Mazzer Philos Review (2026): Sweet, Zero-Retention Grinds

What I didn’t expect was how forgiving this grinder would be with light-to-medium beans, in terms of coaxing out excellent flavors without harsh bitterness, even when I ground finely and pulled very long espresso shots. Particle size analysis with the Difluid Omni showed that on fine espresso settings, the Philos was significantly more precise than grinders in the $200 to $500 range, with fewer fines and pretty much no coarse boulders—as one would, of course, have every right to expect. This gave me blessed room for error, with less risk of harsh off notes.

It’s long been a saw of espresso nerds that grinders matter as much or more than the machine you use to brew the coffee, and so I tested this. I used coffee ground with the Philos to pull shots on machines ranging from Breville’s top-line dual-boiler to a semiautomatic from Ninja and an entry-level De’Longhi. Not only did I achieve syrupy-rich results on the Ninja I’d never seen before on that machine, at least one of the Ninja shots I pulled was among my favorites of recent months.

Clean Slate, Clean Coffee

Perhaps the biggest single selling point of the Philos is its claim to zero retention. Zero retention is, of course, the unreachable dream of a coffee grinder. The idea is that if you put 18 grams of coffee beans into your grinder, the same 18 grams of coffee should be what spills into your grind cup.

In practice, this isn’t usually what happens. The burrs in your coffee grinder are full of little ridges that like to trap coffee grounds before they reach their intended destination. A grinder’s interior might contain multiple gullies and dead ends. Static electricity means that coffee fines can affix themselves anywhere along the route. Depending on your grinder, the beans that end up in your grind cup might include a half-gram or more of stale coffee grounds from the last time you ground coffee beans.

You don’t want this. But to avoid brewing coffee grounds from yesterday’s batch, the usual solution is to grind extra beans and then throw them away. You probably don’t want this, either.

Philos advertises “zero retention” grinding, and the device does a lot to accomplish this. The burrs are oriented vertically, which helps. So do a short chute, vibration dampeners, and a metallic plate that serves to ground the device against static electricity. The device has a little spring-loaded thumper to knock loose any stray burrs into the grind cup. It also comes with a “dose finisher” you can insert into the grind chute to make really, really sure you got all the coffee grounds.

All of these anti-retention measures still didn’t add up to zero, but the Philos gets remarkably close. To test this, I opened the device and brushed or shook out all the leftover coffee, then weighed the result. On filter coffee, even without the dose finisher, the amount of coffee grounds trapped in the grinder was less than a tenth of a gram—an amount too small to register on my scale.