How did the experiments of Redi and Pasteur refute the hypothesis of spontaneous generation?

To refute the impulsive generation hypothesis many experiments were performed. The Francisco Redi, in 1668, verified that maggots appeared on meat only when there was exposition to the environment; within closed environments, they did not appear. In 1862, the Louis Pasteur working with swan- neck flasks refuted the abiogenesis hypothesis definitively. In this experiment Pasteur demonstrated that the boiled (to kill microorganisms) nutritive soups put in swan-neck flasks (with a curved down mouth so microorganisms could not enter easily) did not contaminate with microorganisms while the same soups within flasks with open upwards mouths were contaminated in a few days. In fact that both flasks were open refuted the argument of the vitalists that the vital elan could not enter the flasks. The Pasteur broke the swan-necks of the flasks to demonstrate that proliferation of microorganism could happen if these beings were able to reach the broth.