Nutritious soup

A pound of Scotch barley, with sufficient time allowed in the cooking, will make a gallon of water into a tolerable pudding consistency. A pint basin filled with it will hold a spoon upright, when at its proper degree of warmth for eating. Thoroughly steeped, it will produce a rich pulp, the form of the grains being nearly lost. Five hours' exposure, in a moderately heated oven, will be sufficient; and it may be improved by an hour or two more.

Amongst other means for such preparation, when a baker's oven has been emptied of its bread a pan of 1 gallon size may be put in to steep its contents during the preceding night, and then renew the usual baking in the morning. What has been lost by evaporation, may be restored by the addition of warm water. All the seasoning requisite to make it as savory as plain family dishes generally are, will be about 3 large onions, 1 ounce of salt, and 1/4 of an ounce of pepper. This seasoning should be put in before sending it to the oven.

see Wikipedia Cookbook