How to Choose the Best Charcoal for a Charcoal Oven

Charcoal has a big effect on how well you cook. Good charcoal lights easily, reaches temperature quickly and provides steady, clean heat. Poor charcoal can smell unpleasant, burn too quickly and leave a surprising amount of ash behind.

Choosing charcoal should not be complicated, but the words on the bag are not always helpful. “Premium”, “hardwood” and “restaurant grade” do not guarantee that it has been made well or will perform consistently.

This guide explains how to recognise good charcoal, how different types behave and how much you need in a Charlie Oven. It also explains why we recommend locally-sourced charcoal made from responsibly managed woodland and why good fuel is usually worth paying a little more for.

What is the best charcoal for a Charlie Oven?

For most cooking in a Charlie Oven, we recommend good-quality locally-sourced lumpwood charcoal made from responsibly managed woodland.

It should be dry, smell clean, and contain a useful mixture of solid pieces, with very little dust at the bottom of the bag.

Charcoal made from ash wood is an excellent all-round choice. It lights readily, produces strong, clean heat, and works well for grilling, roasting, baking, and longer cooks.

For long, slow cooking, pure compressed wood charcoal is also an excellent option. Its consistent shape and density help it provide a steady, lasting fire. Check that it is made entirely from wood charcoal, without chemical binders or fillers.

Good-quality charcoal can be cooked over as soon as it is hot. You do not need to wait for it to turn white, and there should be no unpleasant smoke or smell that needs to burn away first.

What is charcoal, and how is it made?

Charcoal is a biofuel made by heating wood with very little oxygen. Instead of burning away completely, the wood is transformed into a light, carbon-rich fuel.

During this process, called carbonisation, water and many of the naturally occurring volatile compounds in the wood are driven off. What remains burns hotter and more cleanly than the original wood.

Charcoal can be made in traditional ring kilns, metal kilns or modern retort systems. You do not need to understand each type of kiln to choose a good bag, but the care taken during production matters.

If carbonisation is incomplete, more volatile material and tar can remain. This can make the charcoal burn with a smoky flame or produce an oily or acrid smell when lit. The Food and Agriculture Organization confirms that charcoal with a high level of volatile material can burn with a smoky flame, while more fully carbonised charcoal burns more cleanly. Read the FAO guidance on charcoal quality.

A bag can therefore contain “100% charcoal” and still be poor quality. Nothing else may have been added, but the wood may not have been fully carbonised. Pure charcoal and well-made charcoal are not necessarily the same thing.

Why does charcoal quality matter?

Good charcoal provides clean, predictable heat. It lights reliably, responds well to airflow and gives you more useful cooking from each bag.

Poor charcoal may:

• Smell oily, chemical or petrol-like
• Produce unwanted smoke
• Burn through more quickly than expected
• Struggle to maintain useful heat
• Break into small pieces and dust
• Leave a large amount of ash
• Perform differently from one bag to the next

Consistent charcoal is particularly useful during a long cook because it makes it easier to judge how much fuel you need and how long it will last. Poor charcoal may burn through sooner, produce excess ash, or need topping up earlier than expected.

Good charcoal usually costs more than the cheapest bags, but price per bag is a poor way to judge value. A cheap bag may contain more dust, provide less cooking time and leave less usable charcoal behind.

What matters is the amount of useful cooking you get from it.

Do you need to wait for charcoal to turn white?

No. You can cook over good-quality charcoal as soon as it is hot.

You do not need to wait for every piece to develop a white coating of ash. Good lumpwood charcoal should not contain fillers or lighting chemicals that need to burn away before cooking.

The white coating is simply ash forming on the outside as the charcoal burns. Waiting for every piece to turn white wastes a lot of the fuel before you have started cooking.

Good charcoal should light cleanly without heavy smoke or an unpleasant smell. If charcoal produces thick smoke or an oily, petrol-like smell, do not cook over it. This suggests that it may have been poorly finished and still contains unwanted tar or volatile compounds.

It does not necessarily mean petrol has been added, but it is not the clean heat we recommend cooking with.

The Charlie rule is simple: once good-quality charcoal is hot, you can cook.

How does charcoal control the temperature in a Charlie Oven?

Charcoal needs oxygen to burn. In a Charlie Oven, the top and bottom vents control how much air reaches the fire and therefore how quickly the charcoal burns.

When lighting Charlie, open both vents fully and close the oven door. This creates a strong flow of air through the oven and helps establish the fire.

Once Charlie reaches the required temperature, set both vents to a gap of about two fingers. This allows a steady trickle of air through the oven and holds the temperature steady.

More oxygen makes the charcoal burn faster and raises the temperature. Restricting the oxygen slows the burn and reduces the heat. Closing both vents cuts off the oxygen and extinguishes the fire. The temperature in the oven will then decrease, albeit very, very slowly.

The amount of charcoal determines how much fuel is available and how long the fire can last. It does not determine the burn rate on its own. Once the fire is established, airflow controls how quickly the fuel burns.

For a long cook, you can put plenty of charcoal in Charlie at the start. It will only burn at the rate allowed by the airflow. If more fuel is needed later, simply add it.

Lumpwood, compressed wood charcoal or briquettes?

Not all compressed charcoal is the same. Its ingredients and method of production matter more than its shape.

Pure compressed wood charcoal may also be described as extruded charcoal, charcoal logs or briquettes. Because the names overlap, read the ingredients rather than relying on the product name.

Good lumpwood is our preferred fuel for most cooking in Charlie because it is natural, responsive and produces strong, clean heat. Pure compressed wood charcoal comes into its own on long cooks because its uniform size and density make the fuel load consistent.

The claim that all lumpwood is good and all briquettes are bad is too simple. Poorly made lumpwood can contain unwanted volatile material, burn quickly and produce a lot of ash. Pure compressed wood charcoal without fillers can be excellent.

What does restaurant-grade charcoal mean?

“Restaurant grade” normally describes larger pieces of lumpwood sold for frequent or high-temperature cooking. It is not a recognised performance standard and does not guarantee quality.

It does not prove that the charcoal:

• Comes from a responsible source
• Has been fully carbonised
• Contains little ash
• Burns for longer
• Has been carefully graded
• Will perform consistently

Very large lumps can be awkward to arrange and may take longer to catch. Small pieces help a fire establish but are used more quickly.

A useful bag contains medium pieces for the main fire, some larger pieces for a longer burn and smaller pieces to help everything catch. It should contain very little dust or debris.

Some restaurant-grade bags have a few enormous pieces on top and a landslide of crumbs beneath them. Judge the whole bag, not the most impressive lump.

Why does some charcoal produce so much ash?

All charcoal produces some ash because wood contains minerals that do not burn.

Ash levels vary according to:

• The species of wood
• The amount of bark used
• Natural mineral content
• Soil or sand entering during production
• The amount of dust and small fragments

The Food and Agriculture Organization identifies wood species, bark and contamination with earth or sand as important causes of varying ash levels. It notes that good lump charcoal commonly contains around 3% ash, although the figure varies. Read the FAO guidance on wood carbonisation.

A large amount of ash does not mean the charcoal produced more heat or burned for longer. Ash is the material that did not burn.

Heavy ash can also restrict airflow around the fire. This matters in a charcoal oven because airflow controls the rate of burning.

There is an important difference between ash charcoal and charcoal ash. Ash charcoal is fuel made from the wood of an ash tree. Charcoal ash is the mineral residue left after the fuel has burned.

Does the size and type of wood matter?

A mixture of charcoal sizes is more useful than a bag filled entirely with enormous pieces.

Smaller pieces help the fire catch but are used more quickly. Medium pieces are easy to arrange and suit most cooking. Larger pieces take longer to catch but can provide a longer burn.

Dense British hardwoods such as oak, beech and hornbeam can produce solid charcoal with steady performance. Charcoal made from ash wood is an excellent all-rounder because it lights readily and produces strong, clean heat.

The species is only one part of the answer. Good wood can still be turned into poor charcoal if it is not carbonised correctly. Production quality, dryness, grading and storage may matter more than the name of the tree printed on the bag.

How much charcoal should you use in a Charlie Oven?

For most grilling, roasting and baking, start with roughly half a football’s worth of good-quality lumpwood charcoal.

This can bring Charlie to at least 250°C and provide useful cooking heat for four to six hours.

Actual performance will depend on:

• The type and quality of charcoal
• The vent settings
• The cooking temperature
• The weather
• How often the door is opened
• The amount and temperature of the food

The quantity of charcoal does not set the temperature on its own. Once the fire is established, airflow determines how quickly it burns.

How much charcoal should you use for low and slow cooking?

For low and slow cooking at around 110 to 130°C, you can load enough fuel for the full cook and control its burn rate through the vents.

Pure compressed wood charcoal is particularly useful for brisket, pork shoulder and other long cooks because it provides a steady, lasting fuel supply.

If the cook runs longer than expected, add more charcoal when needed.

How much charcoal should you use for pizza?

For pizza, use roughly a full football’s worth of good-quality lumpwood charcoal. Position the fire towards the back of the oven and allow Charlie to reach around 375 to 400°C.

The oven may reach the required air temperature before the pizza stones have absorbed enough heat. Allow about 30 minutes for the stones to heat fully.

Where does the barbecue flavour come from?

Good-quality charcoal mainly provides clean heat. It should not make everything cooked in Charlie taste smoky.

The familiar barbecue flavour develops when meat cooks and its fat and juices drip onto the hot charcoal below. They create smoke and aromas that rise back through the oven and meet the food.

When baking bread or pizza in Charlie, there is no meat fat dripping onto the charcoal. You therefore do not get that same barbecue smell or flavour. The charcoal provides the heat, allowing you to bake without making the bread or pizza taste smoky.

If you want to introduce a controlled smoke flavour, add one small chunk of dry smoking wood or a handful of dry wood chips.

What colour should smoke be?

A good charcoal fire should produce very little visible smoke. When you add smoking wood, aim for a thin stream of smoke that may appear faintly blue and can be almost invisible.

Dense white or grey smoke is often described as dirty smoke. It can be caused by damp wood, poor airflow, too much smoking wood or a fire that is not burning cleanly. Leave food in it for too long and it can develop a bitter, acrid or ashy taste.

Dark, sooty smoke is another warning that something is not burning cleanly. Fat or meat juices meeting the fire can produce brief bursts of darker smoke. This is different from the fire continuously producing dirty smoke.

Smoke colour is a useful guide, not a laboratory test. Thin blue smoke can be difficult to see, so use your nose as well. Clean smoke smells light and pleasant. Dirty smoke can catch in your throat and smell bitter or acrid.

More smoke does not automatically mean more flavour. Quite often, it just means bitter food.

Should you soak wood chips?

We recommend using dry wood chips and chunks in Charlie.

Wet wood must heat up and lose its water before it can burn. That delays the point at which the wood begins producing the clean smoke we want.

For clean smoke:

1. Establish the charcoal fire.
2. Set Charlie to the required temperature.
3. Add one small dry wood chunk or a handful of dry chips.
4. Maintain a steady flow of air.
5. Look for thin, faint smoke rather than a thick cloud.
6. Do not keep adding wood simply because the smoke is difficult to see.

Can you reuse charcoal left in a Charlie Oven?

Yes. All unburnt charcoal left in Charlie is reusable.

When cooking is finished, close the top and bottom vents. This removes the oxygen and extinguishes the fire. Moisture does not get into the closed oven, so the remaining charcoal stays dry.

For the next cook:

1. Bring the reusable pieces together on the fire grates.
2. Check how much fuel remains.
3. Add fresh charcoal if required.
4. Light it with a natural wool firelighter.

You do not need to remove the fuel or store it separately. It can remain inside Charlie until the next cook.

Is charcoal a sustainable fuel?

Charcoal is a biofuel because it is derived from biomass. However, being a biofuel does not automatically make every bag sustainable.

Its impact depends on:

• Where the wood came from
• Whether the woodland was responsibly managed
• How efficiently the charcoal was produced
• How far it travelled
• Whether its origin can be traced

Locally sourced charcoal made from responsibly managed woodland can support coppicing, thinning and other useful woodland work.

Forest Research says that woodfuel sourced from well-managed woodland can form part of a renewable carbon cycle. It also cautions that forest bioenergy is not automatically low carbon in every circumstance. Read its guidance on biomass sustainability and forest bioenergy.

We recommend charcoal from specialist local makers and sellers. It offers clearer provenance, supports woodland management and avoids transporting charcoal over unnecessary distances.

Where should you buy charcoal?

If you live in the UK, buy from specialist British charcoal makers and sellers who can explain where the wood came from and how it was produced.

Look for:

• British-made charcoal
• A clearly named producer
• Wood from responsibly managed woodland
• Dry, undamaged packaging
• A useful mixture of solid pieces
• Very little dust
• A clean smell when the bag is opened
• Clear ingredients on compressed products

Avoid imported charcoal with vague provenance, bags that identify only the distributor, damaged packaging and compressed products with unclear ingredients.

Good charcoal should have a clear story. If nobody can tell you where it came from or how it was made, choose another bag.

How should charcoal be stored?

Keep bagged charcoal dry and protected from damp. Seal or fold an opened bag and store it under cover, ideally raised off a concrete or earth floor.

A suitable lidded container will help keep out moisture and protect the pieces from being crushed.

Do not store charcoal beside petrol, solvents, paint or other strong-smelling chemicals. Handle the bag carefully because every drop turns more useful lumpwood into dust.

Charcoal already inside a closed Charlie can remain there until the next cook.

How can you tell if charcoal is good quality?

The packaging tells you what the producer claims. The fire tells you whether the charcoal is any good.

What to remember

Choose locally sourced lumpwood charcoal made from responsibly managed woodland. Charcoal made from ash wood is an excellent all-round choice, while pure compressed wood charcoal is particularly useful for long cooks.

You do not need to wait for good charcoal to turn white. Once it is hot, you can cook.

The amount of charcoal determines how much fuel is available. Airflow determines how quickly it burns.

Use roughly half a football’s worth for most cooking and a full football’s worth for pizza.

Good charcoal mainly provides clean heat. The familiar barbecue flavour develops when meat fat and juices meet the hot charcoal. This is why bread and pizza do not come out tasting smoky.

If you add smoking wood, use it dry and sparingly. No more than you can fit in the palm of your hand. Aim for thin, almost invisible smoke rather than a thick cloud.

Find a well-made charcoal that performs consistently and stick with it. Knowing how your fuel behaves makes every cook easier.