Calibrated tampers help you get more consistent tamping as a beginner. If you’re using a regular, old-school tamper with no spring mechanism, start with 15 pounds of pressure and then apply 20-40 pounds once the puck is formed. You can stand on a scale to watch your weight. If you don’t tamp hard enough, you may leave holes and create channeling. Some say tamping too hard also creates channeling, while others say there’s no such thing as tamping too hard if you have quality coffee beans.
