In such circumstances, storage of food is most important. The principal rule is to have separate places for different types of commodity: dry things can be kept in a pantry with bread and dry linen; wet things are normally stored in the buttery. Wine and meat must be kept apart, and cellars should be avoided on account of their dampness. Meat should be seethed in summer to keep it fresh, then kept in a cool cellar, soaked in vinegar with juniper seeds and salt. Most yeomen will have vats and presses for making cheeses—a valuable source of protein in the long winter season. Similarly, most livestock owners have troughs for salting meat or allowing it to steep in brine. What is the author's purpose in this excerpt?