Why is aerated steam preferred to steam taken straight from the boiler?

Question

What will be an ideal response?

Answer 1

Aerated steam enables the root substrate to be pasteurized at a lower
temperature, usually 140-160oF rather than 212oF. The aerated steam temperature
is sufficient to kill the harmful organisms but allows more of the non-pathogenic
organisms to survive. The presence of non harmful organisms reduces reentry of
harmful organisms.