This page is written for people who read spec sheets before they read reviews. It explains how the Coaster 2.0 measures a pour, what its real tolerances are, what happens when things go wrong, and what it deliberately does not do. There are no marketing adjectives below this line.
Where a figure depends on conditions (glass weight, pour rate, surface), the condition is stated. If a claim on this page ever disagrees with your bench test, tell us: contact@barsys.com — we'd rather fix the page than argue with your scale.
The Coaster 2.0 is a scale, not a dispenser. A load-cell array under the platform samples the mass of whatever sits on it continuously during a pour. When you start a recipe in the app, the coaster tares to your glass — any glass — and tracks added mass in real time as you pour.
Mass is converted to volume per ingredient using stored density values (spirits, liqueurs, juices, and syrups differ; water is 1.00 g/ml, a rich syrup is not). The light ring renders the running total: lit while you pour, signaling as you approach target, green at target. The intelligence — recipes, densities, sequencing, personalization — lives in the app and arrives at the coaster over Bluetooth 5.1.
Because measurement is by mass, the coaster does not care about pour speed, bottle shape, jigger technique, or whether you hesitate mid-pour. It cares that the glass stays on the platform while you pour into it.
Conditions that degrade accuracy, stated plainly: an unstable or vibrating surface; leaning on the counter mid-pour; lifting the glass off the platform while pouring; pouring so fast the stream splashes out of the glass. None of these are exotic — they're the same things that ruin a kitchen scale.
Measurement runs on the device, not the phone. The ring keeps guiding the current ingredient; the app re-syncs the ledger on reconnect. You will not lose a pour to a notification.
Small overshoots are rebalanced across remaining ingredients where the recipe allows it. Where it can't be rebalanced, the app says so and shows the corrected build — it never silently pretends the drink is right.
Unpowered, the Coaster 2.0 is an aluminum coaster. Nothing spoils, nothing leaks, nothing needs a reset cycle. Plug it back in and it's an instrument again.
The electronics are sealed inside the platform. There are no pumps, lines, or reservoirs to flush — the maintenance procedure is a cloth.
30-day returns, free US return shipping, full refund. Warranty claims are a replacement, not a repair queue.