How to lubricate a coffee grinder?

Lubricating a coffee grinder concerns the internal mechanical components — bearings, gears, burr shaft — and never the burrs themselves, which must remain perfectly dry. It is recommended at first assembly of a new grinder or after burr replacement, and periodically per manufacturer guidelines (typically every 200–500 kg of coffee ground). The lubricant must be food-safe certified (FDA or equivalent), PTFE or silicone based, with no fragrance or solvents.

Most domestic coffee grinders do not require regular lubrication during their normal lifespan — their bearings are factory pre-lubricated and sealed. But for semi-professional grinders under intensive use, certain manual grinders with open gear trains, and grinders whose bearings are user-accessible, lubrication is part of preventive maintenance.

The first point to understand is the distinction between parts that should be lubricated and those that must never be greased. Burrs (whether conical or flat, in steel, ceramic or carbide) must never be lubricated — any trace of grease would contaminate the grind and the cup. The mechanical parts that transmit movement may benefit from lubrication: main burr shaft, bearings, reduction gears, adjustment mechanisms.

The recommended product is an H1-certified food-grade grease (direct food contact authorised under NSF/ANSI 51). PTFE (polytetrafluoroethylene) based greases are excellent for parts subject to high temperature or heavy load. Silicone greases work well for seals and plastic parts. Standard mineral greases are not recommended in a food context.

The procedure varies by model. On a manual grinder such as a Comandante or 1Zpresso, the manufacturer sometimes advises lubricating the rotation shaft with a micro-drop of food-grade oil after several hundred uses. On professional electric grinders with open conical burrs, burr replacement is often accompanied by cleaning and light lubrication of shaft bearings with a dosing syringe. In all cases, the amount of grease should be minimal — a cotton swab tip is usually enough for small parts.

A practical sign that lubrication may be needed: a grinder producing unusual squeaking or cracking during burr rotation, or increased resistance during grinding. These symptoms can also indicate bearing wear — in which case lubrication alone will not be enough and part replacement will be necessary.

Grinder lubrication: what, where and when