Pre-infusion is the first part of some espresso shots
Pre-infusion is a low-pressure wetting stage before a machine moves to full brewing pressure. Breville's Infuser BES840 manual describes it as a gradual pressure increase that expands the coffee bed before the higher-pressure part of extraction. Not every machine gives the same control, and some machines do not expose a pre-infusion setting at all.
Check what your machine can control
| Machine behavior | What to record |
|---|---|
| Automatic pre-infusion | The default time shown in the manual or display |
| Breville Infuser BES840 hold-to-pre-infuse control | How long the 1 CUP or 2 CUP button was held before release to full pressure |
| No listed control | The normal shot time from pump start |
The Infuser BES840 begins full-pressure extraction when the cup button is released. Use your exact manual before changing a setting.
Use one stable shot recipe
Set a dose and target yield first. Record total shot time from pump start, including any pre-infusion. This article does not use first-drip time as a comparison value. Then change only the pre-infusion control on the next shot. Keep the grind and dose unchanged while you compare the flow.
If the result changes, record the setting and the full shot time. Do not claim that a longer or shorter pre-infusion is always better. The coffee, machine, and basket can all change the result.
For the grinder adjustment that follows a flow change, use how to dial in espresso. Light-roast espresso gives a controlled example for a lighter coffee.
Use the manual as the safety limit
Do not bypass model-specific controls or pressure limits. If a manual only describes an automatic shot, leave that setting in place and adjust the normal dial-in variables instead.
We read Breville product and manual materials on September 21, 2026. We did not physically test, own, prepare, taste, or measure this method.
Use the linked method for the next step after this task.
Continue with the related methodCommon questions
What should I check before I start?
Pre-infusion wets the coffee before full brewing pressure. Controls vary by machine; use the exact manual and record total shot time from pump start.
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