The Elaion Facebook group is still going strong. A few days ago, a question came up that I did not have a detailed answer for: if you raise animals for meat as a modern Hellenist, how do you go about killing them? And can you store the meat? I wanted to answer the question when it came up but alas, time and lack of sleep prevented that from happening, so here is my (now researched) answer.

We often hear that the meat of sacrificial animals was consumed right away--and right on the spot--and often this was the case. It seems that the only available quantitative information on the amount of meat consumed by the average Athenian comes from 4th-century Athens, where epigraphic records show that a citizen had the opportunity to acquire meat from public sacrifices at least once every eight or nine days. With the amount of festivals that required animal sacrifice at this time, that would add up to roughly 40 to 45 times a year.

The principal kind of Greek sacrifice was called 'thysia' and consisted of the killing of a domestic animal, usually cattle, sheep, goats or pigs, followed by its division and sharing between the divine recipient and the human participants. The ritual steps to follow were strict, and while exceptions have been found both in literature and art, these ritual steps were very often observed:
  • Consecration if the animal to the God or Gods in question by a number of initial rituals at the altar. This often included 'prettying up'  the animal in some way. It could be washed, have its horns gilded and/or be 'decorated' with a wreath. As part of the consecration, a lock of hair was sacrificed in the fire.
  • Animals that resisted the procession towards the altar were not sacrificed. Watr was sprinkled on their heads before being killed, so they would nod their head 'yes', as a form of consent to the sacrifice.
  • The animal was killed by a blow to the head or the slitting of the throat.
  • If the throat was not slid before, it was done so now, and the blood was collected. Some blood was sprinkled on the front of the altar and poured into the fire.
  • The ololygē was practiced by women.
  • The victim was opened up so that the internal organs could be inspected, especially the liver. This would help identify if the meat was good enough to be offered and eaten.
  • The mēria was cut from the animal; the preferred sections were the thigh bones (femora) and the tail (caudal), vertebrae and the sacrum (the back part of the basin). These bones constituted the gods’ part of the sacrifice and Gods enjoyed their share by inhaling the thick, fatty smoke--'knise'--rising from the burning bones.
  • When the gods’ portion had been consumed in the fire, the animal’s body was butchered and the meat divided and distributed. The viscera were always cooked and eaten on the spot and consumed by the core group of participants who sponsored the sacrifice. The priests received some of the best parts of the animal as honorary shares, as did city officials and victorious athletes. The remaining meat was cut into pieces of more or less the same size and distributed to the population.
  • A thysia sacrifice was concluded by a meal of the meat, either in the sanctuary or the home, though on some occasions the meat was sold. What mattered was the sharing.
It appears that the meat was distributed either raw or cooked. It is unclear what the standard practice was, as everyone knew it at the time and it was subsequently rarely recorded. In the few cases where the condition of the meat is specified, Athenian decrees call for the distribution of raw meat, indication it was most likely not eaten on the spot. When the meat was distributed cooked, it was most likely distributed boiled. It appears that, in some instances, meat distribution was separated from the slaughtering by as much as two days, further evidence that meat (beyond the viscera) was not necessarily consumed right away. A two day waiting period would have allowed the meat to age and become tender, and it may also have made it easier to accommodate large crowds at the site of distribution.

The meat distributed to the public was cut into more or less equal portions, which means they were probably not equal in terms of quality. Status might have played a factor in determining who got which portion. It is generally accepted that the meat produced in large-scale state sacrifices was distributed to the male citizens of Athens, who in turn shared it with their families.

As a modern practitioner, the bare bones of the sacrifice (consecration - killing - blood sacrifice - ololegē - inspection - mēria - eating of viscera - distribution and/or preparation) can be observed easily enough if you are in the legal position to do so. Note that the sacrifice would have been practiced within the regular ritual structure (procession - purification - prayers/hymns - sacrifice - prayers of supplication and thanks - (feast)). The sacrifice would have been dedicated to one or more deities, and was done for a reason, even if it was to thank the Gods for the meat of the sacrifice.

Now, for the second part of that question: can meat be stored? Yes. There is evidence that meat was stored. Now I must nuance this. Sacrificial meat was not the only meat consumed by the ancient Hellenes. Even if we don't count fish, the ancient Hellenes ate meat from animals that had been killed at hunts, from species which were considered unfit for sacrifice and from animals that had died from natural causes. It is thus theoretically possible that the only meat stored were of this type. That said, ancient written sources do not uniformly describe meat as sacred, and raw meat could be taken home from a sacrifice. It would stand to reason that some of it was saved for later consumption.
At slaughter in family contexts to obtain meat for the dinner table as well as by butchers in the market would have most likely been accompanied by a more scaled-down version of the sacrificial structure presented above. Outside the sphere of proper sacrifice and simplified rituals there is evidence that animals could be killed and the meat eaten, though the Hellenes tried to avoid this meat. The fact remains that ancient Greek does not seem to have a term for slaughtering in a purely 'secular' context; all animals worthy of being sacrificed were sacrificed to the Theoi before the meat was distributed, sold or eaten, even at home, and even in the market square. It seems 'secular' in this case alludes to more or less ritualistic, not non-ritualistic.
Whom the household sacrifice was made to most likely depended on the reason for the sacrifice. Perhaps the household deities were the recipients if the sacrifice was conducted for no other reason than to put meat on the table. Perhaps it was Zeus, as King of the Gods. Perhaps, it was the God responsible for overlooking to profession of the male head of the household, so the family would continue to enjoy financial stability. In modern context, this should be no different; a sacrifice is made to ask for a blessing, or to thank for a blessing--whomever is responsible for that blessing varies.