How to factor pre-infusion into espresso extraction times?

Beginner and pro baristas share tips and tricks.
MattHowell

#1: Post by MattHowell »

My Breville Barista Express has a built in 10 second pre-infusion.
If I start my timer when I flip the pump on, should I shoot for a 30-40s shot to account for the 10s pre-infusion?
OR
Should those pre-infusion seconds count for less since the pump isn't at full pressure?

Hopefully my question makes sense. Thanks!

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RapidCoffee
Team HB

#2: Post by RapidCoffee »

MattHowell wrote:Should those pre-infusion seconds count for less since the pump isn't at full pressure?
Good question, been asked many times before, no definitive answer. You can
1. count PI as part of the extraction time
2. ignore PI in the extraction time
3. do something in between (e.g., Jim Schuman has advocated splitting the difference, i.e. counting half the PI time)

Since acquiring a DE1+, I've learned a lot about preinfusion. Regardless of pump pressure, it takes several seconds to saturate the puck. Until then, there is essentially no resistance to flow from the puck, and puck pressure is close to zero. If you increase PI time (by reducing pump pressure/flow rate), it changes the extraction characteristics (flow rate will increase). Extraction under pressure is perhaps the key defining feture of espresso, so these days I generally record PI time and (high pressure) extraction time separately.

The good news: there is nothing magic about a 25-30s extraction, it just happens to work well for classic Italian espresso. Experiment with different extraction times and choose whatever gives you the best results in the cup.
John
★ Helpful

MattHowell

#3: Post by MattHowell »

John,
Thanks for the thorough reply! That is kinda how I've been approaching it in my head.
I've played around quite a bit, and with the profile the BE runs, I've found the least bitterness/most sweetness between 34 & 36s when pulling at a 1:2 ratio (and including PI in my shot time). My main purpose in asking the question was more to better communicate espresso recipes to friends.
Thanks again!
- Matt

Tonefish

#4: Post by Tonefish »

Never counted preinfusion in shot time. Always tried for 25 to 30s shot after preinfusion. In fact the primary purpose for preinfusion for me was to provide a more full bodied ristretto shot with the finer grind allowed due to the preinfusion.
LMWDP #581 .......... May your roasts, grinds, and pulls be the best!

Bluenoser
Supporter ♡

#5: Post by Bluenoser »

I don't think one number can convey much accuracy or information. Maybe say extract to 30-35 seconds with vibe pump and no PI. Extract to 25-30 seconds with 5 sec PI. I don't find a single range that useful since PI can cause significantly different flow rates through the puck.

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another_jim
Team HB

#6: Post by another_jim »

John's answer is where I stand now too, with one small exception. If you do very long preinfusions on third wave coffees, i.e. 20 to 40 seconds, then it becomes something different from just preparing the puck; it becomes more like steeping the coffee in a French press. Think of a profiling espresso machine as a high tech dripper, where you can steep the coffee for a while, then let it percolate. Extreme profiling is the high pressure version of that.
Jim Schulman

mathof

#7: Post by mathof »

I record the pre-infusion time and the pour time separately. That way I know what I have done, and can return to it or modify it on subsequent shots. In this case, two numbers are better than one.

MattHowell

#8: Post by MattHowell »

another_jim wrote:John's answer is where I stand now too, with one small exception. If you do very long preinfusions on third wave coffees, i.e. 20 to 40 seconds, then it becomes something different from just preparing the puck; it becomes more like steeping the coffee in a French press. Think of a profiling espresso machine as a high tech dripper, where you can steep the coffee for a while, then let it percolate. Extreme profiling is the high pressure version of that.
That's a helpful way to think about it. Thanks Jim!

MattHowell

#9: Post by MattHowell »

mathof wrote:I record the pre-infusion time and the pour time separately. That way I know what I have done, and can return to it or modify it on subsequent shots. In this case, two numbers are better than one.
Pardon my ignorance, but I'm not seeing the point of recording the two times when using a machine like mine that doesn't offer modifiable PI times. Thanks

Bluenoser
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#10: Post by Bluenoser »

I feel I can do a somewhat modified PI on a vibe by turning on for about 2-3 seconds then returning lever to Centre neutral position for x seconds. X being PI time then raise to complete shot. Usually my pressure gauge doesn't raise above 2 bar.