Guide · Buying and safety
Espresso accessories you don't need
Which popular espresso accessories have weak or no published evidence behind them, which are worth keeping for other reasons, and where to spend first.
We may earn a commission if you buy through links on this page, at no extra cost to you. Unless a page says otherwise, our picks come from published specifications and listing research, not hands-on testing. How we make money · How we research
Short answer
Skip, or at least postpone: a spinning distributor if you already use WDT, a tamper bought for its force number, an RDT sprayer bought for better extraction, and a puck screen bought for taste. Published tests found no extraction benefit from the first three, and we found no controlled evidence for the fourth.[1][2][3] Spend first on a scale, a tamper that fits your basket and a needle tool.
The short list
| Accessory | Why you can skip it | Keep it if |
|---|---|---|
| Spinning distributor after WDT | In a controlled test, OCD-style distributors lowered strength and extraction compared with none[1] | You like the flat surface and your shots taste right |
| A tamper chosen for its "30 lb" | Tamp force from 5 to 20 kg made no difference to strength (TDS)[2] | You want the same tamp every time; any spring weight will do |
| RDT sprayer for extraction | No significant TDS change, and shot times may have become less consistent[3] | Static makes a mess of your grinder or counter |
| Puck screen for taste | We found no controlled study showing a taste or extraction gain | You want a cleaner shower screen |
| A 58.5 mm "upgrade" tamper | The basket makers we checked, VST and IMS, specify 58.4 mm, and Decent advises against 58.5 mm[4][5][6] | Your basket maker accepts 58.5 mm |
| Bottomless portafilter for flavor | We found no evidence it improves flavor by itself | You want to see how your shots flow |
| A basket chosen for its hole count | Hole count alone does not determine extraction, one expert argues[7] | You need a different dose range or a published tamper size |
| "Food grade" or "FDA approved" upgrades | Wording on a listing does not establish food-contact compliance[8] | The seller can document the claim |
A spinning distributor, if you already use WDT
Socratic Coffee compared the OCD and OCD 2, two spinning distributors, with no distributor at all, across three grinders. Both lowered strength (TDS) and extraction yield, and the differences were statistically significant (p < 0.01).[1] It is one study of one style of tool, and it did not test three-slope designs like the one we track. But it is the only controlled result we could verify, and it points the wrong way.
A needle tool works through the whole bed, which is where clumps are. Our needle tool vs distributor comparison covers the trade-offs.
A tamper bought for its force number
Socratic Coffee tamped shots at 5, 10, 15 and 20 kg, 10 shots each, and found no difference in TDS (p = 0.40).[2] Decent, which sells a calibrated tamper, says coffee is fully compressed at about 15 lb, and Normcore ships its spring tamper with three springs, 15, 25 and 30 lb.[6][9] No single number is the right one.
A spring-loaded tamper can still be worth it for consistency or a level tamp. Just do not pay extra for a particular force. Our tamper types guide explains what each mechanism controls.
An RDT sprayer, if you want better extraction
Socratic Coffee's 2024 test found no significant TDS difference with RDT, and shot times may have become less consistent.[3] RDT's real job is reducing static. If you have no static problem, you have no reason to buy a sprayer. See does RDT work.
A puck screen, if you want better taste
A puck screen keeps coffee off the shower screen, which follows from how it works. We found no controlled study showing that it fixes channeling or improves taste. It also takes up headspace, which can stop the portafilter locking with a full basket. Buy one for cleanliness, not flavor; see are puck screens worth it.
A 58.5 mm tamper as an upgrade
Bigger is not automatically better. VST specifies 58.40 mm for its 58 mm-class baskets, IMS gives 58/58.4 mm, Flair calls 58.4 mm the best fit for the Flair 58, and Decent advises against 58.5 mm.[4][5][10][6] Our 58 vs 58.5 mm guide explains when 58.5 mm makes sense.
A bottomless portafilter, if you want better flavor
A bottomless portafilter lets you see the underside of the basket while the shot runs. That makes it a good diagnostic tool. We found no evidence that it improves flavor by itself, and it brings a new risk: one made for the wrong group will not lock properly. See why a bottomless portafilter sprays.
What to buy first instead
- A scale. It is the accessory with the clearest case: in Socratic Coffee's tamping experiment, brew weight, not tamp force, drove the differences in strength.[2] Weigh the dose and the shot.
- A tamper that fits your basket. A gap at the edge leaves untamped coffee. Find your size in the basket and tamper size guide.
- A needle (WDT) tool. It is cheap, fits any basket and breaks up clumps through the whole bed. See what is WDT.
- A dosing funnel, if you grind straight into the portafilter or use WDT.
- The cleaning basics your manual calls for, such as a blind basket and detergent. See how to backflush.
Next
Questions
Do I need a distributor if I already use WDT?
No. In Socratic Coffee's 2016 test, OCD-style spinning distributors lowered TDS and extraction compared with using no distributor. Keep one only if you like it and your shots taste right.[1]
Is a calibrated tamper a waste of money?
Not if you value consistency, but the force number itself is not special: tamps from 5 to 20 kg gave no TDS difference in Socratic Coffee's test. A level tamp with a well-fitting tamper is what matters.[2]
What is the most useful first accessory?
A scale. Weighing dose and output lets you repeat a recipe, and in Socratic Coffee's tamping experiment brew weight, not tamp force, drove the differences in TDS.[2]
Are puck screens a gimmick?
Not entirely: a screen keeps the shower screen cleaner, which follows from how it works. Claims that it fixes channeling or improves taste have no controlled evidence that we found; see are puck screens worth it.
Is an RDT spray bottle worth buying?
Only if static bothers you. Socratic Coffee found no significant extraction difference with RDT. You can try the technique with a small mister you already own before buying a dedicated one.[3]