A Whiskey Thief is a tool that Master Distillers have used for hundreds of years to extract small portions of whiskey from an aging barrel for sampling or quality control.  They are typically made of copper and resemble a drinking straw in design with their coned narrow hole at the bottom and vent hole at the top.  Once the device is inserted in the barrel, a distiller can cover the vent hole at the top with their thumb and trap and lift the whiskey out of the barrel. By removing the thumb from the upper vent hole, the whiskey is released to drain into drinking glasses for tasting.