What is single dosing in a coffee grinder?

The workflow:

1. Weigh out one shot's worth of beans on a scale (18.0 grams for a standard double espresso).
2. Drop the beans into the grinder hopper or chute (some grinders have a small "single dose" cup that replaces the hopper; others just take loose beans through the bean cap).
3. Grind. The beans pass through the burrs and exit into the dosing cup or portafilter.
4. Tap the grinder a few times to dislodge any retained grounds. On low-retention grinders, this can be skipped.
5. Brew with that dose. The next session starts the same way.

Compare with hopper-fed: dump 250g of beans into the hopper, grind a "dose by time" or "dose by weight" amount, walk away. The hopper holds beans for the next 12+ shots, but those beans sit exposed to air and lose freshness.

• Bean switching — you can use a different coffee every shot without purging 30g of the old bean through the grinder first. Useful for cuppers, multi-bean households, and tasting flights.
• Freshness — beans in a hopper start staling within 24-48 hours of contact with air. A single-dose workflow keeps the unground beans in a sealed bag or vacuum canister until the moment of grinding.
• Dose accuracy — weighing each shot means your dose is exact every time, which improves shot consistency for users sensitive to ±0.5g variations.
• Cleaner countertop — no permanent bean hopper means a more minimal grinder footprint, which matters in small kitchens.

Single dosing is not free. The real trade-offs:

• Time per shot. Weighing in, weighing out, tapping for retention — single dosing adds 30-60 seconds vs a hopper-fed grinder. For one shot a day this is invisible; for a household making 4 shots back-to-back, it adds up.
• Grinder selection matters more. Most hopper-fed grinders have 3-10g of retention by design — the beans in the hopper push the previous session's grounds through. Single dosing exposes that retention because you do not have hopper weight to mask it. Grinders explicitly designed for single dose (DF64, Niche Zero, Lagom P64) have under-1g retention.
• Scale dependency. You need a precise scale (0.1g resolution) and the habit of using it every shot. Weighing fatigue is real.
• Bean static and clumping. Single-dose grinders often need RDT (Ross Droplet Technique — a spritz of water on the beans before grinding) to reduce static. Hopper-fed grinders are less affected because the bean mass dampens static buildup.
• Workflow rigidity. "Grab and pull" — drop a few beans in, no scale, go — is harder. Single dosing rewards discipline more than spontaneity.

Single dosing makes sense when (a) you regularly use more than one bean and want to switch without purging, (b) you are dialing light roasts or specialty single origins where small dose variation matters, (c) you value freshness over speed, or (d) you genuinely enjoy the weighing-and-grinding ritual. It is a deliberate workflow choice, not a universal best practice.

It does not make sense when you (a) drink one bean continuously for months at a time (a hopper just stores it), (b) need fast service for multiple drinks back-to-back, or (c) treat espresso as a quick utility rather than a hobby. A Eureka Mignon Specialita with hopper does great shots and takes 8 seconds; a Niche Zero with single dose takes 40 seconds and the cup is the same if you use the same beans.

The category exploded between 2018 and 2024. The most-discussed options:

• Niche Zero — 63mm conical burrs, near-zero retention, sold direct from UK. The reference single-dose home electric.
• DF64 / DF64 Gen 2 — 64mm flat burrs, single-dose by design, much cheaper than Niche ($400-700 vs $700-900). Multiple OEM variants.
• Fellow Ode Gen 2 — 64mm flat burrs, single-dose, filter-focused (not designed for espresso). Sleek aesthetic for kitchen counters.
• Lagom P64 / P100 — premium tier, 64mm and 98mm flats, $1,200-2,500 for users who want top-end.

You can also single-dose a hopper grinder by simply not filling the hopper — drop 18g in, grind, repeat. This works on some grinders better than others. Generally a grinder needs low retention and a workable bean drop path to make it usable; many traditional doser grinders fight you.