What I didn’t expect was how forgiving this grinder was on light-to-medium beans, in terms of coaxing excellent flavors without extreme bitterness, even when I grinded well and pulled very long espresso shots. Particle size analysis using the Difluid Omni shows that in good espresso settings, the Philos is more accurate than the grinders in the $200 to $500 range, with less fines and almost no stones-as one, of course, has every right to expect. This gives me plenty of room for error, with less risk of harsh notes.

Espresso nerds have long seen that grinders are as important or more important than the machine you use to brew coffee, and so I gave it a try. I use a Philos coffee grinder to take shots of machines from a top-line Breville dual-boiler to a semiautomatic from Ninja and an entry-level De’Longhi. Not only did I achieve syrupy-rich Ninja results that I had never seen before with the machine, even one of the Ninja shots I got was one of my favorites in recent months.

Clean Slate, Clean Coffee

Perhaps the biggest selling point of Philos is its zero retention claim. Zero maintenance is, of course, the unattainable dream of a coffee grinder. The idea is that if you put 18 grams of coffee beans in your grinder, the same 18 grams of coffee should flow into your grind cup.

In practice, this is not usually the case. The burrs in your coffee grinder are full of little ridges that want to trap the coffee grounds before they reach their intended destination. The interior of a grinder can have many gullies and dead ends. Static electricity means that the coffee fines can embed themselves anywhere along the route. Depending on your grinder, the beans that end up in your grind cup may include half a gram or more of stale coffee grounds from the last time you ground coffee beans.

You don’t want it. 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 like it.

Philos advertises “zero retention” grinding, and the device does a lot to make it happen. The burrs are oriented vertically, which helps. So is a short chute, vibration dampener, and a metal plate that serves to ground the device against static electricity. The device has a small spring-loaded thumper to remove any stray burrs into the grind cup. It also comes with a “dose finisher” that you can insert into the grind chute to make sure, you’ve got all the coffee grounds.

All of these measures against sustainability still don’t add up to zero, but Philos comes very close. To test this, I open the device and brush or shake off all the coffee residue, then weigh the result. In filter coffee, even without the dose finisher, the amount of coffee grounds trapped in the grinder is less than a tenth of a gram—an amount too small to register on my scale.