# Lets have a discussion on......GROUP HEADS



## 4085 (Nov 23, 2012)

Right, this is a topic that I know very little about. I can scratch the surface for sure, but thats all. So, the job of the group head is to take pre heated water and disperse it in the basket which is inside the pf which is locked by the lugs into the group. OK, why is it perceived then that one system is better than another? The E61 is often referred to as the industry standard, but part from being the first (?) why.

Why amongst lever fans, do many think that the often referred to 'Bosco' group is the zenith.

Please, anyone chip in with their two pence worth. Hopefully we will uncover some fiction as well as some truth!


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## Dylan (Dec 5, 2011)

I think it was just a matter of the e61 group not having changed much in all this time. Most other groups are based on the same ideas of thermal mass. The e61 isn't necessarily better that the other groups of essentially the same design, it's just a largely unchanged standard.

This of course excludes thinking about the more modern saturated group.


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## GlennV (Mar 29, 2013)

Group heads are a complete mystery to me. I few years back I spent way too much time building a machine with a gaggia classic group (with an embedded cartridge heater) and a pre-heat boiler (so 3 pid loops just for temperature) and a gear pump + pressure transducer for full pressure profiling. Temperature was rock solid - far better than my current Vetrano 2B. The coffee was good, certainly much better than an unmodified classic, but when I picked up an Alex E61 HX machine it blew it out of the water (on "espresso" roasts anyway) and the project now languishes in the shed. This has to come down to the group, everything else is easily controlled for. [i did miss the ability to pull decent shots from filter roasted kenyan coffees for a while, but I've now added slayer-esque flow profiling to the Vetrano to restore this.







]


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## h1udd (Sep 1, 2015)

for me its simple ... one of my machines is 45 years old, 2 of them are 20 years old and the other is a mere baby at 8 years old ..... I just want to be able to get parts for them 10 - 20 - 60 years down the line.

so I dont care if a preheat, pid, thermo stable neutron wangler is capable of making espresso 3% better in the eyes of a marketing manager ...... I just want to be able to service, repair and replace it in half a century time without trying to track down a second hand 240v neutron wave bi polar capacitor super mega conductor

industry standard all the way


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## Mrboots2u (May 10, 2013)

There are " other groups " LM saturated group ....LM mini linea design - LM weird new lever design . Slayer group .... Sage/breville model . "Decent espresso " are prototyping a new machine - not sure what their group is .

So lots out there . The e61 is only really pro Sumer Market and I will suspect decline as tech becomes more affordable and reliable .

Yep group disperses water and keeps it at the temp you want .

Rancillio had a machine that could deliver a declining temp profile for the group - not sure what happened to that

Re repairing - it's the same won't lots of products . Men used to tinker and fix cars more easily - now there is so much electronics driving things that isn't he case.

A lot of stuff isn't made to last a lifetime but that's the nature of consumerism and capitalism they been going since the 50s ....


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## Thecatlinux (Mar 10, 2014)

i guess why reinvent the wheel ,the e61 seems like a good choice when manufactors are building a machine knowing the groups track record and also knowing that there is huge market in items like baskets tampers and such . Basically when you look at home machines with an e61 group they are all following the same couple of principles and much the same .

Doesn't seem that long ago when sage machines came out bringing different refinements and advancements to the group and boy did they take a bashing but now they seemed to have earned quite a bit of well deserved respect.

to be honest ever since and being fortunate to get an L1 my journey has not so much about machines and there pros and cons, it's been more about discovering new and great flavours of coffee. And in my modest opinion and based purely on what results are achieved in the cup with very little effort .

Having said that the bonus of having a machine where the principles and mechanics of the group are so simple to understand and maintain this surely is win win situation .

And to quote the lever legend 'the easiest machine you will ever use "

Is it the zenith ? Well it ticks all my boxes that's for sure !


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## 4085 (Nov 23, 2012)

I do not think a lever machine is easier to use than a pump. I think it might be more forgiving perhaps.With a lever, your shot preparation has to be spot on in order to get the best results........having switched form a lever back to a pump, thats my experience, and before you ask, yes, I can pull shots to a high standard, or so I tying, on either


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## Thecatlinux (Mar 10, 2014)

Forgiving , yes another box ticked

shot preparation spot on ........ Is there any other way ?


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## 4085 (Nov 23, 2012)

Thecatlinux said:


> Forgiving , yes another box ticked
> 
> shot preparation spot on ........ Is there any other way ?


You want to try some of the crap I have been served from people who think they can produce decent coffee!


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## Mrboots2u (May 10, 2013)

dfk41 said:


> You want to try some of the crap I have been served from people who think they can produce decent coffee!


We all have different ideas of decent coffee


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## malling (Dec 8, 2014)

Dfk41 you do know taste is subjective - I have gotten plenty of well made shots I defined as crap - someone who doesn't know better might find a badly prep shot decent

But there are more interesting groups out there then the classic e-61 - personally I always preferred the elektra over the e61


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## 4085 (Nov 23, 2012)

I am not sticking up for the e61...and believe me, I know all-out taste being subjective........I am referring to people who think they produce good coffee and get it wrong on number of levels........ @jeebsy do you think your coffee is better, now you have had the benefit of preparing and selling


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## jeebsy (May 5, 2013)

dfk41 said:


> I am referring to people who think they produce good coffee and get it wrong on number of levels........ @jeebsy


Dunno if that association is a good thing....

I don't know if my coffee is better, dialling in etc is all the same process you do at home but my workflow and stuff has improved a lot


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## Xpenno (Nov 12, 2012)

In my opinion groups are designed to provide two main functions

1. Maintain a stable temperature

2. Disperse, pressurise and push water through the coffee puck

Leaving levers to one side for a moment, for point 2 I think most groups that work on a pump are quite similar from what I've seen. They might have to ability to alter flow using restrictors or other devices but generally they all do the same thing whether they are an E61 or a Saturated Group type.

The most important for me is point 1 and this is where the saturated style group improves thing over the E61, for me at least.

The E61 maintains temperature by circulating water from the boiler to keep the block at the desired temp. Water then passes through a series of pipes to the group and out the shower. The problem with this is that you can end up with pretty big temperature variances and even with a decent flushing ritual it's still not always bang on. Another smaller downside is that you have to keep the boiler temp a good 10-15c hotter than you want the temp at the group.

When using a Saturated group (LM etc..) the head is built-in to the boiler so your group is effectively the same temp as your boiler. To add to this the pipes that supply water to the coffee puck run from inside the boiler through the water that is keeping the group warm and then directly onto the coffee. Using this method you are able to maintain a much more consistent temperature at the puck as the pipes holding the water are never exposed to the elements and the boiler water is closer to the desired brew temperature.

Levers are a completely different beast as you are effectively dumping water onto the coffee and then pressurising it with the lever mechanism. When the water leaves the boiler it is hotter than the desired brew temp but cools as it hits the group and continues to do so during the shot. These help give a lever it's distinctive flavour profile.

I'm not sure that you could directly compare groups designed for pump machines against those designed for lever however I don't know too much on the subject.


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## risky (May 11, 2015)

Curious to see where things go with more manufacturers trying something different. Goodness knows it took long enough with grinders for companies to move away from the traditional design.

'If it ain't broke...' seemed to be the industry mantra.

http://www.mavamespresso.com/ etc etc. more and more companies moving away from E61 design and the like. Choice is a good thing.


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## Xpenno (Nov 12, 2012)

risky said:


> Curious to see where things go with more manufacturers trying something different. Goodness knows it took long enough with grinders for companies to move away from the traditional design.
> 
> 'If it ain't broke...' seemed to be the industry mantra.
> 
> http://www.mavamespresso.com/ etc etc. more and more companies moving away from E61 design and the like. Choice is a good thing.


The new San Remo at host has new groups designed from the ground up. They have a boiler in the group then a normal brew boiler and then a massive steam boiler. Supposed to be really stable.

When I was down at Prufrock in London they wanted to see wider baskets i.e. wider than 58mm to see if extraction could be more even.

Lot's of stuff going on, just slow/expensive progress I guess


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## risky (May 11, 2015)

Xpenno said:


> The new San Remo at host has new groups designed from the ground up. They have a boiler in the group then a normal brew boiler and then a massive steam boiler. Supposed to be really stable.
> 
> When I was down at Prufrock in London they wanted to see wider baskets i.e. wider than 58mm to see if extraction could be more even.
> 
> Lot's of stuff going on, just slow/expensive progress I guess


Wider baskets is a really interesting idea! In theory it does sound like that would promote a much more even extraction.


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## Xpenno (Nov 12, 2012)

risky said:


> Wider baskets is a really interesting idea! In theory it does sound like that would promote a much more even extraction.


Yeah I agree, I wondered if it would be possible to create a PF and basket that allowed this on a standard group but it's well out of my ability (i.e. requires some skill).


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## Thecatlinux (Mar 10, 2014)

I agree I think it is difficult to compare a pump driven machine to a lever .

My opinion is only based around the end result in my cup, and what my perception of what I think is a good cup.

lots of other factors have changed my thoughts on coffee this year and my taste and preference have also changed .

I guess I might be biased towards the lever but to be honest it has fulfilled anything that I thought may have been missing , I enjoyed my time with the rocket and its e61 group , I really did .but in comparison and for me I found that a pump machine would be more sensitive to change thus making consistency (although possible) a little bit more finicky .

perhaps my perception within my coffee journey has changed and maybe it's just a coincidence its when a lever turned up .


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## Thecatlinux (Mar 10, 2014)

E61 when you think about it is quite a clever solution


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## hotmetal (Oct 31, 2013)

Soence's post #14 was very informative, cheers for that.

I don't know enough about the different group designs to have an opinion one way or the other. Thinking about the wider baskets though (#16) makes me wonder: for a given dose (say 18g), a wider basket is going to mean a thinner puck. Is this not the very thing that makes getting consistently good results from the single baskets harder, and more sensitive to perfect prep? Just wondering.

Always up for learning new stuff and there's no shortage on this forum!


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## ATZ (Aug 4, 2017)

As I continue my coffee journey and consider my next machine this is something that has me interested. Some great info on this thread.

So...

Those of you with experience of different group types (e61/saturated/lever), what was your preferred type and why?


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## xpresso (Jan 16, 2018)

risky said:


> Wider baskets is a really interesting idea! In theory it does sound like that would promote a much more even extraction.


Wider baskets makes for a narrower layer of product (Coffee) and fluid will always take the easiest route, personally I feel it would find an easier route through a narrower layer.

I'm not suggesting a 25mm filter, but as someone suggested 'If it aint broke dont....'.

Jon-Willy


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