Charcoal is an awesome fuel to heat your grill, with reliable heat and low smoke emissions. If you’ve ever wondered if it’s possible to make your own, you’re in luck! In this in-depth guide, we explain everything you need to know, including how to make it at home.
How charcoal is made
At a basic level, charcoal is produced by burning wood or other organic matter at low oxygen levels. Doing so removes water and other volatile substances, allowing the finished product to burn at high temperatures with very little smoke.
This can be done in a number of ways:
- Traditional: pit kilns are used to produce low quality charcoal.
- Technological advanced: using industrial equipment used to produce high quality charcoal with a stable carbon content of more than 82%.
Whether you use low-tech, low-scale method, or high-tech supra-carbonization technology, the basic process is the same. However, the quality of finished coal and the time it takes to create it is very different.
Types of wood and materials used
Charcoal can be made of any type of wood, and other organic matter, such as:
- Coconut shells
- ground nut shells
- dry leaves
Lump charcoal should be made of real wood (usually hardwood).
Hard woods, such as hickory, oak, and beech, tend to burn hotter. So, if you are looking for lump coals, you may want to look out for varieties made of these types of wood.
Sawdust and fine organic matter can be used to create charcoal dust. Briquettes are more likely to contain a variety of woods and are often produced from cutting down logs, including the bark of both hard and soft woods.
Briquettes vs coal lumps
Both lump charcoal and briquettes are often referred to simply as charcoal”. However, there is an important difference.
- Composed of hardwood pieces – This is important to remember, as some charcoal pieces may be from offcuts, so always make sure your wood comes from a reputable company.
- Irregular shape – While there is no problem on its own, it can make controlling your airflow and stacking more difficult than using briquettes.
- Short-term burn time – smaller lumps burns quickly.
- It can burn slightly evenly – Due to its size and irregular shapes, some lumps may not be completely carbonized in the center. This could mean that they emit smoke or sparks from time to time.
- No Additives – Unless otherwise stated, your charcoal burner should not contain any additional additives, unlike most briquettes.
- Regular formed shapes – This makes it easier to stack, so controlling your air flow is easier for a better burn.
- Contains wood products – Usually made from a combination of coal dust, sawdust, and wood chips; briquettes are a mixture of natural combustible substances.
- Additives – In the case of charcoal briquettes, they can be combined with binding additives, which improve ignition and help ensure consistent combustion.
How is charcoal made first?
People have been making charcoal since about 4,000BC. In ancient times, wood was piled up in small quantities, set on fire and then covered with dirt to ensure long, slow-burn with very little oxygen.
As societies change and evolve, charcoal plays a more visible role – used for writing and painting, as well as for smelting metals, to create glass and as an integral part of early gunpowder.
For all these reasons, charcoal production is very important throughout history. Since all the villages were in need of charcoal, charcoal burner formed charcoal at the local level, gradually improving their production methods.
Stacks of charcoal were stored in earth mound kilns, and coal burners often housed small, rudimentary dwellings next to their heapiles, known as charcoal huts.
Earth mound kilns were more efficient than basic kilns when coal was burned below ground level. However, as the carbon production process is very long, requiring continuous attention for more than ten days or more, kilns and charcoal production are later developed with the installation of improved air control chimneys.
In the years that followed, brick kilns were made, followed by steel kilns, which allowed even the lowest wood to absorb carbon. Nowadays, charcoal is produced as an industrial process using vertical cylindrical furnaces.
The wood carbonizes at about 1,470 degrees Fahrenheit, with all the gases produced and destroyed by fire so as not to pollute the air or soil. This is known as the MAGE supra-carbonization process.
What exactly is in charcoal?
Unless you choose pure hardwood lump charcoal or 100% hardwood briquettes, there is a good chance that your charcoal will contain certain additives. This is added to improve thermal performance, and in the case of briquettes, such as binding agents.
Here’s what would be in charcoal;
- Heat fuel materials – This is what makes up your charcoal which is made of wood but can also be made with a combination of materials that include natural biomass. These can include nut shells, coconut shells, peat, paper and tree bark.
- Binding Agents – When using briquettes, binders are required to provide their forms. Common binding agents used in charcoal briquette include starch, molasses and sodium silicate.
- Borax – Borax or sodium borate can be added to charcoal briquettes to make it easier to remove the mold without breaking.
- Sodium nitrate: charcoals may also contain sodium nitrate to improve burning.
How to make your own coal
It can be time consuming and dirty, but making it is a very easy process. If you want to know how charcoal is made, here’s how:
Before you start, make sure you have the following:
- A good supply of hard wood cut into pieces (soft wood burns for a short time making it difficult to make, especially if it is made on a small scale.
- A metal barrel with a lid.
- kindling – small branches or paper to start a fire.
- Heat protection and fire – gloves, metal poker and bucket of water.
- Start your fire at the bottom of your barrel with your kindling and a small piece of wood. Get your fire going strong before you start adding your hardwoods. You will want to make sure you have good flames and plenty of heat.
- When your fire is going, add your hard wood a few layers at a time. Doing so will speed up the process, as the fire will spread from one layer to another very quickly.
- Finish placing your hard wood on top of your barrel and allow the flames to burn all the layers. Wait until you see the wood begin to darken before moving on to the next steps.
- Once you see that all your hardwoods are starting to burn and darken, it is time to put a metal lid on the barrel to limit oxygen supply.
- Let your wood smolder in the barrel for about 24 hours or more, if necessary.
- Remove the lid and check that your wood has finished smoldering. If it is not ready, cover it again and leave it for several hours.
- Be sure your wood is definitely burnt and completely out before removing it from the barrel. If you do not need to use your barrel for another load, you can leave it stored with a lid to protect it from moisture.
How long does charcoal making last?
That all depends on which grill you use, your airflow, and general fire management. Typically, coal briquettes will last anywhere from eight to ten hours, with small coals closing the burn time of about four to six hours.
If you are wondering if charcoal has an expiration date, the answer is no. You can store charcoal permanently.
However, be aware that over time any additives or chemicals that your charcoal may contain may start to wear off, making it difficult to light.
Why is there so much dust left after burning coal?
As coal burns, it cracks. Because of its brittle nature and the complete removal of water from the wood during its creation, once it has burned, you will be left with a lot of black dust.
If you have a lot of dust built up on your grill, be sure to make sure it doesn’t block your airflow between your lumps. The remaining dust has its uses. You can use it to make briquettes. You can spread dust over the soil in your garden to help your plants grow.
Can you use charcoal that is wet?
If you buy low-quality coal, then the chances are that it will collapse and reduce to powder once it is dry. However, high-grade coal may be used after it is wet, if it is completely dry.
Remember that when your coals are wet, you may find that they are not as hot as before. For this reason, you may want to mix it with a new bag or cover it with a long, slow, low grilling.
Therefore, while you can use charcoal, it is best to have a new bag that can provide high temperature, high flame grilling.
Is charcoal bad for the environment?
When it comes to carbon emissions, the carbon footprint of charcoal is almost three times higher than LPG grilling.
While this is by no means environmentally friendly, many forms of cooking are bad for the environment in some way. The good thing about charcoal is that it comes from a renewable energy source, trees, unlike non-renewable sources, such as gas.
So, there you have it – our ultimate guide to how charcoal is made.