The ECM Synchronika II represents a sophisticated approach to home espresso brewing, offering both traditional E61 pre-infusion capabilities and advanced pressure profiling options that rival commercial equipment. Understanding these features is essential for maximizing extraction quality and unlocking the full potential of your coffee beans.
Understanding E61 Group Head Pre-Infusion
The Foundation: Built-In E61 Pre-Infusion
The Synchronika II’s E61 group head features an ingenious pre-infusion system that operates automatically with every shot. The E61 has built-in pre-infusion, in the lower chamber of the group there is a preinfusion chamber and while this fills the pressure to the coffee puck is lower, providing a gentle introduction of water before full brewing pressure is applied.
How E61 Pre-Infusion Works:
- Initial Water Entry: When the E61 lever is moved up to the brew position, the pump starts and fills the chamber above the infusion valve and then begins to pre-infuse the coffee in the portafilter
- Pressure Buildup: The pre-infusion chamber gradually fills, allowing water to contact the coffee grounds at reduced pressure (typically 2-4 bar)
- Valve Activation: When pressure reaches 4-6 Bar (controlled by the infusion valve spring), the infusion valve opens, transitioning to full extraction pressure
- Flow Restriction: Hot water from the boiler passes through the water inlet to several chambers and then the portafilter. To do so, it must go through narrow pipes, further restricting the flow
This built-in system provides approximately 3-5 seconds of gentle pre-infusion before transitioning to the main extraction phase, creating more even water distribution and improved extraction uniformity.
Advanced Pressure Profiling with Flow Control
Optional Flow Control Integration
The ECM Synchronika II is a German dual boiler, rotary pump, E61 espresso machine with a built-in PID and shot timer that can be direct plumbed or run on its built-in reservoir. Control your extractions with our built-in flow control device! The optional flow control system transforms the Synchronika II into a pressure profiling powerhouse.
Flow Control Mechanism
The flow control device works by restricting water flow from the rotary pump to the group head, allowing precise manipulation of extraction pressure throughout the brewing process. This iteration of the ECM Synchronika comes equipped with a Flow Control device, allowing you to directly control the flow rate of your extraction. This flow profiling offers an extra layer of experimentation that can unlock the potential of your coffee beans.
Pressure Profiling Techniques and Applications
Basic Pressure Profiling Workflow
Phase 1: Extended Pre-Infusion (0-15 seconds)
- Start with flow control valve at 10-25% open
- Allow water to saturate coffee grounds at 1-3 bar pressure
- Watch for even wetting across the entire puck surface
- Duration varies based on coffee freshness and grind size
Phase 2: Pressure Ramp (15-20 seconds)
- Gradually increase flow control to 50-75% open
- Monitor pressure gauge as it climbs to 6-8 bar
- Adjust speed based on coffee’s response and desired flavor profile
Phase 3: Full Extraction (20-30+ seconds)
- Open flow control to 75-100% for main extraction
- Maintain 9 bar pressure for optimal extraction
- Fine-tune based on flow rate and taste preferences
Advanced Profiling Strategies
Declining Pressure Profile (Lever Machine Mimicry): A lever machine might have full pressure at the outset of the shot, and reduce the flow as the shot nears completion. Different beans and roast techniques will react to different flavour profiles that can be generated by controlling the amount of water flow at different times throughout the pulling of your shot
- Start with flow control at 100% (9+ bar pressure)
- Gradually reduce to 75% mid-extraction
- Finish at 50% for gentle finale
Blooming Profile (Light Roast Optimization):
- Ultra-low flow (10-15%) for 10-15 seconds
- Allow visible coffee bloom and CO2 degassing
- Rapid ramp to full pressure for extraction
Coffee-Specific Applications
Light Roasts: Benefit from extended pre-infusion (10-15 seconds) at low pressure to allow proper degassing and even saturation
Medium Roasts: Standard ramping profile works well, with moderate pre-infusion (5-8 seconds) before pressure buildup
Dark Roasts: Shorter pre-infusion (3-5 seconds) to prevent over-extraction of bitter compounds
Single Origins: Extended pre-infusion helps highlight unique flavor characteristics and terroir
Blends: Balanced pressure profile maintains consistency while highlighting complementary flavor notes
Technical Specifications and Capabilities
Pressure Range and Control
- Maximum Pressure: 9+ bar (rotary pump capability)
- Pre-Infusion Range: 1-4 bar (E61 natural pre-infusion)
- Flow Control Range: 0-100% flow modulation
- Precision: Stepless flow adjustment via needle valve design
Integration with OLED PID System
The Synchronika II builds on ECM’s legacy by adding exciting features like an OLED PID display with navigation knob and cartridge heaters in the E61 group, providing real-time feedback for pressure profiling optimization.
The OLED display shows:
- Current extraction pressure
- Shot timing
- Temperature readings
- Flow rate indicators (when equipped with flow control)
Comparing Pre-Infusion Methods
Natural E61 vs. Flow Control Pre-Infusion
Natural E61 Pre-Infusion:
- Automatic and consistent
- 3-5 second duration
- 2-4 bar pressure
- No user intervention required
Flow Control Pre-Infusion:
- Fully customizable duration
- Variable pressure control (1-9+ bar)
- Requires active user manipulation
- Infinite profiling possibilities
Practical Benefits
Improved Extraction Uniformity: Pre-infusion ensures complete ground saturation before high-pressure extraction begins
Enhanced Flavor Development: Pre-infusion. This refers to the process of gently soaking the puck of ground coffee in your portafilter before applying the full desired brewing pressure, allowing for optimal flavor compound extraction
Reduced Channeling: Gradual pressure application minimizes pathways through the coffee puck
Bean Adaptability: Different pressure profiles can optimize extraction for various coffee characteristics
Optimizing Your Pressure Profiling Setup
Equipment Considerations
- Use a precision scale for consistent dosing
- Invest in a quality grinder for uniform particle distribution
- Consider a pressure gauge portafilter for real-time feedback
- Maintain consistent tamping pressure and technique
Environmental Factors
- Water temperature stability (crucial for consistent extraction)
- Ambient humidity effects on coffee grounds
- Bean age and degassing considerations
- Grind size adjustments based on profiling technique
Documentation and Refinement
- Record successful pressure profiles for different coffees
- Note timing, pressure points, and taste outcomes
- Adjust profiles based on seasonal coffee changes
- Share findings with the home barista community for feedback
Troubleshooting Common Pressure Profiling Issues
Over-Extraction Symptoms
- Bitter, harsh flavors
- Dry mouthfeel
- Solution: Reduce pre-infusion time or pressure, coarsen grind
Under-Extraction Symptoms
- Sour, sharp flavors
- Thin body
- Solution: Extend pre-infusion, increase pressure during extraction
Uneven Extraction
- Mixed flavor notes (sour and bitter simultaneously)
- Solution: Focus on pre-infusion technique and puck preparation
Final Analysis
The ECM Synchronika II’s dual approach to pre-infusion and pressure profiling—combining automatic E61 pre-infusion with optional flow control—provides unprecedented control over the extraction process. For those seeking even more control, the Synchronika II is compatible with an optional flow control device, allowing for pressure profiling during the brewing process. Whether you rely on the consistent, built-in E61 pre-infusion or dive deep into custom pressure profiling, understanding these capabilities transforms your home espresso experience from routine to extraordinary.
Mastering these features requires patience, experimentation, and careful attention to coffee variables, but the reward is café-quality espresso that showcases the unique characteristics of every bean you brew. The Synchronika II doesn’t just make espresso—it provides the tools to craft truly exceptional coffee experiences.