Rosso Corsa wrote:(I'm aware that I can get a 58mm optional basket for my Mina, but I'm sticking with the 54mm for now...) Cheers!

You have peaked my curiosity on how this works? I would love to be able to use a 58mm on La San Marco group head!

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Discussion split off from Weber Moonraker?

JB90068 wrote:You have peaked my curiosity on how this works? I would love to be able to use a 58mm on La San Marco group head!

Hello,

It's a very simple procedure... The 58mm kit includes a 58mm IMS shower screen, a 58mm shower holding plate, a single and double 58mm basket, a back-flush disc, and a double spout portafilter. Installation is easy-peasy and does not require special tools or knowledge. Cost is around $250.00, IIRC.

I thought about getting this when I purchased my Mina, but I wanted to experience the Mina as Pablo Dalla Corte envisioned it, with a 54mm portafilter. I may well get it at some point, but I'm in no rush to do so. This kit is only for Dalla Corte machines however...

Cheers!

Dalla Corte claim that the 54mm is a better configuration, that less surface area a) promotes less channeling, and b) due to deeper puck with same amount of coffee, the water takes longer to get through it which promotes better extraction.

Would be interesting to see data on this. In the meantime, my machines have 53-54mm portafilters along with manual flow control - so I'm feeling good about my choices yet again,

I owned a DC I mostly found it to be an urban legend, I never noticed more or less channeling nor higher expectations. It's a different of 26.42cm2 vs 22.9cm2 or 13.3% difference in surface area.

The main difference is the need to grind slightly coarser, coarser grind are easier to handle (less prone to clumping) and I think this is what is the root cause of the story. However this could at large be countered by increasing surface area of the holes At bottom of the basket.

My biggest grip with 54mm is rater that your stuck in the past the best we got is an IMS 641 holes basket the 58mm has 641 or 715, VST 720ish and pullman 876 and no high precision basket with several thousand holes and many help tools is also not made in 54mm either. It's just a very limited platform and it will just further and further behind on these aspects as all are on 58mm.

The first thing I'll do would be to convert it and DC should just toss in the towel, it makes no sense insisting on something that is growingly becoming a disadvantage.

I use IMS B662T basket on my Nurri Leva. IMS B662T has 641 holes, the same as their B702TH2xM series 58mm baskets. Considering the area of 54mm basket (actually near 55mm), 641 holes are almost the same as 727 holes of VST 58.5mm basket.

I used 18g coffee grounds when I use Lelit Bianca with VST basket, and 16g on the Nurri Leva. With the same dial of my MC4, the puck thickness and the extraction time for the 1:2 ratio are almost the same. I did have less channeling on my Nurri Leva, but the machines are different. I cannot say it is resulted from the 54mm filter basket.

A 641 hole is 641 hole unless you increase the hole size and those won't have same flow as 727 all other parameters kept constant, it might cover a similar percentage of the button on a smaller basket as a VST, but not really the same as it will have same flow as a VST as it's designed for deeper puck dept and less surface area. To achieve similar shot you need to make a calculation to keep the puck dept the same or you do as it's designed for grinding coarser, it's been well known with these shallower basket to be the only workable approach, however you then have more potential headspace if you reduce the dose that introduces other challenges.

Nurri is a lever can't really be compared with none levers, my F58 is also more forgiving then the pump machines I owned that include both DC, La spaziale and some 58mm machines.

A 18g would be about 15.6g on a DC +\- 0,5g depending on basket used. However the problem is as I wrote that 54mm basket have originally been designed to be deeper puck dept.

In that you don't wanna go with 32 but 26

Can see they improved the holes of M pattern, that said they offer now a C pattern that has 715 holes but only 58mm

malling wrote:A 641 hole is 641 hole unless you increase the hole size and those won't have same flow as 727 all other parameters kept constant, it might cover a similar percentage of the button on a smaller basket as a VST, but not really the same as it will have same flow as a VST as it's designed for deeper puck dept and less surface area.

I didn't say the flow rates are the same, but the extraction times to the same 1:2 brew ratio are the same. It is similar to you put different diameter test tubes in the rain for the same time, all the tubes will have the same water depth, but the water volume in each tubes are different. That is, the average flow rate of each hole of the VST and IMS B662T baskets are almost the same. As the basket holes to the surface area ratios, puck thickness, and coffee ground coarseness are the same, the puck resistances for the brew water are the same. I think the result is reasonable.

I don't think the smaller diameter baskets are designed for deeper puck depth. They just make the puck deeper with the same grams of coffee beans, so you have to grind coarser to compensate, but how many grams you use is up to you.

bakafish wrote:I didn't say the flow rates are the same, but the extraction times to the same 1:2 brew ratio are the same. It is similar to you put different diameter test tubes in the rain for the same time, all the tubes will have the same water depth, but the water volume in each tubes are different. That is, the average flow rate of each hole of the VST and IMS B662T baskets are almost the same. As the basket holes to the surface area ratios, puck thickness, and coffee ground coarseness are the same, the puck resistances for the brew water are the same. I think the result is reasonable.

I don't think the smaller diameter baskets are designed for deeper puck depth. They just make the puck deeper with the same grams of coffee beans, so you have to grind coarser to compensate, but how many grams you use is up to you.

DC specifically mentioned deeper puck dept I quote

Secondly, in the 54mm portafilter the coffee cake will be taller than the one in a 58mm portafilter with the same amount of grounded coffee in the filter: the water will flow through the puck more slowly and with far less pressure, extracting more flavors and aromas for a richer espresso.

It would be the only rational reason (from a marketing perspective) or else smaller are a disadvantage as you would then be forced into smaller pulls. If you hold the 54 DC basket in hand you would know how tall these are so yes deeper pucks where part of the reason for the narrow basket.

The other reason they mentioned is the puck experiences 30kg less pressure but it's a bit of a different debate.

The last part you wrote you basically just wrote what I wrote so we don't disagree all that much there.

malling wrote:DC specifically mentioned deeper puck dept I quote

Yes, I know that, but DC is not the basket designer. Besides, why do you need to follow it? VST also has different depth of baskets. No one said you should use specific grams of coffee in the basket.

malling wrote:Nurri is a lever can't really be compared with none levers,

Is there some sort of supernatural inhabitation of lever machines that prohibits the comparison or something?

Ultimately this is about pushing hot water through ground coffee. If the constraints that produce the pressure are identical and the temperature is identical, it matters not whether the source of power for water flow is a human arm, a spring, or a mechanical pump. One could perhaps quibble and say a vibratory pump, with its pulses, is slightly different... but even that is unlikely.

This is not like we're comparing apples to oranges. We're comparing machines that make small cups of black coffee to machines that make small cups of black coffee.