June 15, 2016

IMS vs VST: Espresso Baskets and Their Effects on Extraction

Espresso baskets: they’re small but mighty. And so, despite their critical impact on extraction, they’re often overlooked.

In fact, it was little more than half a decade ago that Vince Fedele of VST first unleashed his precision baskets on the coffee world – years after other advances in specialty coffee equipment, such as PID-controlled multi-boiler machines to saturated groupheads, had been made. Yet over the past several years, attitudes towards espresso baskets have been changing.

And today, we have a new challenger brand in town: IMS. So how do IMS rank against VST? Well, I decided to put them both to the test in a blind tasting with a range of basket sizes. Read on to discover which baskets won.

SEE ALSO: Espresso Machine Mods: 4 Reasons to Use a Naked Portafilter

IMS espresso baskets

Who’s Who in the Espresso Basket Scene

While VST were revolutionary, they weren’t the first to offer superior baskets to what arrived with your espresso machines. Synesso baskets, for instance, were always highly regarded. However, VST were the ones that fully investigated the effects of geometry, hole diameter, and shape on extraction and then offered a filter with a guaranteed consistency of hole placement and shape.

Prior to this, most baskets had serious design flaws. Hole sizes varied wildly – some were big enough to allow particles to pass through into the espresso, while others so small that they were easily blocked, all in the same basket.

What’s more, the geometry of these baskets usually wasn’t optimised for an even extraction: the exit surface area was often significantly smaller than that of the entrance, resulting in a less-than-ideal flow of water through the puck.

And so, for several years, the VST baskets reigned supreme. You’ll hear occasional complaints from some baristas that they’re unforgiving, but the general consensus (and my own opinion) is that good distribution and tamping can eliminate these problems.

However, a new brand has recently moved onto the scene: IMS. This Italian company has been producing metal products for the espresso industry since shortly after World War 2. And now they’ve launched a new range called Competition Filters, which they claim offers the same advantages as VST baskets.

It’s time to put that to the test…

espresso shot

Don’t underestimate the power of a good basket.

Testing VST and IMS Baskets: The Methodology

We ran a variety of espressos through the baskets for the blind tastings, including a Rwandan Cyanika from Colonna Coffee and a Tanzanian Hasambo Peaberry from RoundHill Roastery. Both coffees were relatively lightly roasted but correctly developed.

Grinding duties were undertaken by an EK43 with coffee burrs and the espressos were extracted using our Kees Van der Westen Mirage, which runs heavy flow restriction and low pump pressure (6.5 bar). Brew ratios were chosen to optimise each bean, but were kept constant across baskets sizes and manufacturers.

Another thing we had to pay attention to is grind size. Something we’ve known for a while now is that grind fineness needs to be changed when moving between different basket sizes. This may seem obvious, as larger baskets contain more grounds which then slow down extraction, but the variance in hole diameter between different basket sizes should, in theory, compensate for this. In reality, the 15g baskets required a grind 1 notch finer, on the EK’s scale, than the 18g ones to maintain the same brew ratio in the same time.

Interestingly, there was also a significant variance in the fineness of grind required when comparing identically sized VST and IMS baskets. The IMS baskets needed a grind setting 1–1.5 notches finer than their VST counterparts in order to achieve the same results. We concluded that this was probably a result of hole diameter but, as measuring something so small was beyond our capabilities, this is only a suspicion.

coffee grinder

The setup for our test.

Taste the Difference: The Results of Our Test

Well, taste-wise, there was a general preference for the IMS baskets. These were noted as producing a touch more sweetness and a little more delicacy in the cup. However, it should be noted that these differences were very slight. In fact, they would almost certainly be undetectable in a milk-based drink.

One possible explanation for the tasters’ preference for the IMS baskets is that they require a greater grind fineness for the same espresso, in terms of brew ratio, doses, and time, than the equivalent VST filters. This may result in greater grind evenness, since at finer grind settings, the two main peaks of particle distribution are likely to be closer to each other. But yet again, this is only supposition.

However, there is one issue with the IMS baskets: with some light roasts and the smallest double basket (15g), we reached the limits of the EK’s grinding fineness. This is unlikely to be a problem on  conventional espresso grinders, but is something to bear in mind if you use coffee, rather than Turkish, burrs on your EK.

IMS also produce a single-sized basket, fittingly called The Single, which is specifically designed to produce a single shot at the same grind setting as a double basket. In practice, at least with our coffees, they necessitate a small adjustment coarser to maintain the same flow rate as an equivalent double. However, they do seem to result in better-tasting espresso than we normally achieve by splitting a double using a spouted portafilter.

The Winner of the VST-IMS Tests

Based on our – admittedly fairly limited – taste testing, the IMS filters have a small edge in taste over those from VST. This difference is slight, though, and much less pronounced than the differences between either manufacturers’ products and one of the crudely stamped filters that many espresso machines still ship with.

So which one is better? Ultimately, it comes down to the individual and how well the basket works with your equipment.

But either way, it’s exciting to see more high-performing espresso basket producers enter the marketplace. I’m sure this will lead to even greater innovation and improvement.

All views within this opinion piece belong to the guest writer, and do not reflect Perfect Daily Grind’s stance. Perfect Daily Grind believes in furthering debate over topical issues within the industry, and so seeks to represent the views of all sides.