Can an espresso filter change a brew?

I recently saw an advert for a machined espresso filter. I have always wondered how you can tweak and espresso machine, and seeing this is quite interesting. Can the size of the holes make that big a difference?

Well read what coffee geek had to say: (original link Can These Filters Change the World of Espresso?) Here is a summary.

Driven by an idea in a lecture VST redesigned the fitler basket to produce their own one, producing three different basket sizes. But it's not just the physical size of these baskets that are different: the holes, their size and placement are given extreme attention for each individual basket size. The four sizes are: :

• 7 gram basket (still in development, not yet available);
• the 14 gram basket (VST will call this a 15g basket, as it can hold 14-16g);
• the 17 gram basket (VST ref 18g - can hold 17-19g);
• and the 21 gram basket (VST ref 22g, holding 21-23g).

1. One of the things learned was the value of around 1-2mm separation (depending on the type of coffee used, but leaning towards 2mm) from the top of the bed of coffee and the bottom of a dispersion screen. For many testers, this was deemed the optimum clearance to allow for full and complete saturation of the bed of coffee. The vertical depth of each basket is designed with this 2g max swing in weight while still hitting desired target extractions as shown with an ExtractMojo refractometer test and Mojo's Brewing Control Chart.
2. Water flow through the bed of coffee was also exhaustively examined. Existing baskets, with a much smaller exit surface area vs a larger entry area on top for liquid often result in uneven, sometimes unpredictable extractions. The answer would be to maximize the bottom flat portion of the basket, with as many holes as possible to the edges. This is one thing the VST baskets do.
3. Other baskets have inconsistent holes sizes, and this produces grinds in the espresso and blockages, so the VST baskets solve this through a patent-pending (and protected) manufacturing and testing process. Where most baskets have a wide spread of sizes for holes (sometimes as many as 200 different hole sizes in one filter), the VST baskets, by contrast, 3 to 5 hole size spread for almost every exit hole in the filter. They are just that uniform, and that leads to better, more even extraction possibilities.

The baskets do make a difference, but the also expose bad tamping techniques


Update:
Okay so they are not VST porta filter baskets but while in Seattle I picked up the Strada ones, one getting home, and making sure my tamp was correct, I was really surprised how a small difference can change so much, the espresso was much better extracted, crema at least 50% better, and the espresso tasted good.

So if you cannot lay your hands on the VST porta filter baskets, then try a La Marzocco agent and ask for their baskets. They really do improve the expresso you can pull.