Varia VS4 reviewed: lots of innovation, one retention problem

The Varia VS4 was one of the most highly anticipated grinders of the last few months. When we first held it in our hands at a coffee trade show, we were blown away. Now, the full review is behind us: we spent almost half a year putting two Varia VS4s through their paces. We didn't want to make any mistakes and wanted to confirm our findings on a second grinder. It costs $499 directly from the Varia online shop, it's just under 500 euros here, and in terms of size, it sits between the smaller VS3 and the larger VS6. A 53 mm conical burr set, a brushless motor, and once again a genuine single-dosing grinder. The question we've been following for months: Does the VS4 live up to the hype, and what's going on with its particle distribution?

Aluminum block with two real innovations

The VS4 stands on the counter like a compact block of aluminum—weighing just over 5 kg, nearly 10 cm wide, 33 cm high, and 16 cm deep. It feels high-quality and sits solidly on our test bench. Included now is a 58 mm dosing cup; with the VS3, it was still a small cup that nobody was really happy with. The new cup is high-quality but has a quirk: if you leave it on during grinding, it sinks down and its rim slides into the portafilter. We aren't fans of a rim that protrudes into the portafilter. In practice, we still hardly had any channeling around the edge because this rim is very narrow. Anyone who also uses a needle tool (WDT) to distribute the grounds can completely rule out that issue.

Two things about the VS4 really excite us. The first is the grind adjustment. It is now decoupled from the grinder body and, more importantly, from the bellows. On the VS6, the adjustment was fine and precise, but when using the bellows, you often accidentally changed the grind setting. That doesn't happen here anymore because no pressure is applied directly to the adjustment ring. It also features a scale whose indicator line points precisely to the respective setting. One line corresponds to about one to one and a half, or at worst two seconds of extraction time. It barely gets any finer than that in the home sector.

The second great strength of the design is that the grinder can be opened and cleaned with just one hand. You can take out the grinding chamber in a few seconds, brush it out, put it back in, and you're done. We don't need to talk about grinder cleaners for this model; you won't need them here. Why the ability to open the grinder so quickly is a non-negligible advantage comes up again involuntarily when discussing retention.

The burr set: 53 mm conical, slow speed

Inside, it uses a 53 mm conical burr set, driven by a 200-watt brushless motor with a planetary gearbox. You set the RPM via a dial on the side between 150 and 300 RPM in 50-step increments—a speed chosen deliberately to be slow for an espresso grinder. The grind adjustment is stepless via an internal thread with 10-micrometer resolution. Active ionization is built-in to counter static electricity, though an RDT spray bottle is still included.

Faster and more pleasant than the VS3

Varia has noticeably improved here. For 18 grams, the VS4 takes around 13 seconds. The VS3 was around 30 seconds, which is about double. That makes a difference in the morning.

Things get interesting regarding the noise level, because the numbers alone are misleading. We measure around 80 to 81 decibels (precisely: 81.5 dB at 150 RPM, 82.5 dB at 300 RPM). On paper, the VS3 was significantly lower at 73 decibels, but it sounded shrill and aggressive—a high-pitched tone lasting 30 seconds, somewhere between a bee and a circular saw. The VS4 hums deeper, more like a fast bumblebee, and sounds powerful rather than like a motor on its last legs. Subjectively, it is therefore more pleasant, even though the meter shows more decibels.

The temperature of the grounds remains uncritical. With the first unit, we measured an average of 26.9 °C, which is near room temperature; the second one ran slightly warmer at 30.4 °C. Both are well within the green range. Consistency across portions is very good, with a standard deviation of 0.08 grams.

Retention: the sore point

When it comes to retention, we struggle. With a single-dosing grinder, we want the coffee we put in at the top to come out at the bottom. For this type of design, we already consider more than 0.7 grams of temporary retention to be a lot. The VS4 has around 1.8 grams of temporary retention, plus about 0.2 grams of permanent retention, totaling around 2 grams absolute. For a single-dosing grinder, that is a poor value.

This is surprising at first, because conical burrs usually have low retention since very little stays stuck to the burr itself. The problem lies elsewhere: in the sweepers that rotate under the burr. Coffee gets stuck there, breaks off, and falls out with the next grind. We measured this, as we do with every grinder: one grind, weigh, blow out, brush out, and repeat five times in a row. After the first grind with a clean chamber, more than 0.4 to 0.8 grams remained each time.

The trick is in the design. The more permanent retention gets stuck in the sweepers, the more fresh coffee it holds back next time, and the larger the temporary portion becomes. If you ignore this phenomenon, you'll quickly have over a gram of old coffee in the chamber—in the worst case, several weeks old—which mixes into the fresh grounds. However, you can open the grinder faster than you can refill the coffee, and that is exactly what mitigates the high value.

In terms of pure throughput, the single dosing works solidly: 18 grams in, plus/minus 18 grams out. Sometimes it's 17.7 or 17.8 grams, and then you know that a little more got stuck and, naturally, part of the current coffee is still from the last grind. The coffee is therefore reliably exchanged, just with this sediment that travels along.

Operation and grind repeatability

Operation is very good. The RPM dial is on the right—switch it on, and the grinder grinds until you stop it.

Grind repeatability is a real joy. We adjusted from espresso to ristretto, then to lungo and back to espresso, and the VS4 cleanly finds its starting point again. The peak width returns practically identical at 279.4 to 277.1 micrometers. Together with the fine, decoupled adjustment, this is one of the true strengths of this grinder.

Particle distribution: a story in two measurements

This is where it gets exciting, and unfortunately, the result isn't positive for everyone. Earlier this year, we measured the first unit and obtained a very broad particle distribution, with a main peak of 308 and 316 micrometers respectively. That was significantly higher than we expected. So we decided to take a second measurement and order another VS4 model.

The second measurement shows a solid particle distribution. At the lowest speed, the main peak is at 279 micrometers, the median (x50) at around 254. At 300 RPM, the main peak rises to 299. Thus, the VS4 is still on the broader side, but at a low speed, it's slightly further away from values that we describe sensorially as unbalanced and sometimes messy. A classic, good value that we have known from the market for a long time. Clarity-focused grinders for light specialty coffees tend to be under 240, the best at 160 to 170 micrometers. That is a different grind profile than the one the VS4 delivers.

The fine-particle content is relatively high at around 36 percent. This brings a certain dustiness, but also supports the body. In total, this is a distribution related to the VS3. Both grinders work with a conical burr set, and both show their strength with full-bodied, classic coffees. For fruity coffees that you want to brew for maximum clarity, they are the wrong choice, and we would reach for the VS6 in the Varia family.

In the cup

We tasted blindly with our reference coffee, and in the video, additionally with our Compadre, an Italian-style espresso with a focus on body. That is exactly what the VS4 delivers: a dense, creamy espresso that feels heavy in the mouth and fills the cup. A bit dusty, yes, but fitting for this type of coffee that is intended to be exactly that rich in the cup. With classic and medium roasts, the grinder feels at home. For light, very complex coffees, the result is satisfying, but not its specialty.

You can find all of our espresso grinder reviews in the Espresso Grinder Overview.