# Shorter L1 Pre-Infusion



## aaronb (Nov 16, 2012)

So, Reiss has posted to the Londinium blog that the cause of the few people who experienced thermal instability was long pre-infusions.

The new advice is to reduce time to 3 seconds.

Has anybody tried such a short time on their L1? I've been doing ~6 secs as standard doing the 1000, 2000... thing in my head and now just do ti automatically as part of my espresso process without thinking about it, so will have to retrain myself!


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## 4085 (Nov 23, 2012)

The original advice was to pre-infuse until the first drips appear. with a lighter bean this took up to 60 seconds. I decided in discussion with Dave, that this was not right, even though the Guru said it was. I cut it down to 10 seconds and the shot quality improved. I have now cut it down to 5 seconds and cannot see much difference at all. The theory is, that the longer the water sits in the higher thee temp of the shot, I think!


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## RoloD (Oct 13, 2010)

aaronb said:


> So, Reiss has posted to the Londinium blog that the cause of the few people who experienced thermal instability was long pre-infusions.
> 
> The new advice is to reduce time to 3 seconds.


This is interesting. I've been tending to wait until I see the first drip appearing on the bottom of the basket - certainly this is a lot more than 3 seconds.

I'll give it a try - not that I've found thermal instability to be an issue.


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## coffeechap (Apr 5, 2012)

As posted on the other thread recently, the object of pre-infusion is to saturate the puck sufficient to expand it to the the shower screen, this is achieved within a few seconds , however a few more seconds and you are getting a fuller saturation. I used to pre-infuse on the Bosco for up to 10 seconds, by the Bosco doesn't have the same thermosyphon as the L1, I think that the revised pre-infusion of up to 5 seconds ( which is how the Italians do it) will be more than sufficient to archive the aim.


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## Mrboots2u (May 10, 2013)

Again does it not come down to the taste you wish to achieve in the cup ? I see where Reiss is coming from , and am sure the pre infusion guidelines will solve the " temp instability " . How much of an issue this was for the vast majority of L1 users is debatable isn't it?


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## aaronb (Nov 16, 2012)

Link to Londinium Blog

I've never waited for first drip either, I use lighter roasts so it would take too long. 6 seconds has always worked well, when I release the lever I get a good 'bite' and then first drip a second or 2 later.

Sorry dfk41 I know you did a similar thread recently and wasn't trying to copy it, more about Reiss's observations that this will stop any issues with stability of the L1.


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## coffeechap (Apr 5, 2012)

Mrboots2u said:


> Again does it not come down to the taste you wish to achieve in the cup ? I see where Reiss is coming from , and am sure the pre infusion guidelines will solve the " temp instability " . How much of an issue this was for the vast majority of L1 users is debatable isn't it?


I think the issue had come from huge doses over 20 grams as the group is really only designed for 17 grams or less, traditional dosing on these lever groups is only 14 grams as the water supply is a fixed amount. Higher dosing absorbs more water and takes longer to get to the first drip and thus affects the thermosyphon on the machine creating temp issues.

If you dose the correct amount and pre-infuse correctly, there will never be any issues.


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## Mrboots2u (May 10, 2013)

coffeechap said:


> I think the issue had come from huge doses over 20 grams as the group is really only designed for 17 grams or less, traditional dosing on these lever groups is only 14 grams as the water supply is a fixed amount. Higher dosing absorbs more water and takes longer to get to the first drip and thus affects the thermosyphon on the machine creating temp issues.
> 
> If you dose the correct amount and pre-infuse correctly, there will never be any issues.


Cool thanks for the explanation , I hadn't taken into the account people might be massively updosing. It's interesting to see how far people push equipment etc beyond recommended use, and then go it doesn't work right . Not necessarily exclusive to coffee , as example in my work we make glasses, the glasses are meant to work with BOTH eyes open . The amount of people who come in saying their vision isn't as clear if they close one eye. Errrr really, and why would you do that ?

Good that he has posted some clarification but I bet it starts the nay Sayers up somewhere on some blog .....


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## The Systemic Kid (Nov 23, 2012)

Recall, way back, on Reiss suggesting you wait until the first drips appear before pulling the shot so I followed this - at the time was dosing at 17-18grm. Problem was this was taking anything up to 20secs+ before first drips appeared - resultant shot tasted lukewarm and insipid so I gave up on this and followed my instinct for a preinfusion of no more than 5secs - haven't had any problems with this no matter what beans I use. Looking back, I think I too experienced thermosyphon stall by extending the preinfusion as Reiss points out in his recent post. At the time, I put the stall down to my poor technique and lack of lever experience.


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## garydyke1 (Mar 9, 2011)

very interesting discussion.

Away from levers - I noted in the Plough , on their Slayer , the shots run for 55-60 seconds! 30 seconds is 2-3 bar preinfusion (50% of contact time) , they dont switch on the full 9 BAR until an actual stream of pour has formed, never mind drops in the cup. **

On e61 groups with vibe pumps, 30 seconds total shot time, between 8 & 12 seconds can be preinfusion (c. 25-35% of contact time) the machine has just about ramped to 9 BAR at a similar time to the stream forming

** maybe I shouldnt be so quck to discount the merit in the FSR which we all joked about


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## aaronb (Nov 16, 2012)

OK, taking pre-infusion down to ~3 seconds instead of ~6:

-After releasing the lever it takes about 2-3 secs for first drip instead of 1-2 that I used to get with a ~6 sec preinfusion

-I've had some very good pours

-Crema is darker and more speckled (light-medium roast from HB, bottomless PF)

-Taste seems a bit more defined?


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## 4085 (Nov 23, 2012)

I am finding that with 3 seconds the drip is starting almost immediately.......no idea why of course but shots to the usual standard!


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## iroko (Nov 9, 2012)

I'll give the 3 seconds a go at the weekend.


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