You will find that light bread will not
sour so quickly in summer if it is not covered when taken from the oven.
This steam is unnatural and should be allowed to escape or it soaks into
the bread, making it clammy and more liable to sour. Let the bread cool
gradually then put a clean cloth in a large stone jar, place the bread in
and cover with the cloth, before covering with the stone, or wooden lid.
This keeps bread fresh and moist from one bake day to another.