How households kept butter and milk cool and fresh early century
Perishable foods though were a different matter, as there were no fridges when I was a child. So my mother always had to take steps in the summer to keep perishable food in good condition.
Perishable food such as meat, milk and butter were kept in the food safe, but it was still a problem to keep them fresh in summer months. So my mother had to resort to other measures:
Butter was a problem too in the hot weather because it went rancid so quickly. To keep it as cool as possible, my mother covered it over with a basin and then covered the basin with a flannel. Then she put the butter, basin and flannel in a shallow pan of water so that the ends of the flannel dipped into the water. The evaporation of the water kept the basin cool and hence also kept the butter cool.
Often instead of a flannel, a piece of muslin or a crocheted circle was used, kept weighted down with beads sewn round the edge.
Milk was kept cool in the same way with a beaded fabric circle placed over the jug in a shallow dish of water.
However - and it was a big however, although these arrangements normally worked well, they did not when the weather was humid, like in a heat wave before a storm. Then the water wouldn't evaporate, so the butter and milk weren't cooled and they went off.
Then my mother had to resort to other measures:
Scalding milk to stop it souring
In very hot and humid weather, when the milk cooler didn't work, my mother 'scalded' the milk to make it last longer. This involved heating the milk in a saucepan to near boiling point and letting it cool. Doing this wasn't ideal, though, because it took the substance out of the milk and made a skin form on top. I very much liked the skin but most people didn't. Also if the saucepan was not quite clean or if the heat was too fierce, the milk took on an unpleasant burnt taste.
Fortunately the dairy might make several deliveries each day in summer, but even so, I would sometimes be sent along to the dairy with a jug to buy more milk because what we had had gone sour.
Keeping meat fresh in hot weather
Meat could be kept in some form of butter cooler in hot weather, but when the humidity was high and the water in the cooler wouldn't evaporate, the meat would still go off. Many a time I saw my mother wipe the Sunday joint over with a vinegar rag before cooking it because it was beginning to smell.