# Cherub pre-infusion



## fatboyslim (Sep 29, 2011)

I know there are quite a few Cherub owners on the forum now so I just thought I'd share something fun.

Yesterday I accidentally started pulling a shot just as the auto fill kicked in. This may have happened to others in the past but seeing as how I was using a naked PF I saw the whole thing.

The first few glimpses (of golden brown heaven) had just started to appear from the basket when the auto-fill kicked in, at which point these droplets held in place for a few seconds. The autofill then switched off and the shot continued as normal.

This was also very nice even pour, suggesting some kind of pre-infusion.

I know its a bit fiddly but if I can find a way to successfully incorporate auto-fill sequence into pulling a shot I'm pretty sure we can have pre-infusion on a Cherub


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## CamV6 (Feb 7, 2012)

Hmm, interesting.

I once tried to do a pre-infusion by switching on brew for about 3 seconds then off again just before any coffee started to poke through the bottom of the basket (also using NPf) waiting a second or two and then back on brew again for the rest of the shot.

It didnt work. Indeed it was aweful and pished everywhere running fast fast and channeling like crazy. Maybe I just got unlucky with an exceptionally bad dose/tamp on that occasion, but even my worst dose/tamp would never come out like that so i doubt it.

Spent half an hour cleaning all local surfaces. Decided not to try again.

I can vaguely recall autofill kicking in half way through a shot but that that was a long time ago and I wouldnt have had the knowledge/experience/realisation to pay attention to how it impacted on the pour.

Makes perfect sense that since the pump is now either totally or partially employed for the boiler (actaully thinking about it, surely it can only pump to one location or the other since the cherub works on solenoids?) and that it would have that effect.

It might be simpler than it first seems to deliberately replicate that again. I find that autofill always comes on after you have drained somewhere between a half/full (tea) mug of water from the outlet. I'd therefore imagine the way to try it is to prep as normal, put a mug under the outlet, put the PF in the group head as if to pull the shot, but before doing so open the outlet and switch on brew just as you get to 1/2 way full in the mug.

I may well make a decaff later so if i'm not too dim or lazy to remember I'll give it a go and report back.

BTW, you know the naff silver painted plastic water tank cap? I found a great way to improve that. Sainsbury's do a brushed alu finish airtight jar and the lid is just the right size. Cut out the plastic insert from within the lid and it will now slide snugly and firmly over the water tank and look about a million times better. I'll see if i can find a link if its on their webshyte.


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## CamV6 (Feb 7, 2012)

Ok, here's a link

http://www.sainsburys.co.uk/sol/shop/home_and_garden/kitchen/kitchenaccessories/kitchen_storage/119866506_tu_stainless_steel_small_canister.html?hnav=4294901988

and this is the actual item


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## CamV6 (Feb 7, 2012)

I'm totally highjacking your thread but....

I just tried it, and I think it might work - although i must admit i totally fluked it first time! Without boring you by explaining how i came to this process, it turned out to be as follows:

1. Having ground and tamped the basket, put a tea mug under the water outlet

2. Now fix the PF in place ready to pull the shot

3. Open the water outlet until autofill starts

4. Immediately autofill kicks in turn the machine off althogether.

5. Turn Machine straight back on. Immediately hit the brew switch also.

6. The machine will recommence refill a few seconds after its turned back on. However, you have also started the brew which will just start to produce the first little blobs of coffee when autofill restarts and stops the brew.

7. Autofill stops and your shot carrries on as normal.

Now, I must say, it did run a little quick and was a little spitty but I think my grind was a little coarse. so will try it again sometime with the same beans but a slightly finer grind. Having said that the double shoot itself was very hice, had a slightly darker crema than normal but still as thick a layer as normal and a slightly sweeter taste with less 'bite'.

Its not something I'd seek to make my routine as its a pain in terms of emptying the reservoir unnecessarily and I'm sure this would put more strain/wear on the machine than is sensible, but none-the-less an interesting process to play around with and get right that might yeild some appreciable benefit

Please try it yourself and let me know how you get on?


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## fatboyslim (Sep 29, 2011)

Had a few goes this morning. Mostly excellent results.

Lock PF into group, drain water from hot water tap and start shot before auto fill kicks in. First few dribbles then autofill , pre-infusion, then shot resumes. I'll try and do a video. Maybe a pre-infused vs non-pre-infused shot?

Sent from my cm_tenderloin using Tapatalk HD


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## jimbow (Oct 13, 2011)

Fascinating stuff - I will have to give it a go!

I remember a discussion on here with Mike Hag about pre-infusion on machines without an E61 leva (like the Cherub's) when he was preparing for UKBC. I believe the Cherub's group head design, like Mike's E91, incorporates a piston within the head to provide a gradual pressure ramp-up. Some pre-infusion will also occur naturally providing sufficient head-room has been left above the puck and the water debit of the machine is not too high. According to my measurements, the water debit on the Cherub is smack in the middle of the optimum range


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## sandykt (Dec 3, 2009)

CamV6 said:


> BTW, you know the naff silver painted plastic water tank cap? I found a great way to improve that. Sainsbury's do a brushed alu finish airtight jar and the lid is just the right size. Cut out the plastic insert from within the lid and it will now slide snugly and firmly over the water tank and look about a million times better. I'll see if i can find a link if its on their webshyte.


Is there any chance of a picture of this or more information? I have looked on Sainsbury's website but nothing seems to be listed. Any help, appreciated.


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## sandykt (Dec 3, 2009)

I have now seen the link earlier in the post - sorry, I really should look properly!!! Would still appreciate a picture showing the lid being used though.


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## fatboyslim (Sep 29, 2011)

New cherubs have a different and removable water tank without this plastic lid so shouldn't be an issue for you.


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## shrink (Nov 12, 2012)

my excitement level is already at max!! and no, thats not just todays caffeine intake speaking!

not sure her indoors will appreciate the size though, its not exactly small!


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## fatboyslim (Sep 29, 2011)

Did you choose stainless, custom coloured or the stock dark purple?

The shiny stainless steel is very nice to look at, sure the misses will get used to it.


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## shrink (Nov 12, 2012)

well i chose "black". for a few reasons...

1) i think it breaks up the machine and makes it look a little smaller, both me and her prefer the black to the rather OTT all stainless look.

2) all our other kitchen appliences are chrome/black so it'll fit in

3) it was cheaper

4) easier to keep clean, as one side of the machine will be near a cooker.

and

5) the rumour (i think from yourself) was that the black looked kinda purpley, which i would love

however, having trawled through a lot of photos, the john lewis one, which i thought was the black model, actually is called purple. So i'm not sure if the black one these days will just look properly black. Would be a shame as i liked the idea of the purple hint.


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