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 extracting excellent flavors without pronounced bitterness, even when I was grinding finely and pulling very long shots of espresso. Particle size analysis with the Difluid Omni showed that on the fine espresso settings, the Philos was significantly more precise than grinders in the $200-$500 range, with fewer fines and virtually no large rocks, as one would of course expect. This gave me a blessed margin of error, with less chance of nasty notes.

Espresso enthusiasts have long believed that grinders are as important, if not more so, than the machine you use to brew the coffee, and so I put that to the test. I’ve used ground coffee with the Philos to pull shots on machines ranging from a high-end double boiler from Breville to a semi-automatic from Ninja and an entry-level De’Longhi. Not only did I get syrup-rich results on the Ninja that I’ve never seen before on this machine, but at least one of the Ninja shots I shot was among my favorites from recent months.

Clean slate, clean coffee

Perhaps the biggest selling point of the Philos is its zero retention claim. Zero retention is of course the unattainable 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 the ones that flow into your grinding cup.

In practice, this is generally not what happens. The burrs on your coffee grinder are full of little ridges that like to trap coffee grounds before they reach their intended destination. The interior of a crusher may contain several gullies and dead ends. Static electricity means the coffee fines can attach anywhere along the route. Depending on your grinder, the beans that end up in your grinding cup may contain half a gram or more of stale coffee grounds from the last time you ground coffee beans.

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

Philos advertises “retention-free” grinding, and the device does a lot to achieve this. The burrs are oriented vertically, which helps. So make a short chute, vibration dampers and a metal plate that serves to ground the device against static electricity. The device has a small spring-loaded hammer to remove stray burrs in the grinding cup. It also comes with a “dose finisher” that you can insert into the grind chute to be really sure you get all the coffee grounds.

All of these anti-retention measures still don’t add up to zero, but the Philos comes remarkably close. To test this, I opened the device and brushed or shook off any leftover coffee, then weighed the result. On filter coffee, even without a 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.