Parasitic worms are huge, complex multicellular animals that co-evolved to sometimes survive the immune system response to their presence; Freezing kills them because they are huge and the scale of ice crystals severs important body parts. Living bacteria, living fungi, spores from these, viruses, and importantly heat-resistant toxins produced by these, are what I'm worried about.

One of modern humanity's oldest activities is fermenting carbohydrates in large bioreactors into alcohol, yogurt, and pickles, but there are a lot of things that turned out not to work in that history.

When we try to fabricate, say, monoclonal antibodies using large cultures of multicellular tissues for pharmaceutical work, the price ends up coming out to millions of dollars a kilogram.

I am implicitly skeptical of the protocols of a protein tissue culture that has to be produced at the ~$30/kg price level.

Could you eat it and not die? I'm sure!

But could you feed people with a billion meals worth of batches and have nobody die? I'm less sure! My understanding is that tissue culture failures are frequently the bane of a biologist's research program.