June 15, 2016

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.

It was little more than half a decade ago that Vince Fedele of VST first unleashed his baskets on the world. This was years after other equipment advances were 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? 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 an espresso machine. Synesso baskets were always highly regarded. However, VST investigated the effects of geometry, hole diameter, and shape on extraction. It then offered a filter with 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, while others so small that they were blocked.

What’s more, the geometry of these baskets usually wasn’t optimised for an even extraction. The exit surface area was often smaller than the entrance, resulting in a poor flow of water.

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

A new brand has recently moved onto the scene: IMS. This Italian company has produced products for the espresso industry since after World War 2. They’ve launched a range called Competition Filters, which offer 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. This included a Rwandan Cyanika and a Tanzanian Hasambo Peaberry. Both coffees were relatively lightly roasted but correctly developed.

Grinding was undertaken by an EK43 with coffee burrs and extracted using a Kees Van der Westen Mirage. This runs heavy flow restriction and low pump pressure (6.5 bar). Brew ratios were chosen to optimise each bean but were kept constant across basket sizes and manufacturers.

Another thing we had to pay attention to is grind size. Grind fineness needs to be changed when moving between different basket sizes. This may seem obvious, as larger baskets contain more grounds which extraction. The variance in hole diameter between basket sizes should compensate for this. In reality, the 15g baskets required a grind 1 notch finer than the 18g ones to maintain the same ratio and time.

There was significant variance in grind fineness required when comparing VST and IMS baskets. The IMS baskets needed a grind setting 1–1.5 notches finer than their VST counterparts for the same results. We concluded that this was a result of hole diameter. As measuring something so small was beyond our capabilities, it’s 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 produced a touch more sweetness and a more delicacy in the cup. These differences were slight. In fact, they would almost certainly be undetectable in a milk-based drink.

An explanation for the preference for IMS baskets is that they require a finer grind for the same espresso. This is in terms of brew ratio, doses, and time with the equivalent VST filters. This may result in greater grind evenness. At finer settings, the two 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, we reached the EK’s grind fineness limits. This is unlikely to be a problem on conventional espresso grinders. It’s something to bear in mind if you use coffee rather than Turkish burrs.

IMS also produce a single-sized basket, fittingly called The Single, It’s specifically designed to produce a single shot at the same grind setting as a double basket. In practice they necessitate a small adjustment coarser to maintain the same flow rate as an equivalent double. However, they result in better-tasting espresso than normal by splitting a double using a spouted portafilter.

The Winner of the VST-IMS Tests

Based on our taste testing, the IMS filters have an edge over those from VST. This difference is slight and much less pronounced than the differences between either manufacturers’ product. It’s also less pronounced than with one of the crudely stamped filters many espresso machines ship with.

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

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 seeks to represent all sides.