Is there a halachic objection to human composting?

Question

I just had a discussion with a friend about this organization, which proposes to inter human bodies in a giant composter (from which the family can retrieve the compost later) instead of burying them in individual graves. Would this be a kosher burial (or could it be kosher under the right circumstances)? If not, why not?

EDIT: It's been suggested that this question is a duplicate of this one. It's not. That question is about cremation. This one is not about cremation. They are both about the appropriate treatment of human corpses, but cremation and decomposition are completely different situations, and it doesn't make sense to generalize from one to the other. Thus it's not a duplicate, QED.

Answer 1

Make fertilizer with a deceased body...

A quick outline of answer, or rather a strong intuition. First: facultative references copied from massoret Hashass Chulin 122a (each page is for the Tosfot primarily)

Chulin 122a

Mishnah:…if any of these skins was tanned or trampled upon as much as [was usual] for tanning, it becomes clean, excepting the skin of a man. R' johanan b. nuri says, the eight reptiles have [real] skins. Gemara Ulla said: According to the law of the Torah the skin of a man is clean, but for what reason did they say it was unclean? As a precautionary measure lest a man make rugs out of the skin of his father and mother.

Zevachim 71b

Nidah 55a

Baba-Kama 10a

Arachin 4a

Sanhedrin 48a

Rabeynu Tam explains that despite that a dead is banned from profit, Chachomim decreed an uncleaness because people are attentive to uncleannes more than that are attentive to ban

See Tosfot Sanhedrin 48A, the first of the page. 1) make profit from human body is banned 2) Chachomim made a special effort to reinforce the obedience 3) The concerning with the body of deceased father for the riding , donkey is pointed by the Gemara (Ula, Chulin 122A) this is a signpost. The concerning with bodies ... does that ring a bell? ... crematory oven. My quick hunch is that they want to deny the respect of mankind. The sages of the Talmud know how to teach through clear allusions (riding, donkey) what is hidden (consciously or unconsciously) beyond human behavior, a desire to humiliate, to deny. (remember that when father and mother are alive, there is strong mitsva to honor and fear them).

Answer 2

The body must be buried without being cut up. Even an autopsy should be avoided if possible. Composting which is the treating of a body as if it is garbage to be disposed of is most similar to cremation.

If some of the limbs were severed and left unburied, the Mitzvah of burial is not fulfilled, as ruled in the Jerusalem Talmud, Tractate Nazir 33a.

For example The Interment By Maurice Lamm

Jewish law is unequivocal in establishing absolutely, and uncompromisingly, that the dead must be buried in the earth. Man's body returns to the earth as it was.

The blood and limbs of an individual are considered by Jewish law to be part of the human being. As such, they require burial. If the deceased was found with severed limbs, or with blood-stained clothes, both the limbs and the clothes must be buried with him.

If limbs were amputated during one's lifetime, they require burial in the person's future gravesite. If he does not own a plot as yet, or if he is squeamish in this regard, it should be buried in a separate plot, preferably near the graves of members of his family. The limbs are cleansed and placed in the earth. No observance of mourning is necessary.

Donation of Limbs to Hospitals

Jewish law generally discourages contribution of one's limbs to hospitals. If one has absolutely stipulated that a limb be donated for medical research, the question of following his will depends on many details, and requires rabbinic research. It is best, therefore, to consult an expert on Jewish law. At any rate, even if it were permitted, the limb would require burial when it is no longer in use by the medical institution.