In reference to the patent: US3228773
This is a common practice so if it is patented does this mean that no one else can use this process? That's absurd.
The patent you refer to expired back in 1983 or so. Any time after that, the teachings are considered public domain.
Recall that many patents - especially in the titles, abstract and descriptions - sound insanely obvious and trivial. And indeed some are!
However, it is the 'Claims' that determine the scope of what is legally excludable, and these are often highly specific.
For instance in this Tempeh patent, it is for a particular growth medium (which may have been newly discovered in 1963 - I don't know), for a particular time, in a particular kind of vessel at a particular temperature. In principle, someone doing some but not all of these things at once, would be free - even back then - from infringement. Usually all the elements of a claim have to be considered, not just some. And the title and abstract really mean nothing.
Hope this helps.
Common practices performed by individuals / technicians in a field "having ordinary skill in the art" are NOT patentable--because these things are obvious and not-novel. The criteria for patenting are that the invention MUST be at least:
The specific claims written by the inventor(s) must be defended against thorough examination. The examiner is paid / tasked with finding faults in the patent application so it can be "disallowed".
In order for the patent to be eventually "granted" to the inventor(s) the examiner must have examined the specification and claims and be unable to find serious fault that would prevent "allowance" of the claims.
That said the inventor can use any language in their patent specification they desire so long as the invention they claim (patent claims) at least meets all of the above criteria (and naturally the other baseline criteria for having a fully complete specification) [edited].