Put
a wet piece of bread (with approximately 20 water drops) in a
closed bag and hold the bag for a week in a warm dark place.
Observations
1th day:
nothing happens
2nd day: nothing happens
3rd day: on the soft part there is
a small grey-green-whitish spot (mildew)
4th day: the spot is larger; there are some
green dots also on the crust
5th day: the mildew has expanded
on the soft part and on the crust
6th day: all the soft part has assumed
a grey-green colour
7th day: the mildew spots have filled
up all the surface of the bread
Conclusions
The spores of the mildew
are everywhere in the air and therefore they are also
on the bread. With an adapted atmosphere (warm, dark, humid)
they proliferate.