Does pre-infusion time count?

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by blutch »

I just got the new Crem ONE Infuser and it's my first machine. It has what they call "GPF" "Gentle Pre Infusion." You can set the amount of time for pre infusion. I have mine set to 5 seconds. Don't ask me why, I'm just trying it. I prefer dark roasts and am using a medium-dark Ethiopian Yirgacheff Washed I roast myself for drip and pour overs. It's seems to be working well so far, but I really don't know the difference between "ok" and "excellent."

I don't have a good espresso grinder yet, so I'm not dialed in yet, but because this machine has a shot timer that starts the second you flip the lever, I am wondering if the pre infusion time counts when you are calculating the time for the shot? For now, I'm using 18 in and 42 out and it is taking around 30 seconds total. Is this really 25 seconds?

I realize that pre infusion is not really needed for dark roasts, but I didn't see the harm in having it on 5 seconds.

Thanks for helping a newbie. :)


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BaristaBoy E61

#2: Post by BaristaBoy E61 »

I measure and count line level preinfusion time with all shots as it reveals info about grinder setting for fineness that is used in my grinder adjustment calculus for the next shot.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

blutch (original poster)

#3: Post by blutch (original poster) replying to BaristaBoy E61 »

I'm not sure what "line level" is. When they say you want your shot to be "18g in and 36g out in 25 - 35 seconds" does that include the pre-infusion time or is it just once the coffee starts flowing?

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#4: Post by MNate »

If your preinfusion is just beading up the bottom surface of your puck, then right, I wouldn't count it. Just start counting from when the drips start really hitting the cup (a random first doesn't count). That gives you something better to compare with others.

However, I'd say record all the info you can if it's a variable you could tweak. So if you're working through a 5# bag of something that 5 sec preinfusion could be changed to a 10 second... did that make a difference? No preinfusion? 20 second? It's probably not the first variable you tweak (and maybe for your type of beans you just always keep it at 5 sec, which I think is a fine amount for darker roasts), but someday you may want to play with it with a different bean or a bean you just aren't satisfied with.

If it's a variable you can adjust, record it.

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#5: Post by spressomon »

Generally, when folks talk about shot time its just the time after pre-brew/infusion from the first drop to the finished shot of espresso. Even for some medium roasts, I have been experimenting with pre-brew times in the 25-30 second range, until first drop and getting great results. I have a couple different "medium" roast beans I've pulled all spring where I pre-brew until 12-15 grams in cup (18g dose, 18g VST basket) then full brew to 30grams in cup, then back to pre-brew until 28-seconds has passed (from first drop in cup) which generally yields 38-42 grams of espresso; total shot time is right at a minute. Super sweet.

The entire notion of blooming the grounds in pour-over circles has been well established for years. For some weird reason, the same benefit to espresso brewing has taken much longer to be adopted...but it all makes sense (to me at least :wink: )
No Espresso = Depresso

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BaristaBoy E61

#6: Post by BaristaBoy E61 »

blutch wrote:I'm not sure what "line level" is. When they say you want your shot to be "18g in and 36g out in 25 - 35 seconds" does that include the pre-infusion time or is it just once the coffee starts flowing?

'Line Level' is Preinfusion with Water Line Level pressure - before the pump engages, if your machine is Direct Plumbed as is ours.

For me, even though I measure time, as in Preinfusion, Pump 'ON' and 'Post Infusion' (back to 'Line Level') before ending the shot and 'Total Time' what really counts the most is weight. Weight of ground coffee in portafilter and weight of espresso in the cup. I 'Time' everything but Kill the shot based on weight that is the Ratio between coffee in portafilter and espresso in the cup that I'm looking for.

Time is just an indicator factor for future (next cup) grinder adjustment.
The attached pic is of the Stop Watch function on my iPhone. Lap 1 is Line Level Preinfusion Time, Lap 2 is Pump 'ON' Time, Lap 3 is Post Infusion Time (Back to Water Line Level Infusion) before killing the shot, 'Total Time' is displayed on the Clock Face.

I can tell just looking at the Clock Times that this was probably a pretty good shot and the grinder needs no further adjustment - even though I have no direct recollection of this shot as it was pulled Jan. 4, 2021.


"You didn't buy an Espresso Machine - You bought a Chemistry Set!"


#7: Post by erik82 »

I measure both as PI influences how fast the shot runs afterwards. If you grind and dose the same and PI for 5s or 15s your shot time will be much shorter with the 15s PI. That's a way to enlarge extraction level, grind extremely fine and PI very long (say 30-60s) to not choke your espressomachine.

This way you can find the exact combination which works best for your machine, grinder and type of beans.


#8: Post by slaughter »

I do have the same question here but in any post I have seen I never saw an obvious reply. E.g. my local roaster has a recipe for their roasts

Espresso recipe
In: 19gr
Out: 36-37gr
Time: 26sec

It is easy to get the in and out but what about the time. Do I have to count the 5 seconds pre infusion I added ? Or the 26 sec is the actual pump on time?

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BaristaBoy E61

#9: Post by BaristaBoy E61 replying to slaughter »

I believe that we each have to define what works best for ourselves. That there are no hard and fast rules or 1-universal rule or truth. We each have to define our own 'truths'. That this 'truth' is a moving target and an ever developing story that changes as we learn more with more time spent making espresso drinks.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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#10: Post by Nunas »

The only thing that counts is whether you like the espresso. Experiment with preinfusion times, soaking, temperature, grinder calibration and so on (one at a time) until you find what works for you.
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