Lunar

Channelling is usually something you diagnose after the fact, from a sour cup and a shot that finished four seconds early. The Lunar puts it in front of you while it is still happening.

The Acaia Lunar stands 15 millimetres tall, low enough to sit on the drip tray under a portafilter without lifting the cup towards the spouts. Above its eight-digit display runs a bar of LEDs that reads flow rate live through the pour, lighting from 0.1 grams per second at the left end to 3.4 at the right, with the last three LEDs brightening once flow passes 5.0 g/s. Through the shot, the single brightest LED holds at the fastest the coffee has run, so a channel reads as a bar that jumps rather than a number you reconstruct afterwards. Lift the cup off and the display flashes the final beverage weight beside the average flow rate for the whole brew. Tare Save stores the weight of a regular dosing cup, so the scale opens at zero with the cup already on it.

The body is anodised aluminium and acrylic, and Acaia expects it to get wet: the scale reads to 0.1 gram with a 0.01 gram setting available, charges over USB-C, and sends its data out over Bluetooth 5.0. Washing is warm water alone, though, because detergent attacks the anodised coating. That is the trade for a scale thin enough to live permanently where the water lands.