Incense cones, sticks and coils: which burns how

The three common incense formats are not three versions of the same thing. They burn for different lengths of time, produce different amounts of smoke per minute, drop ash in different places and need different things underneath them. A cone is a short intense burn that leaves a cold ring of ash where it stood. A stick is a long slow burn that drops ash along a line. A coil runs for hours and needs suspending. Choosing wrongly is the usual reason a room ends up far smokier than anyone intended.

Cones: short, intense, and the only format backflow burners take

A cone is typically 25mm to 40mm tall and burns for roughly ten to twenty five minutes. Because the burning face widens as the flame front moves down, a cone gets smokier as it goes, which is the opposite of what people expect. The last third produces the most smoke of the whole burn.

That makes a cone the strongest format per minute and the one most likely to overwhelm a small room. In a bedroom, half a cone is often the right amount, and you can cut a cone in half dry before lighting it.

Cones are also the only thing a backflow burner will work with, and specifically hollow backflow cones, which have a channel up the middle for the cool smoke to fall through. A solid cone in a backflow burner will smoke upwards and the effect does not happen. If you are buying for a crescent burner, you want backflow cones and not ordinary ones.

The base of a burning cone stays hot after the smoke stops, and it sits in a ring of hot ash. Give it fifteen minutes before you touch it or tip it out.

Sticks: long, gentler per minute, and the ash problem

A stick burns from the tip downwards at a fairly constant rate, and the usual lengths run twenty to forty five minutes for a short stick and up to an hour or more for a long one. Smoke output is steadier than a cone's and lower at any given moment, which makes a stick easier to live with in a small room even though it releases more in total.

There are two constructions and they behave differently. A cored stick has a bamboo splint through the middle with paste rolled around it, and the splint keeps burning after the paste is used up. A solid or extruded stick is paste all the way through, usually thinner, and tends to be more expensive and less smoky.

The ash is the practical difference. A stick drops ash along its whole length as it burns, so it needs a catcher that extends under the full stick rather than a holder that only grips the end. A single hole holder with no tray will deposit ash in a line across whatever is behind it, and incense ash is oily enough to mark paint and leave a film on glass.

Holders built into an object are often shallower than a stick really wants. The brass carp has a well behind the dorsal fin that takes a stick, which is what the supplier makes it for, and like most object holders it grips the end rather than catching the ash along the length. Stand anything of that kind on a tile or a tray and the ash problem goes away.

Coils: hours, not minutes

A coil is a spiral of extruded paste designed to burn for anywhere from two hours to a full day depending on size. They are hung from a hook or supported on a stand over a wide ash tray, because the ash falls straight down from the burning point and the burning point moves around the spiral.

The length of the burn is the whole reason to be careful. A coil burning for six hours is a heat source and a smoke source that will outlast most people's attention, and that is exactly how incense gets left burning in an empty room. If you cannot stay with it, do not light the whole coil: coils snap cleanly and a quarter of one is still an hour.

They also produce the largest total volume of smoke of the three formats by a wide margin. In a one room flat, a coil is usually too much, and the thing it is actually good at is a large or well ventilated space over a long period.

What each format needs underneath it

All three need a non combustible, stable base that is larger than the thing burning on it. Ceramic, stone, cast iron and glass are all fine. Wood, painted shelves and anything laminated will scorch where the ash sits, and the mark is permanent.

A cone needs a flat dish or a recess that contains a ring of hot ash. A stick needs a long tray or a boat that runs under the entire stick. A coil needs a wide tray, wider than the coil, because the ash falls outward as well as down.

Clearance above matters more than clearance to the side, because the heat and the smoke go up. Nothing hanging overhead, no shelf directly above, no curtain within reach of a breeze, and at least 300mm of clear air above a cone or a stick. Backflow is the exception in one direction only: the smoke falls, but the cone itself is still burning upward and the burner's base still gets hot.

Smoke, residue and the film on everything

Incense smoke is oily. Over months it leaves a faint sticky film on walls, window glass and the top edges of picture frames, and it is noticeably harder to wash off than candle soot because it is resin rather than carbon. If you burn incense regularly in one spot, that spot is where the decorating will start.

The way to limit it is cross ventilation, meaning two openings rather than one, and burning less rather than burning something milder. Shutting the door to keep the scent in the room is what concentrates the residue in the room.

This is also the honest answer to which format suits a small flat. A short stick or half a cone, with a window open, in a room you are sitting in. Not a coil, not three cones at once, and not anything left running while you are in another room.

Safety, stated plainly

Incense is a lit ember at several hundred degrees with a column of hot gas above it. The format changes how long that lasts, not what it is. Never leave any of the three burning in a room you are not in, and never leave one burning while you sleep or go out.

Put it out properly rather than letting it run down. Press the ember into the ash or dip it in water, then leave the ash in the burner until it is cold. Ash that looks grey on top is frequently still hot underneath, and the usual accident with incense is hot ash going into a bin with paper in it.

If a smoke alarm goes off when you burn incense, the alarm is working correctly and the room has more particulate in it than you thought. Open a window and burn less. Covering or removing an alarm to use incense is the wrong trade.

Questions people actually ask

How long does an incense cone burn for?

Usually ten to twenty five minutes depending on size, and the smoke increases as it goes because the burning face widens towards the base. A stick runs twenty minutes to an hour, and a coil runs from two hours to a whole day.

Do backflow burners need special cones?

Yes. Backflow cones are hollow, with a channel up the middle that lets the cooled smoke fall through the burner instead of rising. An ordinary solid cone will simply smoke upwards and the falling effect will not happen.

Which incense is best for a small room?

A short stick, or half a cone, with a window open and a second opening if you can manage it. Cones are the most intense per minute and coils produce the most smoke in total, so neither suits a one room flat well.

Can you leave incense burning while you are out?

No. It is a live ember with hot ash under it and a hot column of air above it, and ash that looks cold on the surface often is not. Put it out before you leave the room, and let the ash go cold in the burner before it goes in a bin.