TL;DR: Bao sái bàn thờ, the year-end cleaning of the family altar, is a ritual of wiping down the altar, trimming the incense sticks and rearranging the incense table to welcome Tết. It is usually done after the ceremony for ông Công ông Táo (the 23rd of the twelfth lunar month) and finished before New Year's Eve. By custom, the person who does it is the head of the household or a family member, washed and clean, never an outsider. The sequence has three steps: burn incense to ask permission from the deities and ancestors, wipe everything down with warm water or herb-infused water, then trim the incense sticks and leave an odd number of them in the bowl.
Title: Year-end altar cleansing: which day, who does it, and in what order?
What is bao sái bàn thờ and why must it be done at the end of the year?
Bao sái bàn thờ is the work of cleaning, rearranging the altar and trimming back the incense sticks before Tết, so that the place of worship is clean when the ancestors are welcomed home[3]. Vietnamese people do not regard this as ordinary housekeeping but as a spiritual ritual: descendants express their gratitude and respect to their ancestors and pray for a peaceful new year[2].
The incense bowl holds a very important place in the spiritual life of Vietnamese people, so on ordinary days, unless it is truly necessary, few people touch it. But after a year of worship, the incense sticks pile up. Folk belief holds that an overfull incense bowl is both hard to insert incense into and blocks the flow, affecting the fortune of the household head[3]. That is why at the end of the year, Vietnamese people usually perform the bao sái ritual.
According to cultural researcher Ngô Hương Giang, bao sái bát hương consists of four tasks: cleaning the altar, trimming the incense sticks, wiping the ritual objects and rearranging the incense table, all to be ready to welcome the new year[1]. The traditional view holds that this carries spiritual meaning and is not merely about making the altar clean: the household head expresses reverence and prays for the family to prosper[1].
Should the altar be cleansed before or after the ông Công ông Táo offering?
The common answer is to do it after the ông Công ông Táo offering. Cultural researcher and feng shui expert Phạm Đình Hải explains: folk belief holds that the altar and the incense bowl are where ông Công, that is the Thổ công (Earth God), and ông Táo, that is the Táo quân (Kitchen God), along with other deities, reside, so wiping and trimming the incense sticks is most appropriate once the offerings to send them off have been made[2].
Mr. Hải draws a clear distinction: bao sái differs from the everyday wiping of the altar or the cleaning done on the full moon and first day of each month. Bao sái, together with pulling and trimming the incense sticks, is like a "general cleaning" after a full year of worship. Therefore, in his view, before the ông Công ông Táo offering the household head need only tidy and arrange the altar; only after the offering is bao sái performed, and the incense sticks and incense ash are then burned after the votive paper has been burned[2].
Even so, this is not a rigid rule. A Buddhist page notes that people often do it in the last days of the twelfth lunar month, before or after the day of sending ông Táo to heaven; according to this page, what matters more is doing it at a time when one feels calm, unhurried and not irritable[4].
What is different at the end of the Ất Tỵ year (early 2026)?
At the end of the Ất Tỵ year, that is early in the 2026 solar year, there is one exception: Ất Tỵ is a leap lunar year and the Lập Xuân solar term of 2026 arrives right within the twelfth lunar month, so feng shui experts quoted by VietnamPlus advise household heads to perform bao sái and trim the incense sticks earlier than in other years[6].
Specifically, Ất Tỵ (the lunar year corresponding to 2025) has an extra leap sixth month and so lasts as long as 384 days. Lập Xuân is a marker of the solar calendar: it corresponds to the moment the Sun is at 315 degrees of longitude, which depends on the Earth's position in its orbit around the Sun. That lunar year is longer than the solar year, so it contains two Lập Xuân points: the first on 3/2/2025, the second on 4/2/2026, which falls on the 17th day of the twelfth lunar month of the Ất Tỵ year[6].
The feng shui world holds that performing bao sái and moving ritual objects after Lập Xuân easily causes "động khí" (disturbing the energy), making the worship space less stable. Experts therefore advise completing the bao sái and incense-stick trimming before Lập Xuân, and regard the period after the Rằm tháng Chạp (full moon of the twelfth lunar month) offering as the most suitable time[6].
Who should perform the altar cleansing ritual?
According to a guide by VietnamPlus, cleaning the ancestral altar should be undertaken by someone in the household, usually the household head, and the person doing it should bathe and cleanse themselves first. The article also recounts folk taboos: people who are injured, and women during their menstrual period, do not do this work, and during Tết one does not ask outsiders to cleanse the altar[5].
Cultural researchers also note: worship rituals require solemnity and a settled mind, so do not perform the ritual in sloppy clothes or while in a hurry[1].
What steps does altar cleansing involve?
Step 1: Light incense to ask permission
The first thing, before touching the ancestral altar, is to set out a plate of fruit and light a stick of incense to inform the deities and ancestors and ask permission to cleanse the altar along with the feng shui objects in the house[5]. In folk belief, touching and wiping without asking permission is considered a sacrilege that disturbs the deities[3].
The prayer text need not be elaborate: sincerity, reverence and a clear statement of what one is about to do are enough[4]. After lighting the incense, wait for it to burn out before beginning[6].
Step 2: Clean the altar
The VietnamPlus guide advises preparing a red brocade cloth or red paper: ritual objects are taken down and placed on it before being wiped, rather than wiped directly on the altar. The brush and cloth used for the altar are usually new and kept separately. Wipe the first time with clean, still-warm water, and the second time with white alcohol mixed with ginger or with ngũ vị hương water[5].
According to that guide, flower vases, water cups, bronze censers and lamps are lifted out for wiping, while the incense bowl and the ancestral tablets are left in place; the tablets are wiped with warm water or ginger-mixed alcohol, not cold water. If the altar holds tablets of both Buddhas and saints and of ancestors, wipe the Buddha's tablet first, pour out the old water, take fresh water, and then wipe the ancestral tablets[5].
People avoid cold water because they believe it is yin in nature and easily "defiles" the sacred place. Alcohol and herbs, meanwhile, are believed to purify and leave a clean fragrance, cleansing both the air and the energy[7].
Step 3: Pull and trim the incense sticks
Hold the incense bowl steady with one hand, and with the other gently pull out each incense stick, moving counter-clockwise, from the outer ring toward the centre. Pull them out gradually, ideally until an odd number of sticks remains in the bowl, for example 3, 5, 7 or 9. The removed sticks are gathered onto newspaper or a clean sheet of paper, and burned once the cleansing is finished[5].
Cultural researcher Ngô Hương Giang puts it more specifically: the Thổ công incense bowl keeps 5 sticks, the number of life; the ancestral incense bowl and the bà tổ cô incense bowl keep 3 sticks each. The trimmed sticks are burned in the votive-paper furnace, and the ash is taken and released into a river or buried under a large tree[1].
Once the altar is clean, the household head arranges the ritual objects back in their places, replaces the cold water in the cups, replaces the rice and salt in the jar if the house has one, and says a prayer to invite the deities and ancestors back[5].
Summary table: which day, who does it, what is done
| Item | Common guidance | Notes |
|---|---|---|
| Timing | After the ông Công ông Táo offering (23rd of the twelfth lunar month), before New Year's Eve | At the end of the Ất Tỵ year, feng shui experts advise doing it before Lập Xuân (4/2/2026), after Rằm tháng Chạp |
| Who performs it | The household head or someone in the family, bathed and cleanly dressed | Do not ask outsiders; women not during their menstrual period |
| Step 1 | Light incense, prepare fruit, ask permission of the deities and ancestors | Wait for the incense to burn out before starting |
| Step 2 | Clean with warm water, ginger alcohol or ngũ vị hương water | Do not use cold water, do not use strong chemical cleaners |
| Step 3 | Pull and trim the incense sticks, leaving an odd number (3, 5, 7, 9) | The Thổ công bowl keeps 5 sticks; the ancestral and bà tổ cô bowls keep 3 |
| Disposing of ash and incense sticks | Burn in the furnace, pour the ash into a river or bury it at the foot of a large tree | Do not throw it carelessly into the rubbish bin |
Taboos when cleansing the altar
According to the experts, there are several things people who cleanse the incense bowl often overlook[1]:
- Do not perform the ritual in sloppy clothes or while in a hurry.
- When wiping the incense bowl and ritual objects, avoid strong chemical cleaners.
- Once the incense bowl has been installed in place, do not move it elsewhere unless truly necessary.
- Do not let incense sticks pile up in the bowl over a long period.
Folk belief likens the incense bowl to the "home" where ancestors and deities come and go and reside, so custom strictly forbids moving it arbitrarily, especially turning it to face another direction[7]. However, according to cultural researcher Ngô Hương Giang, limiting the movement of the incense bowl is first of all so that the worship space stays stable and the household head keeps a sense of spiritual connection with the ancestors. The reason is not the idea that "moving the incense bowl loses fortune", as quite a few people speculate, but the keeping of ancestor worship solemn and continuous[1].
Throwing the ash from the incense bowl and old, broken ritual objects straight into the rubbish bin is considered disrespectful, so people avoid doing so. Incense ash can be scattered into a river or lake, or around the base of a tree in the garden[7].
Does merely "touching" the altar really lose fortune?
Bao sái should not be understood in an overly superstitious way. The Buddhist page states clearly: cleaning the altar with a sincere heart does not "disturb" anything or "lose fortune"; it is excessive fear and worry that unsettles the mind[4].
The incense bowl is regarded as a symbol connecting the living with the ancestors, so leaving it in place also preserves stability both spiritually and psychologically. Avoiding moving the incense bowl is therefore mainly a matter of belief and spirit, not a superstition that determines luck or official position[1].
When should the incense bowl be replaced or re-consecrated?
Many families also take the end of the year as an occasion to replace or re-consecrate the incense bowl. A new bowl should be sized to fit the altar, and the bowl for worshipping deities is usually the largest. The ash placed in the bowl is clean ash, allowed to fall in naturally rather than pressed down firmly. When all is done, the household head lights incense and performs a re-installation ritual to show reverence[1].
In any worship ritual, solemnity and sincerity remain the deciding factors. Cleansing the incense bowl properly both makes the place of worship clean and warm and helps the household head feel at ease and step into the new year with a positive spirit[1].
A suggestion from Nhật Nguyệt: if you have never cleansed the altar with your own hands, choose a quiet morning after the day of the ông Công ông Táo offering, prepare a new cloth, warm water mixed with a little ginger alcohol, and a clean sheet of paper to catch the incense sticks. Work slowly, step by step, and keep your mind calm. What matters is not choosing the most auspicious hour, but sincerity and solemnity in every movement.
