Here is a simple way to keep food cool in the summer. I found this in an old book on farming. A plastic or metal barrel or a waterproofed wood box could be used in place of the wooden barrel.
A very convenient and serviceable place to keep dairy products may be formed by sinking a large barrel in the ground. A shady spot should be chosen, or the heat of the sun will affect the temperature.
Fill in around the barrel with small stones, gravel and sand, dampened in order to maintain coolness. Construct a box around and above the top of the barrel, and bank up with solid earth, preferably clay. This drains off the water when it rains. It also makes the bottom of the barrel farther down from the top of the opening, which further promotes coolness. Next, shape a light, inner lid to place on top of the barrel, and then make a strong, hinged lid for the box, and arrange it so it may be fastened down tightly.
Sprinkle a little dampened sand on the bottom of the barrel, and your little barrel cellar is ready for use. By being careful several vessels may be arranged one above the other in this handy little receptacle. Air out occasionally to prevent mold and odors from collecting.