and steam can escape.
• Changes to the PID menu should only be made according to the manufacturer’s instructions.

4. Procedure for Temperature Adjustment

A. Checking Current PID Settings

1. Check the PID Temperature Display

   • Observe the current temperature on the PID display. This usually refers to the boiler temperature, not the direct brewing temperature.
   • The boiler temperature typically ranges between 105–125°C, depending on the desired brewing temperature.

2. Verify Reference Values

   • The brewing temperature in the group head is slightly lower than the set boiler temperature.
   • Example:
     • Boiler temperature 120°C → Brewing temperature ~93°C
     • Boiler temperature 115°C → Brewing temperature ~90°C

B. Adjusting the Brewing Temperature

1. Modify the PID Temperature

   • Access the PID menu. The operation varies by machine, but typically there are buttons to increase or decrease the temperature.
   • Increase or decrease the temperature in small steps (1–2°C) and test the effect.

2. Consider Cooling Flushes

   • Even with PID machines, water in the heat exchanger can overheat.
   • Perform a short flush (approx. 50–100 ml) to remove overheated water before brewing an espresso.

C. Pulling Test Shots

1. Prepare an Espresso

   • Brew a test shot using your preferred coffee.
   • Observe whether the brewing temperature results in the desired taste (e.g., bitterness or acidity due to incorrect temperature).

2. Fine-Tuning

   • Adjust the PID temperature if the taste is not yet optimal.
   • Typical recommendations:
     • Higher brewing temperature (~93–95°C): For dark roasts, less acidity.
     • Lower brewing temperature (~88–91°C): For light roasts, more acidity.

D. Optional: Measuring the Temperature

1. Precision Measurement

   • If you have a Scace device or thermometer, you can accurately check the temperature of the water coming from the group head.

2. Comparison with PID Settings

   • Compare the measured temperature with the set temperature. If there are significant deviations, calibration may be necessary.

5. Tips for Optimization

• Adjust Preinfusion: Some PID-controlled machines allow preinfusion time adjustments, which can influence taste.
• Check PID Parameters: Some machines let you adjust PID parameters (P, I, D). Change these only if you have clear instructions or notice sluggish or unstable behavior.
• Routine Usage: Maintain a consistent routine (e.g., flush duration, heat-up time) for consistent results.

6. Common Challenges

• Taste Issues:
  • Too much bitterness: Lower the temperature slightly.
  • Too much acidity: Increase the temperature slightly.
• Inconsistencies:
  • Ensure the machine is fully heated (at least 20–30 minutes).
• Boiler Temperature: Some machines display the boiler temperature on the PID, while others show the water temperature. Check the manual to avoid confusion.

Guide to Adjusting the Brewing Temperature on a Dual-Boiler Machine Without PID

1. Understanding the Basics

• Dual-Boiler System:

  • One boiler for steam (steam boiler).

  • A separate boiler for brewing water (brew boiler), allowing for more precise temperature control.

• Temperature Control Without PID:

  • Brewing temperature is regulated via mechanical thermostats, pressurestats, or fixed resistors.

2. Tools and Materials

• Geisinger Thermometer or Scace temperature measuring device (optional, for precise measurement)

• Screwdriver (if adjustments to thermostats or pressurestats are needed)

• Ground coffee for test shots

• Container or cup

• Timer or stopwatch

3. Safety Instructions

• Turn off the machine when working on electrical or mechanical components.

• Be cautious, as high temperatures and pressure may be present.

4. Procedure for Temperature Adjustment

A. Checking the Current Brewing Temperature

1. Fully Heat the Machine:

   • Wait at least 45–60 minutes for the boilers to reach operating temperature.

2. Measure the Temperature:

   • Run water through the brew group and measure the temperature with a thermometer.

   • Alternatively, pull an espresso shot and assess the taste to infer the brewing temperature.

B. Adjusting the Brewing Temperature

1. Check and Adjust the Thermostat:

   • Most dual-boiler machines without PID have a mechanical thermostat on the brew boiler.

   • Open the machine (if necessary) and locate the thermostat on the brew boiler.

   • Turn the adjustment screw of the thermostat:

     • Clockwise: Increases the brewing temperature.

     • Counterclockwise: Decreases the brewing temperature.

   • Make small adjustments (e.g., 1/8 turn) and check the temperature after each change.

2. Fixed Resistor System (if applicable):

   • Machines with fixed temperature levels (e.g., controlled by resistors) may require resistor replacement to change the temperature. This should ideally be done by a technician.

3. Leave the Steam Boiler Unchanged:

   • Only adjust the brew boiler settings. The steam boiler is controlled separately and does not directly affect the brewing temperature.

C. Pulling Test Shots

1. Prepare an Espresso:

   • Pull a test shot with your preferred coffee and evaluate the taste.

   • Typical issues:

     • Bitter taste: Brewing temperature too high → Slightly lower the thermostat.

     • Sour taste: Brewing temperature too low → Slightly raise the thermostat.

2. Fine-Tuning:

   • Repeat thermostat adjustments until the desired temperature is reached.

D. Observing Temperature Behavior

1. Check for Consistency:

   • Test the temperature after multiple shots to ensure it remains stable.

   • Fluctuations may be caused by aging or scaling of the thermostat.

2. Cooling Flush (if necessary):

   • Some dual-boilers without PID may overheat slightly. A short flush can help stabilize the temperature.

5. Optimization Tips

• Thermal Inertia:

  • Mechanical thermostats respond more slowly than PID systems. Allow time to test the effects of your adjustments.

• Regular Maintenance:

  • Scaling in boilers or thermostats can lead to temperature deviations. Regular descaling is recommended.

• Minimizing Heat Loss:

  • Flush the brew group before brewing to compensate for heat loss.

6. Common Challenges

• Inconsistency:

  • Mechanical thermostats may be less precise. Professional calibration by a technician can help.

• Aging Thermostat:

  • If the thermostat no longer responds reliably, replacement may be necessary.

• Fluctuating Pressure:

  • Ensure the machine's water pressure remains stable, as pressure and temperature are interconnected.

Guide to Adjusting the Brew Temperature on a Dual Boiler Machine with PID

1. Understanding the Basics

• Dual Boiler System:

  • Brew Boiler: Ensures precise temperature control for brewing water.
  • Steam Boiler: Generates steam and hot water independently of the brew boiler.

• PID Control: A digital control system that enables precise and stable temperature regulation by intelligently adjusting the heating power.

2. Tools and Materials

• Geisinger thermometer or Scace temperature measurement device (optional, for precise readings)
• Ground coffee for test shots
• Container or cup
• Timer or stopwatch

3. Safety Precautions

• The machine and its components can get hot – handle with care.
• Changes to the PID menu should be made according to the manufacturer’s instructions.

4. Steps to Adjust the Brew Temperature

A. Checking the Current PID Settings

1. Read the PID Temperature:

   • Check the temperature displayed on the PID screen. This usually reflects the brew boiler temperature.
   • Typical values:
     • Brew Boiler 90–96 °C: Depending on the desired brew temperature and coffee roast level.
   • Note that the actual brew water temperature at the group head may be slightly lower due to heat loss through the piping.

2. Consider Reference Values:

   • Depending on the machine model, the PID temperature may match the actual brew temperature exactly or vary slightly. Consult the user manual for precise information.

B. Adjusting the Brew Temperature

1. Change the Temperature on the PID Controller:

   • Use the buttons or dials on the PID display to set the desired temperature.
   • Increase or decrease the temperature in small steps (e.g., 1 °C) to test the effects.
   • Typical brew temperatures:
     • 88–91 °C: For lighter roasts with more acidity.
     • 92–95 °C: For medium to dark roasts.

2. Allow the Machine to Heat Up:

   • Wait until the machine reaches the new set temperature. The PID will regulate this automatically, but it may take a few minutes.

C. Pulling Test Shots

1. Prepare an Espresso:

   • Brew an espresso using your preferred coffee.
   • Observe taste and extraction:
     • Too bitter: Lower the temperature slightly.
     • Too acidic: Increase the temperature slightly.

2. Fine-Tuning:

   • Adjust the temperature further until the desired taste is achieved.

D. Optional: Checking the Temperature

• Measure the Temperature:
  • Run water through the group head and measure the temperature with a thermometer.
  • Alternatively, pull an espresso and assess the taste to infer the brew temperature.

5. Additional Tips

• Use Preinfusion:

  • If your machine has preinfusion settings, experiment with different durations. A longer preinfusion can enhance espresso flavor, especially for lighter roasts.

• Maintain a Consistent Routine:

  • Flush the group head before brewing (a short flush) to minimize temperature fluctuations.

• Ensure Proper Heating Time:

  • Make sure the machine is fully heated (at least 45–60 minutes) before testing settings.

• Separate Steam Boiler Settings:

  • Only adjust the brew boiler temperature, as the steam boiler operates independently.

6. Common Challenges

• Inconsistent Taste:

  • Check if the coffee is fresh and the grind size is correct. These factors often have a greater impact on flavor than temperature.

• Thermal Loss:

  • Ensure the group head is hot enough, as it affects the brew water temperature.

• Maintenance:

  • Scale buildup or dirt in the machine can cause temperature fluctuations. Regularly descale and clean the machine.