Lighting and putting out binchotan

Updated 2026-08-29

How do you light binchotan, and how do you put it out?

Light binchotan slowly in a chimney starter over a flame, outdoors only, and put it out in a lidded hikeshi-tsubo rather than with water, which also cracks a diatomite konro.

Binchotan isn't hard once you know the two rules. It's slow, and almost every mistake happens in the first ten minutes of lighting it or the last ten minutes of putting it out. I've spent years in the Japanese-goods trade, and this is the routine I actually use: it burns outdoors, full stop, and it never meets water.

Why binchotan is hard to light

Binchotan is fired so hard that it ends up close to pure carbon, and that density is the whole reason a match does nothing to it. It's made from ubame oak, carbonised slowly in a kiln and finished at around 1,000°C, then raked out glowing and smothered in a damp mix of earth, sand and ash to cool. That pale coating is where the name white charcoal comes from. Knock two pieces together and they ring like metal instead of knocking like wood.

You get something back for the trouble. It holds a steady heat for hours, it barely smokes, and clean binchotan doesn't put any smell into the food.

One thing to sort out before you strike a match: binchotan that has taken on moisture can pop. The Japanese word for it is bakucho. Water trapped inside a piece flashes to steam and splits it open, and hot fragments fly. Keep the bag closed, store it somewhere dry, dry out any piece that got damp, and bring the fire up slowly. Once a piece is glowing red it has stopped being a problem.

How do you light it?

Light it slowly, outdoors, in a chimney starter sitting over an existing flame. Never straight off a firelighter alone, and never on a portable butane cartridge stove, where the gas canister sits right next to all that heat.

Load the chimney loosely so air can move through it. Put a couple of firelighters or a decent handful of ordinary lump charcoal underneath. Give it about ten minutes before you expect to see much; that's roughly when the first third of the load starts to catch. Then fan it, gently, and keep going until the pieces glow and begin to grey over. Fifteen minutes in the chimney is normal and longer is fine. If you're bringing binchotan up on a bed of existing embers rather than paper, start an hour before you want to cook.

Two habits that save you. Don't rush it with a torch on full. And don't tip half-lit pieces into the grill hoping they'll come good, because they won't, and cold pieces are what smoke.

How do you set up a konro for two-zone cooking?

Bank all the lit coals under one half of the konro and leave the other half empty. That's the whole trick, and it's what makes a small grill workable.

A konro is usually cut or pressed from diatomite, which is fossilised diatom shells, mostly silica. In Suzu on the Noto peninsula they cut it out of the ground in blocks, carve it, and fire it in a kiln for about a day and a night. Diatomite insulates well, which is why the body doesn't heat up the way metal does, though it still gets hot close to the fire, so don't assume any part of it is safe to grab.

Hot side: skewers, the first sear, anything with fat on it. Empty side: where you park something to finish through, and where a flaring skewer goes. Binchotan has little left in it to burn off, so flare-ups are less common than with regular charcoal, but they still happen, and having somewhere to move to beats blowing on it.

Height matters more than people expect. Sit small skewers close to the coals and lift a thick piece higher. If your grill has two rack positions, use both.

How do you put it out and use it again?

Lift the coals out one at a time with tongs into a hikeshi-tsubo, put the lid on, and walk away. The fire goes out because the air runs out. Leave the lid shut until the charcoal is fully out, which usually takes a good while, and stand the pot on something that doesn't mind heat, because the base gets very hot.

The reason for a pot rather than a bucket is that binchotan relights. What comes out the next morning is fuel, not waste, so this is the cheap part of owning it.

What you never do is throw water on coals sitting in the konro. Ash goes everywhere and the steam will scald you. The sudden temperature drop can also crack the body of the grill. Diatomite is very weak to water, so you don't wash a konro at all; knock the ash out once it's cold and leave the marks on it.

Is it safe indoors or on a balcony?

No. Charcoal burns outside, in open air, every time. NSW Health says never to use a BBQ or an outdoor heater inside, because any device burning fuel can make carbon monoxide even when there's no smoke. Carbon monoxide can't be seen, tasted or smelled. It shows up as headache, nausea, vomiting or weakness, and a heavy exposure means fainting, permanent brain injury or death.

Treat an enclosed balcony, a garage with the door up, or a room with a window open as indoors. None of them count as open air.

If you live in an apartment there's a second question, and it isn't a safety one. Strata by-laws vary from scheme to scheme, and plenty of buildings have a by-law covering barbecues and smoke drift on balconies. Ask your strata committee secretary or manager for your scheme's by-laws and read them before you buy a grill. I can't tell you what your building allows. I can only tell you it's written down somewhere and worth reading first.

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The process

  1. Check the charcoal is dry. Damp binchotan pops when it heats, so dry out any piece that has been in a wet bag or a cold shed.
  2. Set up outdoors, in open air, on a surface that doesn't mind heat.
  3. Load a chimney starter loosely so air can travel up through the pieces.
  4. Put firelighters or a handful of ordinary lump charcoal underneath and light that, not the binchotan. Never use a portable butane cartridge stove as the heat source.
  5. Wait about ten minutes. Around then the first third of the load starts to catch.
  6. Fan gently and keep going until the pieces glow and start to grey over, about fifteen minutes in the chimney, longer if it needs it.
  7. Tip the lit coals into the konro and bank them under one half, leaving the other half empty as a cool zone.
  8. Cook. Move anything that flares to the empty side rather than blowing on it.
  9. When you finish, lift the coals one at a time with tongs into a hikeshi-tsubo and put the lid on.
  10. Leave the lid shut until the charcoal is fully out, then store it dry and relight it next time.

Sources: https://en.wikipedia.org/wiki/Binch%C5%8Dtan · https://www.city.kochi.kochi.jp/site/tosa-kogei/tosanotezukuri-tosabinnchotan.html · https://www.bincho.jp/topics/01topics_03.html · https://somabito.com/view/page/okoshi · https://binchotanogatan.com/binchotan-hiokoshi/ · https://totalfoods.jp/blog/%E5%82%99%E9%95%B7%E7%82%AD/explosion/ · https://www.kinka.co.jp/ · https://www.bepal.net/archives/406451 · http://tokonameenkel.com/2018/09/11/sitirin-2/ · https://ja.wikipedia.org/wiki/%E7%8F%AA%E8%97%BB%E5%9C%9F · https://www.city.suzu.lg.jp/site/kankou/1570.html · https://www.health.nsw.gov.au/environment/Pages/copoisoning.aspx · https://www.health.nsw.gov.au/news/Pages/20230619_00.aspx · https://www.nsw.gov.au/housing-and-construction/strata/living/by-laws

Quick answers

How long does binchotan take to light?
Roughly ten minutes in a chimney starter before it starts to catch, about fifteen before it's glowing. From embers, allow a full hour before cooking.
Can I use a konro indoors?
No. NSW Health says outdoor cooking devices must never be used inside; burning fuel makes carbon monoxide even with no visible smoke.
Why is my binchotan popping and throwing sparks?
Popping binchotan is damp charcoal: trapped moisture flashes to steam and splits it, so store it dry and bring it up to heat slowly.
Can I put charcoal out with water?
Put charcoal out by moving it into a lidded hikeshi-tsubo, never by pouring water on coals still sitting in the grill.
How do I clean a diatomite konro?
A diatomite konro isn't washed; the material is very weak to water, so the ash gets knocked out cold instead.
Am I allowed a charcoal grill on my apartment balcony?
It depends on the building; strata by-laws vary from scheme to scheme, so ask your strata committee secretary or manager for your own scheme's by-laws.