Single dosing
Shared view. Weigh each dose and put only that into the grinder. Every creator who discusses it prefers this at home. The beans stay sealed instead of sitting in a hopper, and you can swap coffees or methods between doses. It only works well on a grinder that retains little.
- Single dosing suits people who change beans or methods often and want fresh grounds, and modern single-dose grinders retain very little 11:33. A hopper grinder is still fine if you drink the same espresso every day, but its narrow range makes jumping to French press awkward 12:34. The Coffee Chronicler's suggested pairing is an electric grinder for espresso and a hand grinder for filter 13:04.
- Even when a grinder has a hopper, dose one serving at a time and never leave beans in it 5:57. On some grinders the hopper is mostly for looks, and the beans go in with the motor running 2:32.
- If you move between methods, low retention matters more than outright grind quality, because it saves purging and waste 3:01.
- Single-dose grinders went from a niche idea around 2016 to the mainstream, and the Niche Zero removed steps such as taking off a chute 5:02. Commercial hopper grinders were never designed for it and can hold up to about 5 g, though bellows and puffer mods help 8:11.
Hot start, cold start and feeding. Low-RPM and small-motor grinders can stall on dense light roasts.
- Start the motor first and add the beans slowly to avoid stalls at low rpm 8:37 5:28. A hot start lowers the risk, but it can still stall at fine settings 6:32. On the Weber EG-1, run it first and feed a few beans at a time, especially light roasts at espresso fineness 11:20.
- Feed dense light roasts slowly into an auger grinder and never tip in a full hopper at once, or the overload protection trips 9:10.
- Pick one habit and keep it. Always cold-start or always hot-start, because the motor's spin-up changes the grind 12:15. Some small grinders spit beans out of the hopper if hot-started, so feed gently instead 7:39.
- Slow feeding can move the effective grind by about one full step, and it reshapes the whole distribution as well as trimming fines 4:04. Lance Hedrick's own tests are covered in Slow feeding and RPM.
- For bouncing beans and popcorning, a lid or tamper that sits on the beans keeps them down 7:27 6:27, an anti-popcorn funnel narrows the opening 2:34, and an extension hopper stops stray bean fragments that look like retention 4:04.
| Position | By | Source |
|---|---|---|
| Prefers single dosing because beans oxidise when left in a hopper | Hedrick | 8:45 |
| For filter at home a hopper adds little, since weighing a dose is easy | Chronicler | 7:09 |
| Keep a full hopper on a café-style on-demand grinder so beans press onto the burrs and grind evenly | ECT | 1:03 |
| A full hopper exposes beans to air and light, so portion the beans or keep the hopper half full | Chronicler | 3:57 |
| Some single dosers stop by themselves once no beans are left, which frees time for other prep | Sprometheus | 4:29 |
| Prefers a single doser to switch coffees and keep weighed doses frozen. A hopper grinder wastes beans whenever you change coffee or setting | Bluebird | 1:35 3:16 |
| The café single-doses frozen 20 g portions through an EK43 to move between espresso and filter | Bluebird | 2:46 |
The European Coffee Trip row is café advice for a hopper-fed grinder with a fixed dose. The home creators are talking about single-dose grinders, so these are different set-ups more than a disagreement.
Retention
Shared view. Some grounds always stay behind. What matters is whether stale grounds end up in the next dose, which bites hardest when you switch between filter and espresso 2:01 7:04. Most creators measure a tenth or two of a gram on good single dosers and are happy with that.
- Typical figures run from about 0.1 g after bellows on a DF64P/E 3:34 and 0.1 to 0.3 g after a firm knock on the MHW-3Bomber 3:42, to 15 g in and 14.9 g out every time on the Mx. Cool Aries, with a knocker freeing the last tenth 5:52. A DF54 holds about 0.2 to 0.3 g without bellows 8:03, and the Lagom P100 about 0.1 g thanks to its high-rpm burst at the end 2:07.
- Retention rises as the grind gets finer, even after tapping 5:00 3:02, and grounds can cling in the dosing cup as well as in the grinder 3:04.
- Speed helps. Faster burrs throw grounds out of the chamber 6:02, and grinders that speed up at the end or have a knocker leave almost nothing behind 7:43 3:44.
- Declumpers can trap grounds and block bellows 11:45. Swapping a silicone declumper on a DF64 for an open plastic part cut retention and regrinding, though clumping looked no different 4:34. Removing the declumper lowers retention but raises static 11:13.
- Old grounds do swap in. An MC1 gave 17.8 g from 18 g, then 18.2 g after clearing 6:44. James Hoffmann makes the same point, that equal weight in and out doesn't prove zero retention (Retention, static and RDT).
- After swapping burrs, retention spots may need to refill before the usual low figure returns 4:17, which matches Lance Hedrick's point that retention builds to a steady state.
- To compensate, load about 0.1 g extra and tap the grinder to recover most of it 6:07.
Bellows, taps and knockers. This is where the creators differ most.
| Position | By | Source |
|---|---|---|
| Bellows help almost every grinder, and bellows plus RDT gets nearly everything out | Hedrick | 6:42 28:53 |
| Bellows are a lazy fix that blow mess around. Prefers a light tap | Hoffmann | 8:11 |
| Bellows can sharply cut retention 6:36, and the SD40 and Varia VS3 need theirs 27:34. On the Kopi Deva he'd rather cup a hand round the dose cup and tap, since bellowing sprays fines 24:03 | Rowsell | in text |
| Bellow early in the grind so coffee isn't reground 5:05. A DF83 still needs bellows even with a plasma ioniser, and he prefers a knocker design 29:10 | Rowsell | in text |
| A knock or lid pump is enough on good designs. Lifting and pressing the lid pushes air through to near zero 4:07 4:05 | Chronicler | in text |
| Bellows can reach true zero, but RDT is his preference because it also tames chute static and helps in the dosing cup 7:35. Bellows took a DF83 from about 0.2 to 0.1 g, which is fine either way 3:03 | Sprometheus | in text |
| A tilted design can behave like zero retention with no bellows or RDT 2:50. Kyle Rowsell also likes a tilted base for clearing grounds 6:35 | Sprometheus, Rowsell | in text |
| Monolith chutes need a tap, a puffer or a quick rpm rise 6:07. Flick a knocker flap twice to lower retention 3:05 | Quan | in text |
| In a café, blow out leftover grounds between brews so the next batch is clean 4:35 | ECT | in text |
| On a DF64 bellows help, but grounds still hide behind the declumper. With the bellows off a 30 g dose fits the chamber, so they load it, refit the bellows and then start the motor 3:38 4:08. The Timemore Bricks still retains noticeably despite its bellows and clearing tool 7:32 | Bluebird | in text |
Purging
Shared view. On a retaining grinder, run a little coffee through after a setting change so the first dose isn't a mix of old and new grounds. On low-retention single dosers most creators skip it, or purge only when crossing between filter and espresso.
| Position | By | Source |
|---|---|---|
| Purge 5 to 10 g after any grind change on a retaining grinder | Hoffmann | 10:38 |
| Run a few beans through when moving between filter and espresso | Hedrick | 39:33 |
| On an on-demand grinder, purge about a shot's worth before the first shot of the day | DGC | 10:41 |
| Purge 15 to 20 g after changing the setting. Once, too little purge left the shot time unchanged and gave a misleading result | ECT | 3:44 |
| Hopper grinders hold grounds in the chute, so purge between changes and after the grinder has sat idle 6:29. Commercial flats need it more than conicals 4:04 | Sprometheus | in text |
| Run the motor a few seconds after the beans have gone through 2:18. Low-retention grinders allow big setting jumps with no purge 2:32 | Sprometheus | in text |
| No purge needed on a Lagom Mini 1:04, a small one on a DF83 when switching coffee or method 4:04, and a few beans through a DF64 to clear the declumper 11:13 | Rowsell | in text |
| The Encore ESP needs a few beans through when moving from espresso to filter 6:42. On a single doser, grind a few extra beans, brush the chute and use the lid trick 4:38 | Chronicler | in text |
| EG-1 retention is low enough that he doesn't purge 12:51 | Quan | in text |
RDT and static
Shared view. A spritz or a few drops of water on the beans before grinding cuts static, mess and retention. Most creators use it on at least some grinders. They disagree about where it's needed, because it depends on the grinder and on some designs it causes problems.
- It helps most on single-dose flat grinders without an ioniser 10:11 8:09 13:15. A spritz holds retention near 0.1 g across burr sets and speeds where it otherwise varies widely 7:04, and very dry, cold air makes static worse 12:46.
- It may not be needed with an ioniser. The ionisers on the Fellow Ode Gen 2 and Opus made RDT almost unnecessary for Kyle Rowsell, though a little water still helped the Opus 3:30 7:33. Option-O still recommends it on the Lagom 01 despite the ioniser 6:41.
- On some grinders it causes problems. On the Lagom Casa damp beans stick under the anti-popcorn dome and look like retention, so a few knocks are enough 4:26. On the Lagom P64 moisture can make beans cling to the lid 4:04, and The Coffee Chronicler avoids it on the Kingrinder K6 because of reported bearing rust 31:15. Daddy Got Coffee has similar rust worries on cheap grinders (Retention, static and RDT).
- RDT beats bellows for static, because bellows mainly blow out the ultra-fine dust 2:48. Higher rpm without RDT made far more static and mess 6:35.
- As for how much, Brian Quan uses about two sprays on 18 g and shakes the beans before grinding 2:39 3:36. That's close to James Hoffmann's one spray or wet spoon, and to Lance Hedrick's advice to start at about 5 to 10 µL per gram (Retention, static and RDT).
- Flat burrs build more static than conicals, according to a discussion with Kafatek. Coffee rubs on its way out of a flat set, while a conical keeps stirring the coffee and sheds charge 7:11.
| Position | By | Source |
|---|---|---|
| The effect of RDT depends on the grinder. Start small and judge by taste | Hedrick | 39:23 |
| Uses one spray or a wet spoon routinely unless the maker advises against it | Hoffmann | 2:33 |
| Always RDT on a DF64 13:15. The Varia VS3 and Urbanic 080 are a static mess without it 25:32 | Rowsell | in text |
| Didn't use RDT in a filter test, and noticed some beans give more static 8:33. Essential when grinding with a Power Tower, and worst with dark roasts 3:16 | Chronicler | in text |
| Prefers RDT over bellows 7:35, but skips it on the Lagom Casa 4:26 | Sprometheus | in text |
| Doesn't bother on a Lagom Mini 8:10, but it's still needed on the Monolith Flat Max 12:43 | Quan | in text |
| 64 mm SSP flats generally need RDT and stricter prep, unlike a forgiving Niche Zero | Quan | 6:09 |
| A small spritz on the beans all but removed the Encore ESP's heavy static 6:41. All three Timemores in the comparison were prone to static, the hand grinder least, and the Bricks ships with a spray bottle 3:01 7:32 | Bluebird | in text |
Distribution and WDT
Shared view. For espresso, an even bed (flat on top and even in density underneath) matters more than tamp force, and a fine-needle WDT tool is the most reliable way to get there. Levelling or spinning tools that only work the surface do less. This matches James Hoffmann's and Lance Hedrick's advice in Dialling in espresso.
- Sprometheus tested the tools on one coffee, grinder and machine. Hand tapping gave a spread of up to about 2% extraction and at least one channel per shot 3:02. A levelling tool (OCD) was more consistent but on the low side, and seven of ten bottomless shots channelled 4:04. WDT gave 20%+ extractions with only two of ten channelling 4:35, and a blind shaker cup followed by WDT was best overall 6:35. In a 2025 test a vibration distributor alone did well (19.4 to 21.3%) and a classic WDT tool gave 19.2% with a sweeter, fuller shot, but stacking vibration with WDT did worse than either 7:43 5:32 6:04.
- Spinning blades smooth the top but can leave uneven density below, which shows up as channelling 2:14. A levelling tool also acts as a light or heavy tamp depending on its depth 2:13.
- Brian Quan rakes the very bottom of the basket in circles, then repeats while working upwards. He finishes with a vertical slam, and if the funnel leaves a ring, he rakes the surface lightly and slams again 2:02 3:05. Needles of about 0.4 mm or thinner work best, and scratching the basket doesn't matter because the channels from poor prep are what you taste 12:21.
- Flat-burr grounds are fluffier and easier to stir than compacted conical grounds 9:10. Moving grounds over from a dosing cup creates clumps, which makes WDT more important 5:09.
- Distribution starts while grinding. Aim for the grounds to fall evenly so the bed has no hills before you tamp 0:22. Sweeping with a finger only moves the top layer 0:53.
- Automatic WDT (an AutoComb) made café prep identical shot to shot, so any drift could be traced to the grind. At home, manual WDT is probably the better buy 0:32 4:48.
- Filter brews have their own version. Shake the bed flat before pouring 4:41, stir an AeroPress back and forth instead of in a vortex so the bed stays flat 5:01, and needle the dry bed before brewing so water reaches it all at once 2:52 3:06. Brian Quan uses a leaf-shaped tool to stir the bloom in a cone ("wet WDT") without tearing the paper 8:16 3:36.
- Bluebird covered distribution in an Under Extracted episode. Tapping the portafilter levels the surface but hides gaps lower down and depends on the barista 2:32. WDT breaks up clumps through the whole depth, a funnel keeps it tidy, and it matters most on cheaper grinders that clump 3:35. On the bar they use a Nucleus Coffee Distributor, which reaches into the bed as well as levelling it 4:38. For espresso they rake in rings from the bottom upwards before one light tap and the tamp 10:02, and light roasts on a Mahlkönig X54 need WDT to avoid channelling 3:47.
| Position | By | Source |
|---|---|---|
| Use a fine-needle WDT tool. Wedge tools only level the top | Hoffmann | 5:04 |
| Tap the portafilter and use a fine-needle WDT tool | Hedrick | 8:08 |
| Uses WDT even when a grinder has a built-in stirrer, to break up clumps 11:17 | Rowsell | in text |
| WDT can replace a clump crusher when grinding fine 10:45 | Chronicler | in text |
| Still uses WDT with fluffy grounds for the cleanest bottomless shots 4:21. Less prep was better when combining tools 6:04 | Sprometheus | in text |
| Has dropped levellers and spinning distributors, and dislikes hooked WDT tools that shovel the grounds into clumps 0:00. Big conicals can often skip WDT (shake and tamp), and flats usually need more 4:39 | Quan | in text |
| Don't bang the portafilter to settle the bed, because it can crack the puck | ECT | 2:35 |
| Uses vertical slams to collapse a tall bed before tamping | Quan | 6:09 |
| WDT or a distributor that works through the bed. Tapping hides gaps lower down | Bluebird | 2:32 4:38 |
The European Coffee Trip and Brian Quan slam rows really do disagree. Gwilym Davies (on European Coffee Trip, 2015) warns against knocking the portafilter hard, while Brian Quan (2022) slams it vertically on purpose after WDT.
Puck prep and tamping
Shared view. Tamp once, level, and firmly enough to remove the air. More force doesn't help. Lance Hedrick calls harder tamping to slow a shot a myth, James Hoffmann says tamp pressure is binary, and the newer creators agree.
- Tamping removes air pockets and leaves a flat surface. Extra force strains the wrist and risks an uneven tamp 0:22. One tamp is enough, and the polishing twist probably adds little 1:55. Lift the tamper out gently so suction doesn't pull the puck 1:23, and lock the portafilter in gently 2:05. If you lean to one side, check how level you are every few shots 2:29.
- Don't skip it. Untamped shots channelled and tasted thin and sour at every grind and dose tried, even with WDT, and grinding finer didn't rescue them 1:09 1:42. A tamped puck has headspace below the shower screen, while an overfilled or untamped basket touches it and invites bypass 3:26.
- Change the grind before the tamp pressure 1:42. The exception is a grinder with only one usable espresso step, where dose and tamp are the only things left to change 7:24.
- On lever and manual machines, tamp lightly, just to resistance 3:42, and on a soft surface so the basket isn't stressed 3:07.
- A puck screen under the shower screen slowed a shot so much that the grind had to go much coarser, but it gave tidier pucks and steadier flow late in the shot 1:01 3:02 6:08. Puck screens also clean up turbo shots 4:20.
- Precision baskets removed bitterness and thinness compared with the stock basket, though the extraction gain was modest 4:35 2:37.
- Check the spent puck for clumps, a level tamp and channels. A channelled side looked darker and weaker 3:12. A bottomless portafilter shows channelling as sprays 1:26.
- Funnels that sit on the portafilter rim avoid the mound that drop-in funnels leave 10:27.
- The grinder changes how much prep you need. Big conicals are forgiving 11:10, while analytical flat burrs punish sloppy prep 4:09 10:36. A profiling machine can partly cover for uneven prep 10:14.
- Bluebird has three tamping rules. Use a tamper that fits the basket, keep it level throughout, and press until the bed pushes back. You judge the pressure by that resistance instead of a number of kilos 6:09 6:41. Hold it like a doorknob between thumb and index finger with the arm near 90°, and if it ends up crooked, leave it instead of tamping again 7:12. The tamp adds resistance so water spreads through the puck instead of racing through loose grounds 5:38.
- Match the dose to the basket. An overfilled small basket (a Breville Barista Express, for example) channels and gives thin, muddy shots, so dose within its range 4:36. The café allows about 0.3 g either side of the target dose and weighs every shot 2:34.
| Position | By | Source |
|---|---|---|
| Tamp level until it stops moving. Harder does nothing | Hedrick | 12:44 |
| Tamp pressure is binary | Hoffmann | 16:13 |
| A brief tamp after distribution, where consistent movement is the skill (with Boram Um) | Rowsell | 3:02 |
| Change the grind first. Tamping isn't a way to dial in, but don't skip it | Sprometheus | 1:42 |
| Tamp lightly and level. Heavy force only risks injury (Gwilym Davies) | ECT | 0:22 |
| Only WDT and a tamp, with no spinning tools | Quan | 0:31 |
| On a single-setting grinder, tune espresso with dose and tamp pressure | Chronicler | 7:24 |
| Tamp level until the bed resists, judged by feel instead of a force figure, and don't re-tamp a crooked puck | Bluebird | 6:41 7:12 |
Bean storage and freshness
There isn't much on this. The six newer creators add these points, and none of them conflicts with the other pages.
- Keeping beans in the roaster's bag is fine for a while. Espresso wants fresher beans than filter, and properly frozen coffee keeps for a year or more 18:35.
- Six-month-old beans in a badly sealed bag spoil espresso on any machine 10:31, and beans left in a hopper see air and light 3:57.
- In a café, resting light-roast espresso coffee for at least four weeks removed most of the variation in shot time 1:03.
- Coffee several weeks past roast holds less CO₂, so the bloom matters less, while very fresh coffee needs it 6:40. With freshly roasted coffee, Brian Quan grinds ahead and lets it degas, then uses a longer bloom 3:08.
- Bluebird sells some rare lots in pre-portioned tubes of about 20 g for home freezing 8:32, and brews rare coffees at 12 g so a 100 g bag gives about eight cups 3:46.
Other workflow tips
- Cleaning. Never clean burrs with water (rust) or oats (they lodge in the burrs). Open the burrs to the coarsest setting and use an air blower 15:18 16:18. With light roasts, every couple of months is enough 13:48. Cafés vacuum daily and deep-clean weekly 6:43. Clean a Comandante weekly if it's heavily used and monthly otherwise, never undo the bottom screws, and find zero again afterwards 6:44. Keep a plasma ioniser clean so it doesn't add retention 13:18.
- Hand grinding. Hold a Comandante upright and turn at a steady pace, because spinning fast doesn't help 11:49. Fines and chaff that cling to the bottom of the jar can be thrown away instead of tapped back in 12:21. Hand grinding for espresso makes dialling in tiring, because every binned shot means grinding again 5:43.
- Seasoning. New espresso burrs improved after 3 to 5 kg 6:36. European Coffee Trip suggests at least 3 kg on a fine setting in a café 6:12, and a Kafatek engineer said a couple of pounds is enough for coated burrs 13:20. The other creators' views are in Seasoning.
- Describe settings from zero. Each unit's zero is different, so quote turns or clicks past zero instead of dial numbers 8:24, and write the click positions down when switching between espresso and filter 3:40.
- Sifting fines. Sifting gives cleaner, crisper cups but lowers extraction and complexity, so Sprometheus keeps it for delicate coffees 1:33. The Coffee Chronicler uses a cheap sieve to fix slow drains 7:13, and you may need to grind finer afterwards 23:04.
- Preheating and rinsing. Rinse papers and preheat brewers to keep the temperature steady 5:34. On a Switch, rinse with the valve open, then close it and pour the rinse away 1:30. Flush some water through the kettle spout first, as the spout runs at a different temperature from the display 3:06. For a Flair, preheat the head and portafilter with several pours of boiling water 2:07.
- Kettle off. Several of Brian Quan's recipes switch the kettle off and let the water cool through the brew for a sweeter, rounder cup 9:13 9:41.
- Weigh, don't scoop. Bean density varies with roast and origin, so use a scale 4:03. If you have no precise tools, dosing by volume and matching the cup level still gives decent espresso 9:31.
- Grinder first. Kyle Rowsell would buy and learn the grinder before upgrading the machine or accessories 2:32, and would fix the water before replacing a Baratza Encore 21:10.
- Water (Bluebird). Aim for roughly 70 to 120 ppm, which a cheap TDS meter can confirm. Their café water sits around 80 to 100 ppm, with about twice as much calcium as magnesium 5:09 4:07. For espresso, filter out chlorine and remineralise instead of using bare RO water 8:01.
- Mix the brew. The first drips are much stronger than the last, so stir the cup or swirl the carafe before drinking 6:08 6:15 8:09.
- Batch brewers. Heat the machine with a water-only cycle and brew at full capacity 5:36 4:35.
- Refractometers. A DiFluid R2 reads differently from an ATAGO but consistently, so it works for comparing your own brews. The VST is the industry reference and the most expensive 5:38.
- Quick iced coffee. Chill a hot brew fast in a container in the freezer without letting it freeze, then pour it over ice 10:17.
Sources
Every claim links to the moment it comes from. Video titles and dates for the five newer channels are in data/sources.json.
Summarised in our own words from the creators' videos, with every point linked to the moment it comes from. Notchbook isn't affiliated with or endorsed by any of these creators, so please watch the originals for full context. Sources
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