Single Dose Coffee Grinder: What It Is and Who It's For

A single dose coffee grinder is built to grind one weighed dose of beans at a time: you weigh out, say, 18 grams, pour them in, grind all of them, and nothing stays behind in a hopper. What makes a grinder good at it is low retention, meaning very little ground coffee stays inside to end up in your next cup.

This post explains how single dosing works, why retention is the spec that matters, which design features help, who should buy one and who shouldn't, and which models to look at.

What single dosing means

Most traditional grinders have a hopper on top that holds a bag's worth of beans. You fill it, and every time you grind, beans feed from the hopper into the burrs. The beans live in the grinder.

Single dosing flips that. Your beans stay sealed in their bag or container. Before each brew you weigh a dose on a scale, drop it into the grinder, and grind until the burrs run empty. The grinder holds nothing between uses.

Eureka's marketing team told Barista Magazine that people single dose mainly for "preserving freshness and more precise measurements." Both follow from the workflow: beans aren't sitting in an open hopper, and the weight you put in is close to the weight you get out.

There's a third reason home brewers like it: switching coffees. If you have a light roast for pour-over and a darker blend for espresso, a single-dose grinder lets you grind either one on demand without emptying a hopper. See the single dosing glossary entry for the short version.

Retention, and why it matters

Retention is the ground coffee that stays inside a grinder after it stops: in the burr chamber, the chute and the exit spout. Every burr grinder retains some. The question is how much, and whether it gets swapped into your next dose.

Retention causes two problems.

Stale coffee in your fresh dose. Niche Coffee told Barista Magazine that retained grounds go stale "a lot like bread," and gave the example of half a gram of an 18 gram dose staying in the grinder and coming out in the next coffee.

Wrong-sized grounds. A DF64 representative in the same article pointed out that if you move from a coarse setting to a fine one, any retained grounds "will be the wrong grind size for your next brew." Baratza says the same in its own guide to changing settings: after a big change, the leftover grounds still reflect the old setting, and it recommends "a quick purge, just a second or two of grinding" to flush them.

On a hopper grinder used for one coffee all day, a little retention barely matters, because it's the same coffee ground minutes ago. When you grind one dose at a time, it matters a lot. Niche put it plainly: "If you are grinding one grind at a time, you want as little retention as possible so your grind is fresh and what you put in is what you get out."

How much is "low"?

Independent measurement is more useful than marketing. The German retailer and reviewer Kaffeemacher separates retention into two kinds: permanent (coffee stuck in the grinder that never moves) and temporary (coffee that swaps out with each grind). Only the temporary part ends up in your cup.

When Kaffeemacher remeasured the Niche Zero in October 2025, it found 0.2 grams of temporary retention and 0.7 grams of permanent retention. The same review says that with many grinders retention runs to several grams, and that it measured 4 to 5 grams on a Graef CM800.

Note that even a grinder named "Zero" isn't zero. Turin says the same of its DF64 Gen 2.7: low retention "does not mean every dose will have identical input and output weight." For more on causes and fixes, read the grind retention glossary entry.

What makes a grinder suited to single dosing

No single feature makes a grinder "single dose." It's a set of design choices that leave less room for coffee to hide and make it easy to clear out what's left.

A short, direct grind path. Niche told Barista Magazine its approach is a "lack of empty space in the grinder for grounds to get caught in and a straight-through grind path." Eureka's Mignon Single Dose tilts its body 15 degrees, which the maker calls "inclined" to zero retention.

Bellows. A rubber bellows sits on top of the bean inlet. You squeeze it after grinding, and the air pushes leftover grounds out of the chamber. Turin fits bellows to the DF64 Gen 2.7 for this reason. Niche noted in Barista Magazine that bellows do help, but also push grounds "where it doesn't usually get," so they are not a substitute for cleaning.

Static control. Charged grounds cling to the chute and cup. Makers use anti-static materials, ion generators and knockers. Fellow pairs "anti-static technology and a built-in knocker" on the Ode Gen 2. Turin uses a plasma ion generator on the DF64 Gen 2.7 and says its effect varies with humidity, beans and cleanliness. Spraying beans with a drop of water before grinding, called RDT, helps on any grinder.

No hopper, or a small one. Single-dose grinders swap the big hopper for a small funnel, a bellows cup or a lidded chamber. Turin lists about 50 grams of capacity with the bellows on the DF64 Gen 2.7, and Eureka lists 45 grams for the Mignon Single Dose. That's enough for one or two doses, not a bag.

Stepless adjustment helps. Many single-dose grinders are stepless, which makes it easier to move between espresso and filter without being stuck between clicks. It isn't required, but it fits the "different coffee, different setting" workflow.

Who a single-dose grinder is for

• People who switch coffees often. If you keep two or three bags open, single dosing means each brew uses only the coffee you meant to use.
• People who switch methods. Espresso in the morning and pour-over in the afternoon means big setting changes. A low-retention grinder gives you fewer wrong-sized grounds after each change.
• Espresso drinkers who weigh doses. If you already weigh in and weigh out, a grinder that returns close to what you put in keeps your ratio honest.
• People who brew once or twice a day. Grounds left in a grinder overnight are the stale grounds Niche warned about. Single dosing avoids that.

Who it isn't for

• People who want a button. Turin itself says the DF64 Gen 2.7 is "a hands-on single-dose workflow," and points buyers who would rather leave beans in a hopper and press a programmed dose button to a different model. Weighing every dose is an extra step every morning.
• Households grinding many cups in a row for one coffee. If the same beans go through the grinder all day, a hopper grinder's small retention is mostly the coffee you just ground.
• People who won't own a scale. Single dosing only works if you weigh the beans. If that sounds like a chore, a hopper grinder will be easier to live with.
• Filter-only drinkers looking at espresso-capable models. Some single-dose grinders are brew-only. Fellow states the Ode Gen 2 "is not suitable for espresso." That's fine if you never pull shots, but check before buying if you might.

Grinders to look at

These are single-dose grinders with BrewMark buying guides. They're listed in no particular order, and each guide collects the maker's specs and published reviews.

• Niche Zero: 63 mm conical burrs and a stepless dial. Kaffeemacher measured 0.2 grams of temporary retention in its 2025 remeasurement.
• Turin DF64 Gen 2: 64 mm flat burrs, stepless adjustment, bellows and a plasma ion generator, according to Turin's product page.
• Eureka Mignon Single Dose: a 15 degree inclined body, what Eureka calls a "Blow Up System" for clearing retention, and its ACE anti-clump and anti-static system.
• Fellow Ode Gen 2: 64 mm flat burrs, single-dose loading with a 100 gram grind capacity, and anti-static technology with a knocker. Brewed coffee only, per Fellow.
• Varia VS3 (2nd Gen): a compact conical burr grinder that Varia describes as built for single-dose grinding with stepless control. Its grind chart runs from espresso to cold brew.

To weigh two of them side by side, start with these comparisons:

• Turin DF64 Gen 2 vs Niche Zero: flat burrs against conical, both stepless.
• Turin DF64 Gen 2 vs Eureka Mignon Single Dose: two espresso-capable single-dose designs.
• Turin DF64 Gen 2 vs Varia VS3: a full-size flat burr grinder against a compact conical one.

Or let the finder narrow it down for you. This link opens it with espresso and pour-over selected and single dosing set as a must-have: find a single-dose grinder.

Already own one?

Every grinder above has a settings chart with starting points for each brew method, taken from the maker's own chart where one exists. Find yours on the grinder settings hub, or compare methods on the master grind size chart. If you're dialing in shots, the espresso grind size guide covers shot time and taste.

Next steps

• Look up your grinder's starting settings on the grinder settings hub or the master grind size chart.
• Brew a pour-over with the new grinder using James Hoffmann's V60 recipe, or browse all brew guides.
• Set up a new single-dose grinder with how to dial in a new grinder.
• Moving from a hopper grinder? Convert your grind settings between grinders so you don't start from scratch.