Pre-Infusion: What It Is and How to Control It on Breville

Pre-infusion is one of those espresso concepts that sounds advanced but makes an immediate difference once you understand it. This brief pause at the start of extraction—wetting the coffee puck before full pump pressure kicks in—can transform channeling shots into smooth, even extractions.

Your Breville Barista Express includes automatic pre-infusion, but you can also control it manually for even better results.

What is Pre-Infusion?

Pre-infusion is low-pressure water application that saturates your coffee puck before full extraction pressure begins. Think of it as “priming” your coffee—giving it time to expand and seal any gaps before 9 bars of pressure hit.

The Science Behind It

Dry coffee grounds have air pockets between them. When full pump pressure hits immediately, water can find paths of least resistance through these gaps, causing channeling—uneven extraction where water rushes through specific spots.

Pre-infusion solves this by:

1. Filling air pockets with water
2. Allowing grounds to expand
3. Creating a uniform, sealed puck surface
4. Ensuring even water distribution

Pre-Infusion on Breville Machines

Automatic Pre-Infusion

The Barista Express includes built-in pre-infusion that activates automatically:

1. When you press the brew button, low-pressure water flows first
2. This lasts approximately 3-5 seconds
3. The pump then ramps to full pressure
4. Full extraction proceeds normally

This automatic system works well for most situations, requiring no intervention.

Why Manual Control is Better

While automatic pre-infusion helps, manual control offers:

• Longer pre-infusion times for light roasts
• Shorter pre-infusion for dark roasts
• Adjustment based on specific beans
• More consistent results once dialed in

How to Manually Control Pre-Infusion

The Manual Pre-Infusion Method

This technique extends pre-infusion beyond the automatic duration:

Step 1: Start Extraction Press and hold the single or double shot button. Water begins flowing at low pressure.

Step 2: Release After 2-3 Seconds Release the button while the pump is still in low-pressure mode (before full pressure kicks in).

Step 3: Wait 3-5 Seconds The water already in the group head continues saturating your puck under residual pressure. The pump is off, but your coffee is soaking.

Step 4: Resume Extraction Press and hold the button again. Now full pressure engages to complete extraction.

Total pre-infusion time: 5-8 seconds instead of the automatic 3-5.

Adjusting for Different Roasts

Light Roasts: Longer Pre-Infusion

• Problem: Dense beans resist extraction
• Solution: 6-10 seconds total pre-infusion
• Result: Better water penetration, balanced extraction

Medium Roasts: Standard Pre-Infusion

• Automatic setting works well
• Or try 4-6 seconds manual if channeling occurs

Dark Roasts: Shorter Pre-Infusion

• Problem: Porous beans extract quickly
• Solution: 2-4 seconds or just use automatic
• Result: Prevents over-extraction

Benefits of Extended Pre-Infusion

1. Reduces Channeling

The #1 benefit. Saturated pucks resist channeling because water can’t find easy paths—the entire surface is uniformly wet.

2. More Forgiving of Distribution Errors

Even if your grounds aren’t perfectly distributed, pre-infusion gives them time to settle and seal.

3. Better Flavor Clarity

Slower, more even extraction often produces cleaner flavors with less bitterness.

4. Allows Coarser Grinds

With extended pre-infusion, you can sometimes grind slightly coarser while maintaining proper extraction time.

Common Pre-Infusion Mistakes

Over-Pre-Infusion

Problem: Pre-infusing too long (10+ seconds) for dark roasts

Symptoms:

• Shot starts dripping before full pressure
• Over-extracted, bitter taste
• Very slow total extraction

Fix: Reduce pre-infusion time or use automatic mode

Inconsistent Timing

Problem: Different pre-infusion times each shot

Symptoms:

• Variable shot quality
• Can’t replicate good shots

Fix: Use a timer, develop consistent rhythm

Wrong Grind Compensation

Problem: Grinding much finer because shots are “too fast” after pre-infusion

Symptoms:

• Choking the machine
• Over-extracted, bitter shots

Fix: Pre-infusion and grind work together. Only adjust grind slightly after adding pre-infusion.

Pre-Infusion and Your Variables

How pre-infusion interacts with other espresso variables:

Variable	With Extended Pre-Infusion
Grind Size	Can go slightly coarser
Dose	Keep the same
Yield	Keep the same
Total Time	Will increase (expected)
Pressure	May read slightly lower

Do You Need Manual Pre-Infusion?

Try manual pre-infusion if:

• You see channeling in a bottomless portafilter
• Light roasts taste sour despite grind adjustments
• Your distribution isn’t perfect
• You want more control over extraction

Stick with automatic if:

• Your shots are already balanced
• You’re using dark roasts
• Simplicity is more important than optimization
• You’re still learning basic technique

Frequently Asked Questions

What Breville models support manual pre-infusion?

All Breville semi-automatic models allow manual pre-infusion through the button-hold-release technique. The Barista Touch and Oracle have dedicated pre-infusion settings.

How long should pre-infusion last on Breville?

The automatic setting runs 3-5 seconds. For manual control, 5-8 seconds works well for medium roasts, longer for light roasts.

Does pre-infusion reduce channeling in espresso?

Yes—this is its primary benefit. Saturated coffee creates a sealed, uniform surface that resists the channeling water would otherwise find.

Can I skip pre-infusion entirely?

Technically yes, but you’d need to modify the machine. The automatic pre-infusion is built into the pump ramp-up cycle. Most baristas find it beneficial.

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Related Guides:

• Understanding Channeling
• Pressure Too Low (Under-Extraction)
• Program Mode: Customizing Shot Volumes