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PostPosted: Tue Dec 09, 2014 3:32 pm
by simonp
dr.chris wrote:You know they use cyanide to leach gold dont you?


Not leaches then? :lol:

Of course there are loads of people who swear pre-infusion has no benefit, but I will go with my own experience. when I don't let a little bit of water in first I get a less even pour. It could be coincidence but it is very repeatable if so...

PostPosted: Tue Dec 09, 2014 3:48 pm
by dr.chris
simonp wrote:
dr.chris wrote:You know they use cyanide to leach gold dont you?


Not leaches then? :lol:

Of course there are loads of people who swear pre-infusion has no benefit, but I will go with my own experience. when I don't let a little bit of water in first I get a less even pour. It could be coincidence but it is very repeatable if so...


Leaches would be a lot more environmentally friendly I guess. Dont want to think about how you get the gold out of the leaches though.

I would have thought if you have a good even grind of coffee, a nice even tamp and a good machine that delivers a nice even pressure on top of the puck then you wouldnt necessarily notice any difference with preinfusion or not. I just suspect that preinfusion makes it easier and also allows more control during extraction.

(And if there are any coffee machine manufacturers out there who want some computational modelling work done....)

PostPosted: Tue Dec 09, 2014 3:58 pm
by simonp
dr.chris wrote:a good machine that delivers a nice even pressure on top of the puck then you wouldnt necessarily notice any difference with preinfusion or not.


I suspect that few machines actually manage this perfectly due to the dispersion screen etc so this could be where the benefit comes with an E61 group.

PostPosted: Tue Dec 09, 2014 4:36 pm
by simonp
Hmm, a little concerned about my new ebay purchase:
http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a482b23a6

as I've just noticed the apparently same grinder has been sold by the same seller on ebay twice before:

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a45f817fb

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a458f796b

Looks a bit suspicious to me :(

PostPosted: Tue Dec 09, 2014 4:41 pm
by dr.chris
If you look at it the other way around without pre infusion.

The puck will be resistant to flow and you are suddenly applying water and a big pressure. The water wants to find a path into the puck.

If there is any variation in resistance on the surface of the puck (uneven tamp/ ground distribution) then that is going to affect where the water goes.

As soon as the water starts to penetrate into the puck it becomes easier for more water to take that route because the conductivity increases with saturation. Where the water goes next will depend on how the grounds are distributed through the puck but even if you get an even distribution of flow out of the bottom you may end up with areas at the top of the puck which stay relatively dry.

If the top of the grounds are wet then the wetting front will find it easier to penetrate the top layer of the puck and the pressure distribution (and flow) should be much more even.

PostPosted: Thu Dec 11, 2014 7:29 pm
by CakeBoy
GreenBean wrote:
dr.chris wrote:... but I am an expert on using leaching to extract metals, such as gold...

CakeBoy wrote:I need a Nescafé! :)

I need to know how to leach gold from used coffee pucks :wink:


Nescafé Gold Blend? :roll: :oops:

PostPosted: Thu Dec 11, 2014 7:32 pm
by CakeBoy
simonp wrote:Hmm, a little concerned about my new ebay purchase:
http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a482b23a6

as I've just noticed the apparently same grinder has been sold by the same seller on ebay twice before:

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a45f817fb

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a458f796b

Looks a bit suspicious to me :(


Hopefully he has a batch of ex-lease or similar and everything is above board. At least one person has left feedback for one of these, and the seller has been around a few years. Fingers crossed!

PostPosted: Fri Dec 12, 2014 8:36 am
by GreenBean
CakeBoy wrote:
GreenBean wrote:
dr.chris wrote:... but I am an expert on using leaching to extract metals, such as gold...

CakeBoy wrote:I need a Nescafé! :)

I need to know how to leach gold from used coffee pucks :wink:


Nescafé Gold Blend? :roll: :oops:

So the options are cyanide or Nescafé Gold Blend. I am not sure that I would feel safe working with either. :wink:

PostPosted: Fri Dec 12, 2014 8:38 am
by GreenBean
CakeBoy wrote:
simonp wrote:Hmm, a little concerned about my new ebay purchase:
http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a482b23a6

as I've just noticed the apparently same grinder has been sold by the same seller on ebay twice before:

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a45f817fb

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a458f796b

Looks a bit suspicious to me :(


Hopefully he has a batch of ex-lease or similar and everything is above board. At least one person has left feedback for one of these, and the seller has been around a few years. Fingers crossed!

I will keep my fingers crossed too, Simon. Please let us know what you think after it arrives.

PostPosted: Fri Dec 12, 2014 11:54 pm
by simonp
GreenBean wrote:
CakeBoy wrote:
simonp wrote:Hmm, a little concerned about my new ebay purchase:
http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a482b23a6

as I've just noticed the apparently same grinder has been sold by the same seller on ebay twice before:

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a45f817fb

http://www.ebay.co.uk/itm/Fiorenzato-F5 ... 2a458f796b

Looks a bit suspicious to me :(


Hopefully he has a batch of ex-lease or similar and everything is above board. At least one person has left feedback for one of these, and the seller has been around a few years. Fingers crossed!

I will keep my fingers crossed too, Simon. Please let us know what you think after it arrives.


After several pokes I did get a message from the seller with a screen shot of tracking info, shame it was too low resolution to read the tracking number :roll: They said they were too busy to contact me before. Coz it takes so long to do...
As mentioned though the feedback looks legit. So hopefully it will arrive next week.
I also bought some new burrs (best to start fresh) from a different ebay seller but they seem very slow to send too. Ho hum.

I'll report back what I think of the grinder in comparison to the Mini which I will probably sell if the new purchase is good.

PostPosted: Sat Dec 13, 2014 1:43 am
by CakeBoy
Let's hope it all goes well.

PostPosted: Tue Dec 16, 2014 1:55 pm
by simonp
CakeBoy wrote:Let's hope it all goes well.


All here present and correct! What a beast... it's kinda big...

All looks in good condition. Shame the main on-off swict broke the first time I pressed it :roll: I think it was just a random failure and not like it when the seller sent it. Luckily a standard £2 rocker switch will sort it.
I bodged in a temporary swicth to fire it up and all seems OK, quiet bearings, running true etc. Grinds beans though a bit slow so I reckon the burrs are worn, luckily I pre-empted this and ordered new ones which have just come now. Just need to find some time to swap those, wait for the switch to arrive, run some cheapo beans through to season and thn try some shots on Sunday probably :D

PostPosted: Tue Dec 16, 2014 3:23 pm
by CakeBoy
Thank goodness! Good news apart from the switch. Maybe extremes of temperature during transit on an old brittle switch? As you say, no major hassle. At least it arrived amidst what appears to be general chaos in the delivery systems since Black Friday. Let's hope it proves to grind decently. Fingers crossed for Sunday :)

PostPosted: Tue Dec 16, 2014 4:54 pm
by simonp
CakeBoy wrote:Fingers crossed for Sunday :)

And fingers crossed that the wife doesn't kill me when she sees it :shock:

PostPosted: Wed Dec 17, 2014 12:37 am
by CakeBoy
simonp wrote:
CakeBoy wrote:Fingers crossed for Sunday :)

And fingers crossed that the wife doesn't kill me when she sees it :shock:


True, but if the worst comes to the worst you at least wouldn't need to worry about the switch anymore! A real win win situation :wink: :shock: