Posted Fri Apr 29, 2011, 9:00pm Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
I contacted VST to ask if they would be willing to ship a single basket to Canada by a cheaper method like USPS First Class. As it stands, the only method they offer is UPS Standard. After shipping, brokerage, and tax, a $25 filter is almost $60.
How different is the average E61 machine from LM machines in terms of screen clearance? The important measurement is the distance from where the top of the basket sits against the gasket and the level of the screen.
Posted Sat Apr 30, 2011, 5:03am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
Bob_McBob Said:
How different is the average E61 machine from LM machines in terms of screen clearance? The important measurement is the distance from where the top of the basket sits against the gasket and the level of the screen.
Vince (GS3) and I (Speedster) compared these measurements on our respective machines. The measurements were very close.
The Speedster uses standard E61 screens and gaskets. And using the E61 system, one can get group gaskets of varying thicknesses to change this dimension if you wish. I'm not sure if this is also true on the LMs.
Posted Sat Apr 30, 2011, 7:21am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
andys Said:
Vince (GS3) and I (Speedster) compared these measurements on our respective machines. The measurements were very close.
The Speedster uses standard E61 screens and gaskets. And using the E61 system, one can get group gaskets of varying thicknesses to change this dimension if you wish. I'm not sure if this is also true on the LMs.
I just purchased one of these and I have an E61 La Valentina Auto. I just want to be clear from your post, Andy, that you have measured a negligible difference in dispersion screen clearance and that it should be fine. In other words, it should be fine, but if it isn't I may be able to adjust?
Posted Sat Apr 30, 2011, 7:34am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
Spitz Said:
I just purchased one of these and I have an E61 La Valentina Auto. I just want to be clear from your post, Andy, that you have measured a negligible difference in dispersion screen clearance and that it should be fine. In other words, it should be fine, but if it isn't I may be able to adjust?
Yes, I believe it will be fine. But if you DID want to adjust the screen clearance, you could do so by obtaining a thicker or thinner group gasket. As a test, I actually took an old gasket and made it about 1mm thinner on a belt sander. This decreased the clearance for a given dose. It didn't make a significant difference in the extraction yield, although it made the distribution of grounds in the filter more critical in order to avoid uneven pours.
Posted Sat Apr 30, 2011, 7:47am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
RapidCoffee Said:
there are grind adjustments for the different baskets, "slightly more coarse for the 22g filter and slightly more fine for the 15g filter, with the 18g filter midway in between".
I believe one of Vince's original design goals was to be able to keep the grind constant when changing from basket to basket. This proved very difficult to achieve, but he came close.
Posted Sat Apr 30, 2011, 8:10am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
andys Said:
I believe one of Vince's original design goals was to be able to keep the grind constant when changing from basket to basket. This proved very difficult to achieve, but he came close.
I can imagine it would be difficult. You would have to match open hole area (number of holes and/or hole size) to dose, and make sure this held true over a wide range of coffees, roasts, and grind settings. "Close" is an impressive achievement.
Posted Sat Apr 30, 2011, 8:26am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
samuellaw178 Said:
I don't mean to start a argument or anything. But I have a triple basket that can hold about 18g-20g that comes with my npf. To my untrained eye, the basket I have looks almost exactly the same as the one in the photos, in term of the hole sizes, straight wall, maximum holes spread etc. I wasn't really convinced that the basket is any more special though.
[disclosure: I am a VST beta tester. In this role, I got my filters free of charge. I would love to see this technology become more popular, but I have no financial interest in the company.]
There are several areas where the VST baskets may prove superior to the one you have:
Even though they look similar to the naked eye, the VST basket may be more consistent in hole area.
The VST baskets have had the hole area carefully adjusted to the intended dose, which makes it easier to get extractions in the optimum yield range and gives the most forgiving results.
The VST baskets have innovative and state-of-the-art quality control (hole area, basket dimensions, finish etc). So if you and I both have, say, a VST 18g basket, we can directly compare the results of our extractions without guesswork. Cafes can buy a dozen baskets of a given size and know they will all perform the same. With other baskets, this is often not the case.
The VST baskets are heavier duty and will perform longer without breaking. There's more metal there: a triple filter weighs about 35-36g. How much does yours weigh? Admittedly, this may not matter in home use. But in commercial duty, many similar-looking baskets fail within a short period of time.
Joel_B Senior Member Joined: 9 Oct 2007 Posts: 1,823 Location: Pacific NW Expertise: I love coffee
Espresso: Astra Mega II Grinder: Mazzer SJ, Virtuoso Vac Pot: Yama 5 cup Drip: nope, french press Roaster: Behmor, WP, BBQ drum
Posted Sat Apr 30, 2011, 10:28am Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
samuellaw178 Said:
Erm, I don't mean to start a argument or anything. But I have a triple basket that can hold about 18g-20g that comes with my npf. To my untrained eye, the basket I have looks almost exactly the same as the one in the photos, in term of the hole sizes, straight wall, maximum holes spread etc. I wasn't really convinced that the basket is any more special though.
I would agree with what mark is saying here. Getting an even pattern and consistent hole size isn't as easy as it may seem and with such small hole diameter it's not as even as it may appear to the naked eye. I do this for a living so i can tell you everything you wanted to know about metal perforation but were afraid to ask.
The holes are made not really any different than a 3 ring hole punch for a binder. You have a punch and die (you can make just about any shape, but we'll just stick with round for ease). The punch is on top of the material and the die sits underneath the material directly in line with the punch. It's important to understand that the punch and die are cutting surfaces. The punch comes down and presses (cuts) into the material. While the punch is moving thru the material the material is being cut on the bottom side by the die until the punch makes entry into the die pushing the slug (the cut material) thru the die.
This process alone doesn't produce a perfectly straight round hole. You can see this on a larger hole in thicker material, but the inside of the hole isn't perfectly smooth and isn't perfectly round. It will be rough and jagged. The whole is also tapered; it's a larger diameter on the die side compared to the punch side. The reason for this is die clearance. The die is a larger diameter so the punch will have room to move thru it. If it were a pressed fit, it wouldn't work. This also leaves a burr on the die side of the material. In case of baskets, the material is ground smooth (perhaps some other processing?) which removes the burr but it also removes some martial. Since the hole is tapered, any inconsistencies in the polishing can leave each hole a different size. Although this would be such a small variance based on the thickness of the baskets, it can technically change it.
How clean the hole is and consistent the pattern is comes down the condition of the tooling. For starters, the setup needs to be correct. This involves the proper die clearance, how well aligned the tooling is (how centered the punch is to the die) and the entry (how far the punch goes into the die). With such a small hole such as in the baskets, even very small misalignment can drastically change the quality and consistency of that hole. As the tooling is in use, the tooling becomes dull and will wear unevenly. The more wear, obviously the worse the the quality of the hole. With larger holes, every little variance isn't as noticeable or crucial as a percentage to the size of the hole, but with the size of these holes (these holes are microscopic in the world of metal perforation) the little variances are huge as a percentage to the dimension of the holes.
The other thing that can affect the pattern consistency is how much stretch happens. The material actually stretches (and unevenly at that) during the perforation process. The more stretch the harder it is to keep the pattern uniform. This also will cause the material to bubble/dome/disfigure. Mark talked in the article about the concavity of the bottom of the baskets. I'd suspect that has more to do with the material stretch than the actual forming stage of the basket.
Regarding open area percentage (how much area of all the holes combined compared to the entire area) can be calculated but is affected by numerous factors; hole diameter, hole spacing, and pattern (inline or staggered, 45deg or 60deg, etc.)
The fact that regular baskets look as good as they do is pretty amazing to me. The fact that vst has improved on it is even more so. But I have to ask, is there really that much in the cup difference to warrant nearly 3 times the cost?
MarkPrince Moderator Joined: 19 Dec 2001 Posts: 5,462 Location: Vancouver, BC Expertise: Professional
Espresso: KvdW Speedster Grinder: Compak K10 WBC Vac Pot: A bit too many Drip: Clive Coffee Drip Stand Roaster: Hario Glass Retro Roaster
Posted Sat Apr 30, 2011, 3:28pm Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
Vince also explained the taper in each hole cut is very integral to fluid dynamics. I actually can't recall too much about that discussion, but I do recall if it is a straight wall (ie, each hole has a straight, vertical surface, no taper) liquid flow will plug up.
I'd answer the last question in Joel's post by saying: the taste difference CAN be substantial. Plus as Andy pointed out, these baskets are designed for a longer use before failures. He showed me several examples of baskets that have failed under cafe use.
kevlar Senior Member Joined: 25 Mar 2008 Posts: 72 Location: Winnipeg Expertise: I love coffee
Espresso: Expobar Brewtus 3 Grinder: Vario Vac Pot: Hario Drip: Bodum French Press Roaster: Leaving that to the pros
Posted Sat Apr 30, 2011, 4:36pm Subject: Re: Can These Filters Change the World of Espresso? by Mark Prince
Ok so if these baskets will fit an E61 grouphead but one of the design parameters being that with the correct dose in each basket it leaves a defined amount of space between the top of the puck and the dispersion screen specific to a La Marzocco machine. The problem then being with an E61 grouphead that the top of the puck would be too close to the dispersion screen. Could this not be accounted for by using the 22gram basket but dosing 18-20 grams in it therefore giving you the correct spacing?
As for the problem with shipping costs to Canada, we could always get a bunch of us together for a group buy. I live not far from the border and go down to pick up coffee on a regular basis and would happily ship the orders out to everyone else.
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