If 58 mm portafilters seem to be labeled as commercial grade/size, why do machines like the vivaldi or piston lever manual machines use much smaller diameter groups.

Does a 53mm hold the same amount of coffee as a 58mm.

Thanks, Will

I can put 18gr into the Vivaldi double baskets, no idea what a 58mm double will hold.

The word 'commercial size' is misleading since there are a couple of manufacturers (e.g. La Spaziale, Dalla Corte etc) not using the more ubiquitious 58 mm format for their 'commercial' machines. The difference in diameter being 5 (or 4) mm depending on who you ask.

As to the question why - the smaller diameters are e.g. said to be less prone to channeling than the 58mm format due to a deeper puck. The amount of coffee is independent of the diameter, you can get the same volume sized baskets for the smaller diameters too. The sizes 14g, 16g, 21g etc. are an approximation anyway as you can up or downdose any of these.

There are a couple of threads out there discussing this subject (particularly since the Vivaldi arrived), I suggest you take a look at these and do a search.

expobar-brewtus-ii-vs-la-spaziale-s1-t1020.html
how-many-grams-does-your-portafilter-basket-hold-t3765.html
changes-in-dosing-and-leveling-technique-from-58mm-to-53mm-basket-t4992.html

There are other formats out there as well, check this one out:

http://coffeegeek.com/forums/espresso/machines/10421

I'm reviving an old post but I just want to say that I've been very impressed with the smaller 53mm basket size on my new Vivaldi.

At first I was turned off by the smaller size (a "man thing" I'm told) but after using it for a week now, I've changed my mind.

The higher sides seem to reduce channeling quite a bit. Another benefit of the smaller diameter is the edges are less affected by tamper tilting. Finally, the basket diameter seems to be much more accurate than the 58mm baskets. (Half the 58mm baskets I owned left 2mm gaps around the edges).

The only down-side is the pucks are harder to knock out of the basket (further evidence of a good side seal?).

I'm using an Espro 53mm convex tamper and the fit is just perfect.

In Italy, 90% of all shots are straight single espressos pulled from a single basket. For these, the group diameter is irrelevant, since the single basket's puck area has an effective diameter of around 49mm to 51mm. Most Italian machines are primarily designed for this market, and the double basket and optimizing its behavior is not high on the engineering priorities.

That being said, I've heard some engineers (obviously working with 58mm groups) say that for doubles, the aspect ratio of a 58mm puck is optimal, while a 53mm is too narrow and deep.

My experiments of measuring the extraction at various levels of the puck show that the upper levels are more extracted than the lower levels. So the deeper the puck, the more uneven the extraction top to bottom. Given you want to extract between 20% to 25%, it seems there is a maximum proper puck depth, and going deeper will under extract the bottom and over extract the top. However, I don't know what that depth is or how other variables affect it.

To Paraphrase Rabbit:

1. An idea: One would expect the finer grinds to find their way to the bottom of the basket.
2. Thus, one would want the upper levels to extract slightly more than the lower,
3. So deeper narrower baskets are better, unless the grinder is perfect,
4. Which they aren't,
5. Which is one reason why its so easy to get good extractions with the old 43, 45 mm Italian home levers

One thing I'd like to mention is that deeper basket makes it more difficult to tamp the coffee evenly. The deeper layers of the puck can be less pressurized than at the surface. Actually i am not sure if it really matters. I had a chance to operate new Astoria machine (53 mm) and it worked (and also frothed) perfectly.

There definitely seems to be a taste difference between the 58mm (like the E-61 Anita I used) and my current 53mm (LaSpaziale Vivaldi). Which one you prefer depends a lot on your taste and what coffee you are using.

I do miss my old ridgeless basket (not available on the Vivaldi).

It would be interesting to hear a description of the taste difference by one of our "tasting gurus" in a blind back-to-back test.

Advantages of the smaller diameter basket:
1. With a reasonably deep tamper base, it is nearly impossible to do a tamp that isn't level.
2. Shots are more predictable with a higher percentage of "good" to "very good" shots.

However, in another thread, I wrote about being startled this weekend by the number of flavors that appeared in my cup from a shot made at a restaurant with a customized La Marzocco and well-trained staff (BarBambino in S.F.). This is what some call "clarity." They were using the same coffee I was using that week at home (Ecco Reserve).

So, I've ordered a bottomless portafilter and am going to tweak my technique to see what happens on my Dalla Corte (54mm).

Marshall wrote:Advantages of the smaller diameter basket:
1. With a reasonably deep tamper base, it is nearly impossible to do a tamp that isn't level.
2. Shots are more predictable with a higher percentage of "good" to "very good" shots.

With one notable exception , I tend to agree with Marshall most of the time. But I'm going to take issue with this post.

First, let me assure you that it is indeed possible to to perform a non-level tamp in a smaller diameter basket (in my case, 53mm Spaziale double basket, Bumper tamp with nice thick base). Maybe I'm just talented.

Second, the jury is still out on optimal basket size and shape. Answering this question will require a careful study performed on two otherwise-identical machines, one with a 58mm grouphead and the other with a smaller (53-54mm?) grouphead. I have not noticed any increase in predictability with a smaller diameter basket, but there are many other factors at play in my system (comparing 58mm HX to 53mm DB to 51mm manual lever).

My WAG: the 58mm grouphead standard has evolved for a reason, just like the near-universal recommendation of 9 bars brew pressure in pump machines. It's probably near optimal for the majority of current espresso machine designs.

RapidCoffee wrote:Second, the jury is still out on optimal basket size and shape. Answering this question will require a careful study performed on two otherwise-identical machines, one with a 58mm grouphead and the other with a smaller (53-54mm?) grouphead.

Actually... been done. Illy experimented extensively -- and I think at least a couple machine manufacturers have as well.

I believe it's covered in the Illy book.


Pet peeve.... assuming that just because no-one in the home barista community has tested a hypothesis or done an experiment it's never been done. Chef's Magazine drives me nuts because they never simply ask a professional any questions. Similar issue...

malachi wrote:Actually... been done. Illy experimented extensively -- and I think at least a couple machine manufacturers have as well. I believe it's covered in the Illy book.

Obvious counterargument:

Commercial Espresso Machines Tamper Sizes
Astoria - 58mm
Astra - 58mm
Aurora - 56mm
Azykoyen - 58mm
Bezzera - 58mm
Brasilia - 58mm
Bunn - 58mm
Caramali - 58mm
Cimbali - 57mm
Conti - 58mm
Dalla Corte - 54mm
Elektra - 58mm
ECM - 58mm
Elektra - 58mm
Expobar - 58mm
Expobar - 58mm
Faema - 58mm
Fiorenzato - 58mm
Futurmat - 58mm
Gaggia - 58mm
Grimac - 58mm
Isomac - 58mm
La Marzocco - 57mm
La Pavoni - 56mm
La Spaziale - 53mm
Laranzato - 58mm
Pasquini - 57mm
Rancilio - 58mm
Nuova Simonelli - 58mm
Rancilio - 58mm
Reneka - 56mm
San Marco - 53mm
Synesso - 58mm
Unic - 56mm
VFA - 58mm
Wega -58mm

Home & Semi Commercial Espresso Machines Tamper Sizes
Ascaso/Innova -57mm
Astra - 58mm
Bezzera - 58mm
Bodum Granos - 51mm
Delonghi BAR32, BAR42, BCO264B - 51mm
DeLonghi - Because portafilter sizes are not consistent, please check with the manufacturer or re-seller for your proper size.
Elektra - 58mm
Expobar - 58mm
*Francis! Francis! X1 (old model) - 53mm or 52mm
Francis! Francis! X1 (new) - 56mm
Grimac - 58mm
Krups - 49mm
La Pavoni Europiccola - 49mm
La Pavoni Millennium - 51mm
La Pavoni Professional - 51mm
La Pavoni Lusso, Pisa, Si - 53mm
La Pavoni Club Combo, Duet - 58mm
La Pavoni lever machines (mfg. 1999 and newer) - 51mm
La Pavoni lever machines (mfg. pre 1999) - 49mm
La Valentina - 58mm
Olympia Express - 49mm
Pasqini Livia - 58mm
Rancilio - 58mm
Saeco - 53mm or 52mm (53mm is reported to be a somewhat of a tight fit.)
Spaziale S1 - 53mm
*Starbuck's - 53mm or 52mm (53mm is reported to be a somewhat of a tight fit.)
*Solis - 53mm or 52mm (53mm is reported to be a somewhat of a tight fit.)
Quickmill - 58mm
VFA / La Valentina - 58mm
Wega -58mm

Not only do basket diameters differ, but basket height and shape varies widely. You really think there's consensus?

malachi wrote:Pet peeve.... assuming that just because no-one in the home barista community has tested a hypothesis or done an experiment it's never been done. Chef's Magazine drives me nuts because they never simply ask a professional any questions. Similar issue...

Peeves notwithstanding, I've read Illy (although it's been a while). If there was a compelling study on PF diameter, I've forgotten it. Unfortunately commercial manufacturers are not always generous about sharing their findings.

Come on... just because there is no standard doesn't mean that research hasn't been done.
Seriously.

It's quite obvious if you check the facts.....56mm is optimal (average of all diameters listed above).

But seriously, the fact that more fines extraction happens on the upper surfaces (and the 58mm has 20% more upper area than a 53mm) is the main reason for the difference in the cup.

As far a tilting is concerned, the 53mm will be less sensitive if you wiggle the handle a defined amount. It's not opinion, it's just geometry. It's only a small amount, so I agree it shouldn't make a big difference.

Right now, I must say I prefer the 58mm over 53mm (but only very slightly). Still, I actually own a 53mm for the time being simply because I just love the double boiler Vivaldi, and nothing else can compare at the same price. Always some compromises.

RapidCoffee wrote:First, let me assure you that it is indeed possible to to perform a non-level tamp in a smaller diameter basket (in my case, 53mm Spaziale double basket, Bumper tamp with nice thick base). Maybe I'm just talented.

No, your wrist is crooked.

malachi wrote:Come on... just because there is no standard doesn't mean that research hasn't been done. Seriously.

Love to see it. Seriously.

From Illy:

7.5.4 Cake shape
The shape of the coffee cake, determined by the filter's shape, is important when considering peculiar forms that deviate from the traditional ones, universally accepted by current coffee machines. The classical shape of the double dose is cylindrical, around 12 mm in height by 60 mm in width, the exact dimensions depending on the machine.

Yeah, that was exceptionally useful.

Marshall wrote:No, your wrist is crooked.

But my heart is pure.

Ponte Vecchio 45 mm
Caravel 43 mm

These are both lever machines and the smallest diameters I know of. They are both very easy to pull good shots on, but I've never used a 58 mm machine.

I have a 43 (Caravel), 54 (Dalla Corte) and 58 (Termazona lever). Each requires a different approach to get a good shot. This makes "readjusting" when I go from machine to machine a bit of a challenge. I can't say that I experience basket size making a whole lot of difference as far as channeling is concerned though. Overdosing the Termazona works well, wheras the Dalla Corte resists much overdosing at all. I don't have a bottomless portafilter for the Caravel. Judging by taste though it is the most forgiving in terms of grind and dosing variation. At least in my environment choosing the right technique with each size seems to be more important than the size itself.

One thing I've noticed lately from my 53mmm naked pours is the "nutation" type tamping move seems to be a much more important step than on the 58mm. Guess it has something thing to do with putting a higher tamping pressure on the edges for the more square puck.