Synthesized from owner reports and published reviews; our own testing notes will replace this as they mature. We sell this scale, so read us skeptically.
The short version
Ask what brew scale to buy under $100 and the answer has been some version of the Black Mirror for years. It weighs to 0.1 g, reads quickly while water is moving, and includes a timer. Owners' complaints are small and consistent, which is what you want from a $55 tool.
What owners consistently praise
Response speed for the price: pours register fast enough to manage flow by feel, where cheap kitchen scales lag seconds behind. The auto-tare and timer workflow covers pour over and immersion without menu-diving. Reviewers comparing it against scales at three times the price keep concluding the extra money buys espresso-app features, not better brewing measurements.
Where it falls short
The auto-off default will shut the scale down mid-French-press if you don't change the setting, the top is splash-resistant rather than waterproof, and there's no Bluetooth logging or flow-rate-by-weight display; if you want your shots graphed, that's the expensive aisle. A few owners note the battery indicator is vague.
Who it's for
Anyone brewing by ratio, which should be everyone. If you're deep enough into espresso to want shot profiles on your phone, you already know you're shopping for a different scale.
Sources worth your time
Tom's Guide review · Barista Magazine test drive · The Coffee Chronicler