A unit of measure (volume) introduced in the late 18th century. Roughly equal to a pint. In the 14th century. Grain, which pours --like water-- was in earlier times measured using liquid units, rather than by weight. In the 14th century is was measured by the quarter (290 liters) or bushell (36 liters). A liter of grain could, whether milled into flour and baked as bread, or cooked as grain for pottage, produce about 2,000 calories of food. While a liter was a unit of volume, the grain contained therein generally weighed about a pound. As a rule of thumb, a person needed about 500 liters of grain per year to sustain life.