Which Coffee Scales Fit on an Espresso Machine's Drip Tray?
Summary
Three small scales are sold for use under the cup, the BOOKOO Themis Mini, the Varia AKU Mini and Decent's Half Decent Scale, and they stand 13 to 15 mm tall. The Acaia Pearl and Fellow Tally Pro are pour-over scales twice that height and much wider, and Fellow recommends against putting the Tally Pro on a drip tray at all. Among the three small ones, the choice turns on size, how wet each can get, and whether the scale talks to your machine.
Size, capacity and water rating
| Scale | Price | Size (W x D x H) | Capacity | Readability | Water rating |
|---|---|---|---|---|---|
| BOOKOO Themis Mini | $129.00 | 80 x 80 x 15 mm | 1,000 g | 0.1 g | IPX4 |
| Varia AKU Mini | $149.90 | 100 x 80 x 13 mm | 500 g | 0.01 g | IPX6 |
| Decent Half Decent Scale | Not listed on the product page | 158 x 103 x 14 mm | Not stated | 0.1 g | No rating; splash tolerant |
| Acaia Pearl | $150.00 | 160 x 160 x 32 mm | 2,000 g | 0.1 g | Not stated |
| Fellow Tally Pro | $199.95 | 177 x 150 x 33 mm | 2,500 g | 0.1 g | Water resistant, not waterproof |
BOOKOO pitches its 80 mm square as small enough for "even the tightest drip trays," naming machines from the La Marzocco Micra to the Flair 58. The Varia is 20 mm wider in one direction but 2 mm thinner, and it's the only one here that reads to 0.01 g, though its limit is 500 g. Varia rates it IPX6 and calls it waterproof, while BOOKOO rates the Themis Mini IPX4.
Decent's scale is the long one. At 158 mm wide it suits a wide drip tray more than a narrow one, and Decent's care guide says it is built for "the occasional splash," adding that "'tolerant' doesn't mean waterproof."
When the scale connects to the machine
The Half Decent Scale connects over Bluetooth, USB and Wi-Fi, and paired with Decent's DE1 app, "espresso shots will automatically stop at your specified in-cup weight." Decent publishes the code under GPL3 and calls the chassis, circuit board and firmware open. The BOOKOO works with apps including Beanconqueror, and BOOKOO lists Decent, Gaggiuino and Gaggimate among the machines it pairs with. Varia mentions Bluetooth only for software updates.
Fellow's reason for keeping the Tally Pro off the drip tray is its build. The company says the scale is "water-resistant, not waterproof," with an exposed USB-C port, and that it can still be used to weigh ground coffee in the portafilter.
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Sources
- BOOKOO — Themis Mini Coffee Scale
- Varia Brewing — AKU Mini Scale
- Decent Espresso — Half Decent Scale
- Decent Espresso — Half Decent Scale care guide
- Acaia — Pearl
- Fellow — Tally Pro Precision Scale
- Fellow Support — Is Tally Pro Precision scale suitable for brewing espresso?
We have not tested these products. Specs, prices, stock and terms are as published on these pages on the date above and can change; check the manufacturer or retailer before you buy.