Most owners have no clue how much they waste until they write it down. So keep three logs. One for spoilage, when stock goes bad. One for prep waste, like trim and over-cooking. One for plate waste, food that comes back or never sells.
Two weeks of honest notes is usually enough. One or two items will turn out to cause most of the loss. Restaurant inventory software keeps this going for you. Each entry gets a reason, and the weekly report shows where the money goes.
