Back in the 1930's — and in the 1940's, too, for that matter — we had no electricity on our farm and, naturally, no refrigerator. Nevertheless, we enjoyed good, tasty food all.
One thing we did have was a cellar to store food without refrigeration. Dad dug a hole some four feet deep and about the size of a small room, built walls another foot or two higher with rock or slabs, placed beams and more slabs across the top, and covered the whole thing with dirt (except for the sloping entrance, which was protected by an inclined door). Our home–canned goods, vegetables, butter, and milk were kept there, and they always stayed cool in summer and free from frost in winter. Apples came from the underground storage area crisp and juicy.
The cellar was a great convenience, of course, but at various times of our life on the farm we made do with simpler arrangements. Once Dad made a trapdoor in the porch and dug a hole underneath, about two and a half by four feet, and deep enough to hold a roughly constructed box. During the summer months, we'd put our milk and churning cream in covered pails which we wrapped in wet cloths and lowered into the "cooler". Then we'd pour water into the box and let it drain out through the seams, so that the container and the surrounding soil were kept moist at all times.
The under–the–porch system worked very well. The cream came out of the cooler at a good churning temperature, and the butter we made from it was wrapped in a wet cloth and placed in the box, where it remained firm in the hottest weather. A bunch of lettuce or head of cabbage became crisper down in the hole than it was when we first brought it from the garden. Chopped salad vegetables, too, could be chilled there in a pan nestled in one damp rag and snugly covered with another.
In fact, on our place in the Southwest — where the air is dry and evaporation rapid — moist fabric used one way or another formed an important part of all our cooling systems, cloth covered watermelon, dipped in water and placed heavy shade with a bit of a breeze blowing, was chilled more thoroughly than one set in running water.
Pitchers of milk or lemonade were treated similar wrapped in clean rags, set in a pan of water, and placed for hour or more in a window where cross-ventilation was present If we left the jugs overnight, they'd be downright cold in morning. (In fact, that's how we used to set Jell-O.)
A cooler we had at one time — a screened–in box with a door — made use of the same principle on a larger scale. Cloth covered the screen and was anchored at the top in a tray water, which seeped into the fabric like oil into a wick. above the tray was a tank with a float mechanism to keep the water level constant. And, yes, the food inside the box stayed cook One of our neighbors had the simplest cooling method all He just poured fresh milk, warm from the cow, into a pot with a tight cover, tied the bucket to the end of a rope, an immersed the whole business in his well. Milk never tasted better. (Be sure to use a watertight container if you try tip trick, unless, of course, you like the flavor of sour dairy products in your drinking water.)
Quick cooling goes along way toward keeping milk sweet but the use of sterile utensils is more important still. All our dairy equipment — including the parts of the cream separator — was thoroughly washed in soap and water. We scoured the milk pails, if necessary, and carefully rinsed them to prevent any residue from encrusting the insides. Then we boiled all the articles and set them in direct sunlight until they were needed again.
Now that I come to think of it, I suppose our cooling were all terribly inconvenient. We didn't know it right the time, though, and managed to be thoroughly happy healthy without the blessings of mechanical refrigeration.