Well if by publishing you mean "mass printing and distribution with equipment owned by an ordinary person" then sure, it was impossible. That's a very careful, laser focused definition, though. Publishing universally means going to the publisher and getting through the entire process, not owning a typography. That's what you did in the USSR, with the censor as the additional step (main step, actually).

My dad had a bunch of samizdat books and periodicals. Some were typed on a typewriter, some were printed on a dot matrix printer (closest to what you can call directly accessible mass printing in the USSR). None of those were recipe books, these were all texts impossible to publish.