GRINDER TALK · HOSTAGE SITUATION
Somewhere inside your grinder is coffee from Tuesday. It would like to be included in Thursday’s shot.
That’s retention. Ground coffee that goes into the grinder and doesn’t come out with the rest. It sits in the burr chamber, the chute, the corners. Then one day it leaves, mixed into a dose that was supposed to be fresh.
First, the fact that beats the joke
The “gram” in our headline is a figure of speech. The grinder makers we cover don’t publish a retention figure in grams for the Encore ESP, the Sette 270, or the original Opus, and we don’t have a lab. Owner-reported numbers float around forums, but we haven’t seen them measured in a way we’d repeat. So: no number here. Just how it works and what to do about it.
Why it matters
CoffeeReview explains it well. Grounds stuck inside a grinder can come loose later and get swept out with fresher grounds, “imparting off-flavors and changing the character of your cup.” They can also lead to maintenance problems over time. Static makes it worse, because charged grounds cling to surfaces inside and out.
Espresso doses are small. The Bambino Plus double basket is built for 16 to 19 g. Any old coffee that tags along is a bigger share of a small dose than it would be in a big batch of drip. And if you single dose, retention is the reason beans-in doesn’t always equal grounds-out.
Retention isn’t a defect. It’s physics with a cleaning schedule.
What the grinder makers do about it
| Encore ESP | Sette 270 | Opus 2 | |
|---|---|---|---|
| Burrs | 40mm conical steel (M2) | 40mm conical (S1) | 48mm conical |
| Design note | Quick-release burr for cleaning | No-chute design, grinds straight into portafilter or bin | Internal impeller; anti-static ionizer |
| Maker’s retention wording | None published | “Less waste” | “Near-zero grind retention” |
Baratza says the Sette 270‘s no-chute design sends coffee “directly from the grind chamber into your portafilter or grounds bin.” Fewer places for grounds to hide. Fellow says the Opus 2’s impeller moves grounds through “without old grounds carrying over,” and lists “near-zero grind retention” as a headline feature. For the original Opus, Fellow’s FAQ says the anti-static works best for about 60 grinding cycles before the exit chute needs a quick brush.
The Encore ESP doesn’t make a retention claim on Baratza’s page. It does make cleaning easy: the cone burr lifts out without tools.
What you can do about it
- Purge after changing the grind. Baratza’s Sette manual says to run 1 to 2 seconds more and toss it. That’s “crucial in making sure all the ground coffee used is from the same setting.”
- Brush the burrs. The Encore ESP manual says about once a month if you grind daily. The Sette manual says every few months, with a stiff brush or cleaning tablets.
- Never wash the burrs. Both Baratza manuals say water will rust them.
- Go easy on oily and flavored beans. Baratza says built-up oils can make grounds stick and clog the grinder.
- Weigh in, weigh out. A scale tells you how your grinder actually behaves. Retention is easier to manage once you can see it.
Retention vs. static vs. a clog
Different problems, same mess. Static is grounds jumping onto the counter and clinging to the catch cup. Retention is grounds staying inside. A clog is retention that got ambitious, usually from oily coffee or an overfilled bin backing up into the chute. Both Baratza manuals warn about that last one. Empty the bin before it hits the max line.
One more habit: when you switch beans, run a little of the new coffee through and toss it. Whatever was left behind from the old bag goes with it. It costs a couple of grams. It buys you a shot that tastes like the coffee you just paid for.
None of this means you need a new grinder. It means you need a brush, a habit, and maybe a couple of seconds of purge. Our maintenance hub covers burr cleaning and swaps in more detail.
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Basis: manufacturer specs and manuals, the references linked below, and price. We have not run this gear through our own testing, and we won’t pretend otherwise.
Sources
- CoffeeReview: Mid-range burr grinder equipment report (2020)
- Breville: Bambino Plus instruction booklet (PDF)
- Baratza: Encore ESP product page
- Baratza: Encore ESP operations manual (PDF)
- Baratza: Sette 270 product page
- Baratza: Sette 270 manual (PDF)
- Fellow: Opus 2 product page
- Fellow: Opus gear guide and FAQ
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