Portafilter size - is bigger better?

[phil]

Following on from my visit to Eeffoc's yesterday to see his new Spazio and a discussion about the merits of portafilter size standardisation, just to be provocative I thought I'd offer my thoughts on the matter:

• Firstly, I'm a senior IT consultant and so I understand the need for standards more than most.
  
• Secondly, there is a point of view that says "it doesn't matter if it's crap - as long as it's standard then that's more important than anything else".
  I don't subscribe to that point of view - I was one of the few that bought a Philips' Video 2000 video many years ago - and that machine *then* was better than any VHS machine even today.
  
• Thirdly, let's ask ourselves "why do La Spaziale use a 53mm basket for the same amount of coffee as everyone else puts in a 58mm basket?". The answer, as I understand it, is puck depth. The La Spaz guys seem to feel that a deeper puck leads to a better extraction.
  
• I have heard others suggest that deep pucks are just a recipe for over-extraction. Hmmm, maybe. As a counter-argument I'd like to suggest that those of you with a La Marzocco double basket compare it side by side with a standard basket. What do you see? Well the La Marzocco baket is squarer in cross section, but it's also slightly deeper than the standard basket IIRC. Think about that.
  
• At the end of the day the issue is shot quality. I tried a La Spaz at Peterj's place a few months ago and I got a stonking shot without even trying and without even the benefit of a top class tamper. Mound, level, knock, tamp, knock the side, re-tamp, lock and pull. Drink and go "wow, that's good". Actually Peter once sent me some of his own coffee to try, and from memory I would say that the shot on the La Spaz was better than any I ever pulled with that coffee on the Gaggia, even with a whole 250g to practice on.

So my contention is that there's definitely something going on with these La Spaz machines. One of the things is portafilter size. The other is temperature stability. I have to say that my argument is not proven by the comparison as the temperature stability could be the reason for the improvement. No doubt it contributes. Nonetheless I think we can say that the deeper, narrower portafilter isn't obviously giving a worse shot, and I'm tempted to say it gives a better one.

Disclaimer

I'm conscious that this sounds like a commercial for La Spaziale. That is not my intention. However, I am conscious that there is something very interesting about their kit, and so I think it's worth talking about on TMC.

Second disclaimer: I have a La Spaziale Lusso grinder. I think it's excellent, and it's extremely easy to keep clean too. I love it. I also paid for it in full. If I ever swap my Gaggia for a La Spaz (something I'm seriously considering) then that too will be paid for in full. Here at TMC we don't advertise and we don't take freebies. Just so as you know.

(Sorry - that last bit is an important part of who we are here at TMC, and I just want to make sure that we're clear about that).

Cheers

Phil

[Joey]

Thank you, thank you. Since months I am trying to convince everyone that deeper PFs are better.... I am really glad you brought that up. I totally agree..... and I think I have tried to explain it once but would love to do it again:
See the water drop going to an inch in high stacked coffee, and look at the one running through half an inch....who gets more in touch with coffee? No overextraction because same time of the water beeing on it's way - just touches more coffee ... stop.... gotta run, sorry, agree with Phil, rock on! Spazi and LSM rule!

[kingseven]

It'd be interesting to know how they arrived at 53mm. It can't really be practical to try everything from 60mm to 45mm can it?

Just out of curiousity - does the Spaz basket knock out a nice puck? You tend to find that standards were set a long time ago - be it brew pressure of size of handle. I have an old '50s machine sat here at work and you can take the brew handles out of it and use them in any machine today.

I like that someone is challenging the standards, but like you I'd like to know more science. I read a few scientific papers (you know, to pass the time) and they are often using special custom built espresso machines - be interested to know what sort of set up they have too.

[phil]

Yeah I'd like to know the justification for the actual size too. And as someone who was a research scientist in industry before moving into IT, it tickles my scientific curiosity. If you're going to plot a variation in characteristics with portafilter size, how exactly do you design the experiment to keep all of the other factors constant so that the results are valid? And what exactly do you measure to plot? Fascinating.

Actually I think in practice it's going to be "let's try a few different sizes and see what happens, and then choose the size that seems to be the best compromise". A sort of engineering approach.

Also let's not forget that the guys who designed the La Spaz machines originally were the same guys as designed the E61 group for Faema. I reckon they maybe knew a thing or two.

Oh and yes, the puck's nice and solid. I broke into one and it looked really even, no signs of channelling or uneven-ness.

Can you tell that I want one of these babies?

[kingseven]

Heh! There is a little lusting coming through.

The main problem with a lot of this, and it relates to Joey and her 30 second single origin pours is that we are all trying to produce a beverage (I am reminded worryingly often that "its just a cup of coffee") and taste is entirely subjective. Is it technically badly made even if it tastes good? Scientific studies use a large panel of judges, but in any panel you are going to get around 25% of those being supertasters and more sensitive to bitter aspects in the cup. Until we are able to track the motion and pathways of water through coffee then we will constantly be disagree about the best methods of extraction.

I believe temperature to be far more important in the role of extraction than basket size, because some flavours extract only at certain temperatures so with temperature control you can start to select the flavours going into your cup (in theory). The Synesso machines look interesting and I shall be keeping an eye on them (from a great distance obviously). http://www.synesso.com/

[ivdp]

A nice starting point: 53mm machines make better espress's than 58mm machines!

So now the testing: weigh the amount of grounds, fill the portafilters and pour 30cc.

Blindfold the tester and write down his findings: . . . . .

Ivo

[phil]

Quite right Ivo. Hence my comments about how you design the experiment!

Ivo's point is the same as Jim's really, and the same as the one I tried to make - it's all a subjective (I called it "engineering" ) decision.

[Joey]

A nice starting point: 53mm machines make better espress's than 58mm machines!

So now the testing: weigh the amount of grounds, fill the portafilters and pour 30cc.

Blindfold the tester and write down his findings: . . . . .

Ivo

We did:
La San Marco 1 group, 9bar, 90°C, 55mm PF
La Pavoni 1 group, 9bar, 90°C, 58mm (?or more?)PF

Ground 32gr of coffee, divided it into 2x 16gr PF baskets, let the shots run the same time, same amount of water:

LSM: full bodied, well balanced coffee flavor
LP: deffinitely thinner, the flavors where felt on the gum more then on the tounge

So in other words it was like comparing orange juice with pulp and one from concentrate.
:drink:

*nuff said. now I stop bothering everyone with my tests*
PS.: I totally agree with kingseven: the perfect taste is the desired result - no matter if it takes 23 or 32 seconds....

[Ian]

PS.: I totally agree with kingseven: the perfect taste is the desired result - no matter if it takes 23 or 32 seconds....

Quite agree, I don't think there is a scientific formula for a good tasting drink.

Ian

[kingseven]

But can science be used to improved our brewing technique for a good drink?

[matts]

La San Marco 1 group, 9bar, 90°C, 55mm PF
La Pavoni 1 group, 9bar, 90°C, 58mm (?or more?)PF

Ground 32gr of coffee, divided it into 2x 16gr PF baskets, let the shots run the same time, same amount of water

Whilst I applaud the effort as a starting point there's so many other uncontrolled variables here I don't think you can really say much except it tasted a bit different. Just my 2p

Matt

[Joey]

whatelse could make the shots different? Btw, not a bit - a lot!
tamping was the same - well, not measured with a torque spanner - but still so much the same that if there was a tiny bit of pressure difference, I doubt it would have changed the taste that much.
As I said, same temperature, same pressure, same coffee same grind, same amount, same water...etc.....
....What other differences then the PF size between the Pavoni and LSM are you referring to?
I am curious.....

[matts]

....What other differences then the PF size between the Pavoni and LSM are you referring to?
I am curious.....

I'm not an engineer Joey but if you posted something like this to alt.coffee then the serious tech heads would have the methodology in pieces before you could say boo. Just off the top of my head there's water debit, extraction profile (temp changes during the shot) and I'm sure there's more.

It's an extremely difficult thing to isolate because almost by definition if you have 2 different pf sizes then you have 2 different machines/ groupheads etc and the 'taste' difference could be due to all kinds of things. How did you measure/ control the temperature for instance?

Cheers
Matt

[Joey]

How did you measure/ control the temperature for instance?

the best way is with one of these wire/thermometer thingies inside the PF, exactly mounted on the shower screen...
but that is one of the reasons I don't join alt.coffee and cg anymore, because some of these Schomer followers are getting way too anal for my taste. Nothing against Schomer - I like him, but stepping back one step I have to remind myself that I want to serve the customers a wonderful cup of coffee - and with eliminating 98% of the "mistakes" that can be made - I think I do well. These little differences you are talking about - seriously - I doubt that anyone can taste the difference if the water has 89 or 89,6 degrees.
Yes, we are all aiming for the perfect cup, but with taking care of choosing good machines, well maintenanced, freshly roasted coffee and a good tamping ritual - we are doing much for changing the coffee culture.
Where is written what degree you need for which coffee - 0,1° wise?
The point is - each of you have a different machine - if only one adjustment would be perfect, and it seams that all of you have an opinion what the perfect machine must be like - shouldn't everyone who has another machine at home be sad?
No, I don't want to argue in 0,001 ranges because I don't think they make that much differences.
The difference between the Pavoni and the LSM was huge, believe me, and surely not because one might have a 5cm longer pipe or 0,5mm thinner pipe somewhere inside......

Sorry for blaspheme, but I don't like to pick something that's actually good into pieces. I am happy that I get better coffee with a deeper PF.
That doesn't mean that there doesn't exist another machine with a flatter PF that makes also a coffee that tastes the same - so be it.

joey

[matts]

The difference between the Pavoni and the LSM was huge, believe me, and surely not because one might have a 5cm longer pipe or 0,5mm thinner pipe somewhere inside......

Sorry for blaspheme, but I don't like to pick something that's actually good into pieces. I am happy that I get better coffee with a deeper PF.
That doesn't mean that there doesn't exist another machine with a flatter PF that makes also a coffee that tastes the same - so be it.

I agree with a lot of what you say. It must be a guy thing all this analytical stuff The problem comes with the leap from 'I made better coffee with this machine with it's deeper basket' which is perfectly valid, to 'the reason for that is the deeper basket and not much else, and so machines with deeper baskets and smaller pfs are better'.

I think a lot of the smaller pf=bad thing attitude came about because some cheaper home machines used a smaller size. I'm sure in a properly designed quality machine it's not that important and a range of sizes gets you the right result.

Matt
'like Joey says it's mostly how you drive 'em '