This is from my old blog, the Geekie Hellenist.
This ritual is dedicated to Demeter. The information for this festival was very easy to find, thank the gods. But I’m also adding Poseidon to this as this was around the time that sailors would start setting sail, and I think that it’s appropriate. So I’m going to be adding two invocations, instead of one, and they will be to Demeter and to Poseidon. I hope that this helps you out and that you can use it. To give some background info before I start Haloa was dedicated to the goddess Demeter.
Now most will look at this and wonder why we would honor Demeter when it’s freaking cold outside. The climate is different in Greece than here in the States. So while we’re shivering, the Greeks are honoring Demeter and asking for her to make their crops grow. Even though we might find it odd, I don’t. And I’m going to honor her and ask for thanks for what she has allowed to grow. Well, onto the ritual.
1) Purify the Altar area.
2) Take the barley and say, “As it was done in ancient times. I purify and cleanse this altar with this barley. With this barley I purify this altar and space so that I may give offerings, libations, and speak with glory and respect the gods of Mt. Olympus.”
3) Light a candle and say a hymn to Hestia.
Hestia, you who guard the sacred shrine of the Lord Apollon. The far-darter at goodly Pathos. With soft oil dripping ever from your locks. Come now to this house, come having one mind with Zeus the all wise-draw near, and with all bestow favor upon my song.”
4)Prayer to Hestia
Hestia, gracious goddess who sits at the heart of each home, who lives in the heart of each one who reveres you, each one who holds you dear, each one who turns to you for strength and harmony.
Hestia, goddess most needful, goddess most serene, goddess most esteemed, the heart of the city is yours as well, great goddess; within your realm are those who serve the state, who work for all the good of all–your blessings fall on the honest, goddess, your wrath on the corrupt, on those who betray their trust for gain. Defender of the householder, guardian of the hearthfire, Hestia, I praise and honor you.
5) Let Demeter and Poseidon know that your here by saying, “Demeter, hear me” and “Poseidon, hear me.” This isn’t a command, this is letting them know that your here. Then tell them which offerings, if any, that you’ve made to them. Also let them know of any thing that they’ve done for you. It’s a kind reminder that you still remember what they’ve granted you and what you’ve offered to them in the past. Now tell them what you intend to give to them and make sure that you have the offerings there.
6) Say the invocation to Demeter
“I call to Demeter, great lady of the land, friend of the farmer, sustainer of mankind, daughter of deep-hearted Rhea and wily Kronos, loving mother of rich-tressed Persephone.
In ancient times were you honored by country folk above all others; in all the provinces did men and women pray to you and ask your blessing.
Goddess, we see your hand in rows of golden grain, in heavy-fruited trees, in fields of scarlet poppies blooming amongst the barley, in the passing of seasons, in the fury of a mother wronged.
Demeter, lauded in storied Eleusis, mistress of those cherished mysteries and scared rites, by your might and your compassion do we endure, do we live our lives. Demeter, I call to you.”
7)Say the invocation to Poseidon
“I call to Poseidon, great god of the seas, fond husband of ocean-dwelling Amphitrite, son of ancient Kronos and wild-hearted Rhea, father of noble kings and mighty heroes.
In distant days were you well known; in Crete your name was carved in clay; in Corinth were you honored well, and in all the provinces.
Dark haired Poseidon, you hold in your hands the waters of the world, those briny depths that brought us all into life; that carried mankind to many lands, to gather wealth and wisdom; that nourished our furthest forebears and formed the patterns of our lives.
Poseidon, maker and master of horses, trident-bearer, earth-shaker, lord of the beasts of the deep, lord of the thrashing waves, sea-god, I call to you.”
8) Do a Hymn to Demeter
“I begin to sing of rich-haired Demeter, awful goddess, of her and of her daughter lovely Persephone.
Hail, Goddess! Keep this city safe, and govern my song.”
9) Hymn to Poseidon
“I begin to sing about Poseidon, the great god, mover of the earth and fruitless sea, god of the deep who is also lord of Helicon and wide Aegae. A two-fold office the gods allotted you, O Shaker of the Earth,  to be a tamer of horses and a saviour of ships!
Hail, Poseidon, Holder of the Earth, dark-haired lord! O blessed one, be kindly in heart and help those who voyage in ships!”
10) Give offerings to Demeter, saying, “Lady Demeter, giver of life, taker of life, founder of the Mysteries, Sister to Zeus, and any other titles that you believe are connected to her, I give this offering of incense and food.”
11) Give offerings, saying, “Lord Poseidon, Lord of the Deep Oceans, Middle of the Three brothers, earth shaker, lord of horses, and any other titles that you believe are connected to her, I give this offering of incense and food.”
12) Say a prayer to Demeter
Fair-haired Demeter, daughter of nimble-footed Rhea, grandchild of deep-hearted Gaia, mother of bright-eyed Persephone: in you, as in them all, is the soul of the earth.
The golden grain is yours, O Demeter, and the heavy fruited trees, the dark rich soil and the seeds that hide within.
Friend of the farmer, friend of all who rely on your goodness and kindness, your gift of growth, your gift of bread, your gift of all our lives.
Demeter, bountiful lady, with each spring’s greening of the land you give us hope; with each rich harvest that hope is answered.
Demeter, good mother, I praise you.
13) Say a prayer to Poseidon
Deep-dwelling Poseidon, shield of sailors, stiller of storms, shaker of the earth beneath us, I praise you.
Well known you were in days of old, honored above all others in far-famed Corinth; your temples stood throughout the ancient lands, each floor well polished by the feet of the devoted.
In times still longer past, still further lost in time, were you among the first of gods whose names were known to men, the first whose might was honored, the first who answered desperate please with dear blessings. Poseidon, whose voice we hear in the crash of waves, whose hand guides the fate of all who venture out upon the sea, to whom we owe thanks for transport and trade, for salt fish and sweet water, I praise you.
14) Say your own prayer to Demeter and/or Poseidon. This is different than the prayer that I have listed, as this is your own personal time to spend with them. If you live in a part of the world where crops are being planted then you can ask Demeter if she will help your crops grow. If your by the sea you can either thank Poseidon for what he has kept from happening to your town or you can ask him for good sailing. Or you could just pray and say thanks, whatever you want.
However, this isn’t like Wicca. You can’t demand things from either Demeter or Poseidon. That’s not how the gods work.
15) Pour libation to them. Remember the first libation belongs to Hestia as does the last.
16) Finish the ritual by doing a closing prayer to Hestia.
End the ritual by saying, “Hestia, goddess of home and hearth, to you I offer last of all as a pious mortal should. Tend to those whom I love and guard the houses of the pious. As the gods will it, so it shall be.”
It is so!
Dump the entire container that you’ve poured your wine or grape juice into outside and then that ends it.