RDT Spray Bottle

Reduce static and keep your coffee-grinding workflow cleaner.

This compact RDT spray bottle is designed for the Ross Droplet Technique (RDT): applying a very fine mist of water to a measured dose of coffee beans immediately before grinding. A small amount of moisture can help reduce static, clumping and scattered grounds, particularly in dry conditions.

For more practical advice, see our guide to reducing static when grinding coffee.

Why use RDT?

• Less static and mess: helps reduce grounds clinging to your grinder chute, dosing cup and surrounding bench.
• Cleaner dose transfer: helps more of your ground coffee reach the dosing cup or portafilter.
• A more predictable workflow: particularly useful when single dosing or grinding coffee in dry conditions.

How to use the RDT spray bottle

1. Weigh your coffee beans and place them in a dosing cup or small container.
2. Start with one fine mist. Use only enough water to lightly moisten the beans.
3. Swirl or shake briefly to distribute the moisture, then grind immediately.

Important: Never spray water directly into the grinder. The beans should be very lightly moistened, not wet, and no water should pool in the dosing cup or grinder.

Use fresh, clean or filtered water, keep the bottle capped between uses, and rinse it periodically.

For an even cleaner single-dose setup, pair it with our metal dosing cup for the DF54 and DF64 Gen 2.