Can You Reuse Charcoal? The Ultimate Guide

Have you ever grilled with charcoal and noticed there were still some coals that hadn’t been completely burned down after you finished? And did you just throw them away as most do? Well, that was probably a mistake.

Charcoal left over from your previous grilling or smoking sessions can still be used if it hasn’t burned out completely. Reusing charcoal is not only an economical choice but also a great way to reduce waste.

So next time you fire up a barbecue, consider holding onto those remaining coals so you can have another round of grilling without having to buy more fuel! Want to learn more? Then keep reading.

Table of Contents

How To Reuse Charcoal

When it comes to reusing charcoal, there are a few things you need to keep in mind.

The most important thing is to make sure that your charcoal hasn’t burned out completely. If it has, then there’s no use in trying to reuse it because all you are left with is ash. You can also add some of the ash and smaller pieces of charcoal to your compost pile or you can repurpose it for use in other ways, such as a plant fertilizer, so don’t just throw it away either. 

If left unchecked, charcoal burning in your grill will most likely burn out almost completely, so take the necessary steps to prevent that.

Once you’re done grilling for the day and there are still coals left over, put the lid on your grill and make sure it’s shut tight. Furthermore, you will need to cut off the airflow by closing all the air vents on your grill. By doing this, you will reduce the amount of oxygen that can enter the grill, which will stop the burning process. No oxygen, no burning.

Keep in mind the coals will remain hot for quite a while, so you will have to wait for about 24 hours before even thinking about packing them away.

You can check whether the coals are still hot by holding your hand over them. If you don’t feel any warmth rising, then they might be ready for storage. To be 100% sure, you can leave them alone for 48 hours. Alternatively, you can also use an infrared thermometer to measure their temperature. Either way, storing the unburned charcoal in a fireproof container is generally a good idea.

Make sure to store only the bigger chunks, as storing coals the size of a penny won’t do you any good.

Can You Use Water to Extinguish the Charcoal?

Dumping a bucket of water into your grill might sound like the quickest and easiest way to put out the charcoal, but it’s actually not the brightest of ideas.

If you pour cold water into a charcoal grill full of coals that provided heat of about 500°F just minutes ago, you are risking damaging the grill. You see, metals are not keen on sudden temperature changes, so adding cold water into a hot environment can result in metal warping or even cracking.

I am sure you don’t want your 1,000-dollar Weber grill to break down on you, so ditch that idea.

If you absolutely need to put out the charcoal quickly, you can use metal tongs to pick out the chunks and dump them into a metal bucket filled with cold water. This will douse the coals and won’t harm the grill itself. Be careful and don’t drop the burning coals somewhere where they could start a fire, such as on your covered porch.

The downside of this method is that you are left with chunks of wet charcoal that you can’t reuse any time soon. Will the wet charcoal be usable again? Sure, but it may take a couple of days for it to dry out.

How Do You Light Old Charcoal?

So you’ve collected the charcoal and stored them correctly and now is the time for another grilling party. The process of lighting old reused charcoal is almost the same as when using new charcoal.

The best way to light up the leftover charcoal is by using a charcoal chimney starter. If you don’t have one, get one. It is seriously the best charcoal grill accessory you can get.

To light the coals:

  1. Scrunch up a couple of newspaper sheets and place them at the bottom of the chimney starter.
  2. Next, put the charcoal inside the chimney starter. Unless you have saved used charcoal from several grilling events, you will most likely need to add some new charcoal as well. It works best when you add the coals in layers. New coals – old coals – new coals.
  3. Now light up the newspaper sheets. You can also use lighter cubes instead of newspaper.
  4. It will take a couple of minutes for the charcoal to heat up enough.
  5. Once that happens, pour the coals into your grill and spread them out.

You can now start to cook that steak or whatever it is you are craving.

Are There Any Downsides to Reusing Charcoal?

Yes, there are some downsides when it comes to trying to use the same coals twice.

Most importantly, the reused charcoal pieces will not burn as efficiently as new charcoal, as some of the carbon content has been depleted. This results in lower heat production and it’s the reason why it’s best to mix new and old coals.

Secondly, the old coals might be contaminated. “Contaminated with what?”, you may be asking. Well, mostly with the food that you were cooking. As the food is grilled a lot of juices and fat drips down through the grates onto the hot coals. I am not saying this is a dangerous contamination or anything, it’s just something to keep in mind because it may slightly affect the food you are cooking next.

Can You Reuse Charcoal Briquettes?

Charcoal briquettes are a bit different than classic lump charcoal when it comes to reusing.

You can certainly reuse the briquettes if anything of them survived the grilling session. The thing is, they contain fillers and often also lighter fluid. Due to those ingredients, briquettes will often either burn out or fall apart quite easily.

Also, you certainly don’t want to dump the burning briquettes into the water, as this may again cause them to fall apart. A bucket full of black water is all you could end up with.

Does that mean that trying to reuse briquettes is pointless? Not really. It’s just that you are likely to end up with less usable fuel than if you were to use lump charcoal.

Can You Reuse Charcoal Ashes?

Although you cannot use the leftover ashes for another cookout because there is nothing left to burn, you can use them for other purposes.

  • Soil amendment – As long as no additives such as lighter fluids are present, you can safely use charcoal ashes in your garden. They add alkalinity to the soil and help it to retain moisture more efficiently. Obviously, do add them if your soil is alkaline already, and even if it’s not only them sparingly to not overdo it.
  • Pest control – Sprinkling ashes around plants can help deter pests such as slugs and snails. The sharp edges of the ash particles can irritate their soft bodies, making it difficult for them to move around the area. It’s not a foolproof pest control method but it may help some. However, don’t use this method around plants that prefer acidic soils as the ash will raise the pH.
  • De-icing – The particles can provide traction on icy surfaces, making it easier to walk or drive on the ice. The black or dark grey ash can also absorb heat from the sun, helping to melt the ice more quickly.

As mentioned in the first point, ensure that you’re only using ashes from natural charcoal and non-treated ones.

Final Thoughts

Reusing charcoal is totally doable and can be a great way to save some money. As long as you are saving only the bigger chunks and storing them correctly, they should be usable for another grilling session.

However, you will likely need to mix in some new coals with the leftover ones since they won’t burn as efficiently anymore. Furthermore, don’t forget to double-check for any food contamination before you start your next grilling adventure. Especially if you cooked something funky.

I hope this article helped you.

FAQ

How much ash will the reused charcoal produce?

It will produce about the same amount of ash as new charcoal of the same size.

Is there a limit to how many times I can reuse the charcoal?

It will likely burn out completely during the second use so there is no point in trying to use it for a third time. But you will of course be able to collect some new partially burned pieces if you mixed the old with some fresh charcoal.

Photo of author

John Carder

John Carder is the founder of FreshAirChef.com. He loves to cook outdoors, especially over a campfire. John has a lovely wife and two cats who he loves dearly. In his spare time, he likes to play soccer and paint; he's not particularly good at either, but he enjoys the process nonetheless. He also has silly long hair which often gets in his way while cooking!