Blooming Espresso
Blooming espresso: Scott Rao’s technique of pre-infusing the puck, pausing to let it soak, then extracting. How it works, how to try it and what it changes.
Contents
What is blooming espresso?
Blooming espresso is a way of pulling a shot with a pause in the middle. You pre-infuse the puck with water, stop and let it soak, often for around 30 seconds, then apply pressure and extract. Scott Rao created his Blooming Espresso profile in late 2018 on the Decent espresso machine, aiming for a more even extraction.
At a glance
- Grind
- Fine
- Difficulty
- Advanced
- Origin
- Global & Modern
- 2018
Method
Prep as for espresso
Dose, distribute and tamp as you would for a normal espresso.
Pre-infuse
Run water gently into the puck at low pressure until it's saturated and the first drops appear.
Pause to bloom30 s
Stop the flow and let the puck soak. Scott Rao's original profile paused for 30 seconds.
Extract
Bring the pressure back up and run the shot to your target weight.
Taste and adjust
Adjust the grind as usual, one step at a time.
Blooming espresso is a way of pulling an espresso with a pause in the middle. First you pre-infuse the puck with water at low pressure. Then you stop and let it soak, the bloom. Only then do you bring the pressure up and extract the shot. The coffee consultant Scott Rao created his Blooming Espresso profile in late 2018 on the Decent espresso machine, aiming for a more even extraction. Here’s how it works and how to try it.
The short version
- Pre-infuse, pause, then extract.
- The pause is the bloom: Scott Rao’s original profile paused for 30 seconds.
- The aim is a more even extraction, by letting the whole puck wet first.
- You need control over the water: an adjustable machine, a lever or a manual press.
- Created by Scott Rao in late 2018, on a Decent DE1.
How does blooming espresso work?
In a normal shot, water goes in and pressure builds straight away. Scott Rao argues that pre-infusion alone doesn’t fully saturate the grounds, so some of the puck is still dry when the pressure arrives. In a blooming shot you:
- Pre-infuse gently until the puck is saturated and the first drops appear.
- Pause while the puck soaks: the bloom.
- Extract, bringing the pressure back up and running the shot as normal.
Rao reported that blooming raised extraction by about 1–1.5% and made it more even. An independent study of puck resistance on Coffee ad Astra found that even a 10-second pause after pre-infusion changed how the puck resisted the water, which its author put down to the puck not being fully wet without it.
Scott Rao’s original profile
Rao’s published Blooming Espresso profile on the Decent DE1:
| Stage | What happens |
|---|---|
| Pre-infusion | Water at about 4 ml per second and 98°C, for up to 25 seconds |
| Bloom | Flow and pressure pause for 30 seconds |
| Extraction | Flow ramps up and holds at about 2.2 ml per second |
He later moved to a pressurised bloom in his “Best Practice” profile, keeping a little pressure on the puck during the pause. He says the low-pressure bloom can work brilliantly but carries more risk of channelling when the pressure comes back.
How do you try it at home?
You need a way to stop the water after pre-infusion:
- A machine with adjustable pre-infusion or flow control can be set to pause.
- A lever espresso machine lets you control when the full pressure arrives.
- A manual espresso press lets you stop pressing, wait, then press again.
Prep the puck as usual, pre-infuse until the first drops, pause, then extract to your target weight.
How long should the bloom be?
Rao’s original profile used 30 seconds. He has said two minutes is adequate for use in a café, that longer blooms are only slightly better, and suggests experimenting with much longer blooms at home.
General guidance only. Espresso machines run at high pressure and temperature, so always follow the instructions for your machine.
Blooming espresso vs other shots
- Espresso: the classic shot, without a pause.
- Turbo shot: a fast, coarse modern style.
- Soup shot: a very long modern style.
- Lever espresso: a machine that makes pausing easy.
Explore every pressure method in the pressure chapter.
What you’ll need
Words in this guide
- Bloom
- The bloom is the first small pour of water in a brew, usually 2–3 times the weight of the coffee, followed by a 30–45 second pause.
- Extraction
- Extraction is the process of water dissolving flavour compounds out of ground coffee.
- Channelling
- Channelling happens when water finds an easy path through the coffee bed instead of flowing evenly through all of it.
Questions & answers
What is blooming espresso?
A shot with a pause. You pre-infuse the puck with water, stop and let it soak, then apply pressure and extract. The pause is the bloom.
Who came up with blooming espresso?
The coffee consultant and author Scott Rao created his Blooming Espresso profile in late 2018, a few months after getting a Decent DE1 espresso machine, which can control pressure and flow precisely.
Why bloom an espresso?
Scott Rao says pre-infusion alone doesn't fully saturate the grounds, and that pausing lets the puck wet evenly, which makes the extraction more even. He reported it raising extraction by about 1–1.5%.
Can I bloom espresso without a Decent machine?
You need some control over the water: a machine with adjustable pre-infusion, a lever machine, or a manual espresso press lets you pause after pre-infusion. On a basic pump machine, it's hard to do.
How long should the bloom be?
Scott Rao's original profile paused for 30 seconds. He has also said longer blooms are slightly better, and suggests experimenting at home.
Sources
- Best practice espresso profile. Scott Rao
- Advanced mode on the DE1+. Scott Rao
- How the Decent evolved to make delicious espresso easier. Scott Rao
- Espresso: preinfuse, then pause, then extract. Home-Barista
- A study of espresso puck resistance and how puck preparation affects it. Coffee ad Astra
General guidance only. Not medical, food-safety or professional advice. Always follow your equipment's own instructions.