The exact history of the beginnings of the ayahuasca ceremony is unclear however it is known to have been used for hundreds if not thousands of years by shamans all over Southern America, particularly in Ecuador, Columbia and Peru. The ceremonies themselves can be very intricate and their processes are passed down through generations of medicine men. The Shipibo shaman of the Upper Amazonian jungle in Peru are some of the most highly sought after leaders of ceremony as they maintain their spiritual connection with the plants of the jungle and live their lives such as their ancestors have done for thousands of years. Ayahuasca is used for its divine healing properties and for it's divination abilities as it is a hallucinogenic.
The brew used in an ayahuasca ceremony is made up of both the sacred star shaped ayahuasca vine (Banisteriopsis caapi) and the leaf of the chacruna plant (Psychotria viridis). It is the leaf of the chacruna which contains the DMT that leads to psychoactive hallucinations but without the chemical make up of the ayahuasca vine the body would not allow it to penetrate the bloodstream and brain. It is uncertain in a jungle containing thousands of different plants how the brew first was discovered and made.
image by http://julianpalmerism.com/
An ayahuasca ceremony is not to be taken lightly and if conducted properly with a legitimate shamanic leader many weeks of preparation beforehand must be strictly adhered to. It is known that there are many performing these rituals to tourists in the jungle who do not follow any safety guidelines which leads to many deaths.
Shamans first only used this brew on themselves, as shamanic initiation, they used it to strengthen their connection to the spirit realm and to forgo shamanic journeys on a deeper level. They can communicate stronger with the spirits in an hallucinogenic state, diagnose illness in their patients, solve conflicts and ask the plant spirits for the perfect remedy for illnesses. Shamans now conduct these ceremonies for others as a form of healing as it is used to expel any negative human emotions and blockages in the spiritual and physical bodies.
Typically in a 'real' ayahuasca ceremony only the shaman will drink the brew. The hallucinogenic properties as a divinatory tool allows them to see any entities, illness and blocks whether emotional, physical or spiritual in a patient and the plant spirits will lead them to the perfect cure or plant remedy for each person seeking help. In a modern day ritual known in the western world all participants drink the brew in a ceremony led by a practiced shaman so the process is conducted in a safe manner. This acts as a purging ceremony.
There is no one way to lead and conduct an ayahuasca ceremony but they usually follow the same typical process. All participants must follow a strict dietary regime in the weeks leading up to a ceremony to prepare their bodies and mental state. Most ceremonies will be conducted in a private space, sometimes outside, where all participants sit or lay on the floor or on mats in a circle, sometimes surrounding a central fire. Groups are usually kept small so everyone can be watched closely and kept safe.
Image by http://www.medicinehunter.com/
A shaman will open the ritual with a cleansing and prayer, sometimes song or drumming. Herbs can be burned in the fire. Each person drinks from the pre-brewed ayahuasca mix, only a little bit as it is quite strong. The shaman normally doesn't drink in this case or if they do there is normally another one or two people to keep watch on the others. The process usually begins with quiet time and reflection before the hallucinogenics begin to take affect. The shaman leads the group in a meditation and takes the individual inwards to inner reflection. Their can be singing, dancing or any other form of release throughout this process. The whole ritual can take a few hours.
As this is a purging normally buckets are placed beside each individual and most participants will naturally vomit after consuming the brew. Through the act of purging participants are delving deep into their sub conscious minds and bodies and releasing all roots of energetic blocks created by fear, shame, addictions, regret, pain and any other shadow aspects of their former selves. Upon completion of the ceremony and when the brew begins to wear off they are often feeling lighter and freer straight away. People go back to their lives with personal fulfillment and more self control.
This is just the tip of the ayahuasca iceberg. I have read many books and information on the subject, some by shamans and their stories are quite amazing! If sacred plant medicine is something that interests you I advise you to research this topic it is very interesting. Please only take part in a ceremony led by a professional so you are watched and kept safe at all times.