Bushcraft Uses of King Alfred’s Cakes (Daldinia concentrica)

If you spend time exploring British woodlands, you may have noticed hard, black lumps attached to dead branches or fallen logs. They can look like pieces of burnt charcoal or small lumps of coal, but they may actually be King Alfred’s Cakes, a distinctive fungus with a long association with traditional fire lighting.

Known scientifically as Daldinia concentrica, this fungus is also called coal fungus, carbon fungus and cramp balls. It is particularly interesting to bushcraft enthusiasts because its dry interior can catch a spark and smoulder slowly, making it useful for transferring an ember to other tinder.

However, fire lighting is not its only point of interest. Learning to recognise King Alfred’s Cakes can improve your woodland identification skills, introduce you to the relationship between fungi and deadwood, and help you understand how people historically made use of natural materials.

In this guide, we will explore how to identify King Alfred’s Cakes, how they can be used for traditional fire lighting, and why responsible collection matters.

Identifying King Alfred’s Cakes

Before attempting to use any wild fungus, you need to know what you are looking at. King Alfred’s Cakes are distinctive once you become familiar with their appearance, but other dark fungi also grow on dead and decaying wood.

Key identification features

Shape: The fruiting bodies are rounded or cushion-shaped, often resembling small lumps of coal attached directly to wood.

Size: Individual specimens commonly measure a few centimetres across, although larger examples can occur.

Colour: Younger specimens are often reddish-brown or dark brown. As they mature, they usually become hard, dark and almost black, sometimes with a shiny surface.

Texture: Mature specimens are firm and woody rather than soft and fleshy. Their outer surfaces may develop cracks.

Interior: Cutting a specimen through its centre can reveal distinctive concentric layers of dark and greyish material. These rings are an important identification feature.

Habitat: In the UK, King Alfred’s Cakes are commonly found on dead or decaying broadleaf wood, particularly ash and beech. They may grow on standing dead branches, fallen branches and other deadwood.

They can remain visible for a long time, so a fungus you encounter during a walk may have been present through several seasons.

Where to look

Search visually along fallen broadleaf branches and decaying wood in deciduous woodland. Ash and beech are particularly useful trees to examine, although the presence of a fungus should always be confirmed rather than assumed from the host tree alone.

You do not need to remove branches or break apart logs to search for them. Inspecting deadwood in place is often enough to spot their characteristic dark, rounded forms.

For further identification guidance, compare your observations with reliable references such as the Woodland Trust’s King Alfred’s Cakes guide.

Important: Several fungi produce dark growths on deadwood. Do not rely on colour alone. If you are uncertain about identification, leave the fungus where it is.

1. Using King Alfred’s Cakes as Natural Tinder

The best-known bushcraft use of King Alfred’s Cakes is their ability to catch and retain an ember.

When the fruiting body is thoroughly dry, its inner material can catch a suitable spark. Rather than immediately producing a large flame, it can begin to glow and smoulder.

This behaviour makes it useful for understanding the difference between catching a spark and producing a sustained flame.

Why does it work?

The mature fungus has a hard, carbon-rich internal structure that can support slow smouldering under suitable conditions. Once an ember develops, it may continue glowing for an extended period if enough oxygen is available.

This is particularly useful when practising traditional fire-lighting methods, where the first challenge is often producing an ember rather than an open flame.

King Alfred’s Cakes have a documented history of use as natural firelighting material. Archaeological evidence discussed by the Royal Botanic Gardens, Kew, suggests that related traditional uses of tinder fungi extend back thousands of years.

Choosing a suitable specimen

For fire lighting, the internal condition of the fungus matters more than simply finding a black exterior.

A specimen that is damp, soft or deteriorating may not perform well. A mature, thoroughly dry fruiting body is more suitable for experimentation.

Do not assume that every black specimen is ready to use. Moisture and condition can vary considerably.

If you are learning the technique for the first time, practise in a safe, permitted location with suitable fire precautions rather than relying on a wild-collected fungus during an emergency.

2. Transferring an Ember to a Tinder Bundle

King Alfred’s Cakes are especially interesting because the smouldering material can be used as an intermediate stage in the fire-lighting process.

A conventional fire-lighting sequence involves producing an ignition source, catching it in suitable tinder and then developing a flame large enough to ignite kindling.

With King Alfred’s Cakes, the fungus can help bridge the gap between a spark and a flame.

Understanding the process

The general principle is straightforward:

1. A suitable ignition method produces a spark.
2. The dry fungus catches the spark and develops a glowing ember.
3. The ember is transferred to a prepared bundle of suitable, dry tinder.
4. Gentle airflow helps the tinder develop a flame.
5. The flame is used to ignite progressively larger material.

The fungus is not a replacement for a well-prepared tinder bundle. It is part of a wider process, and the surrounding materials still need to be suitable and dry enough to catch the ember.

Fine, fibrous tinder can be useful because it allows heat to spread through the material. Poorly prepared tinder may fail even when the fungus itself has caught a spark.

Why practise this skill?

Working with a smouldering material teaches you patience and control. You learn to recognise the difference between a spark that has disappeared and an ember that is continuing to glow.

It also demonstrates why preparation matters. If your kindling and tinder are not ready before you begin, you may lose the ember while trying to prepare them.

Always keep the glowing fungus over a fire-safe surface and away from dry vegetation, clothing and other combustible materials. A smouldering ember can ignite material even when no open flame is visible.

3. Traditional Fire Carrying

One of the most fascinating aspects of King Alfred’s Cakes is their potential role in transporting fire.

Before modern lighters and matches, keeping a fire going or carrying an ember between locations could save considerable effort. A material that smoulders slowly offers a way of retaining an ember for longer than ordinary fine tinder might.

King Alfred’s Cakes have been associated with this traditional use because a suitably prepared specimen can continue smouldering after ignition.

However, this should not be interpreted as permission to carry a live ember casually through woodland. A smouldering fungus remains a fire hazard, and an ember can escape or ignite surrounding material.

For modern bushcraft practice, it is better to study the principle and demonstrate it only under controlled conditions with appropriate fire precautions.

If you are travelling outdoors, carry a suitable modern ignition source and follow local fire restrictions rather than relying on a live ember.

4. Learning About Natural Fire Materials

King Alfred’s Cakes provide an excellent example of how different natural materials behave when exposed to heat.

Not all tinder works in the same way. Some materials ignite quickly and burn away in seconds, while others may catch a spark and continue smouldering.

Understanding these differences helps you choose appropriate materials for different ignition methods.

Compare tinder types

You can compare King Alfred’s Cakes with other materials discussed in bushcraft, such as:

• Charred cotton cloth prepared specifically for fire lighting.
• Fine, dry plant fibres.
• Suitable dry grasses.
• Dry, finely prepared wood shavings.
• Other naturally occurring tinder materials, where identification and responsible collection are appropriate.

These materials have different strengths and limitations. A material that works well with one ignition method may be difficult to light with another.

The condition of the material matters just as much as its identity. Moisture, preparation, particle size and airflow can all influence the result.

This makes King Alfred’s Cakes useful as a learning resource even if you rarely use them in practice.

5. Understanding the Relationship Between Fungi and Deadwood

King Alfred’s Cakes are more than a firelighting resource. They are part of the woodland ecosystem.

The fungus grows on dead and decaying wood, helping break down woody material as part of the natural decomposition process.

Deadwood is important in healthy woodland because it provides habitat and food for many organisms. Fungi, insects and other wildlife depend on dead branches, fallen logs and decaying tree material.

King Alfred’s Cakes can also provide shelter or habitat for small invertebrates, and certain insects are associated with the fungus.

What this means for bushcraft

A woodland may appear to contain an abundance of spare materials, but deadwood is not necessarily waste.

Removing branches, logs or fungi can disturb habitats and reduce the resources available to wildlife. Even a small item may be part of a much larger ecological relationship.

Learning to recognise King Alfred’s Cakes without removing them is therefore a worthwhile bushcraft skill in its own right.

When you find a specimen, take time to observe its location, the condition of the wood and any other signs of life nearby.

This develops the habit of understanding the environment before deciding whether to use something from it.

6. Responsible Collection and Conservation

Although King Alfred’s Cakes are widespread in the UK, that does not mean every specimen should be collected.

The fungus can remain attached to deadwood for a long time, and the surrounding material may support wildlife. In addition, collecting rules depend on land ownership, permission and any applicable site restrictions.

Before removing anything, establish that you are allowed to do so.

Follow these principles

Leave most specimens in place. There is little need to collect every fungus you encounter. Observing and photographing them can provide the same identification experience without disturbing the habitat.

Avoid damaging the host wood. Do not break apart standing dead branches or tear up logs to reach a fungus.

Check permissions. Do not assume that access to a woodland gives you permission to collect fungi or other natural materials.

Respect protected sites. Follow any local conservation rules and restrictions. Where collection is prohibited or uncertain, leave the fungus untouched.

Avoid unnecessary harvesting. If you have permission to collect a specimen for a genuine learning purpose, take only what you need and leave the surrounding deadwood undisturbed.

The goal of bushcraft should be to develop practical skills while minimising harm to the environment.

7. Can King Alfred’s Cakes Be Eaten?

No. King Alfred’s Cakes are considered inedible and should not be collected for food.

Their value in bushcraft lies primarily in their traditional fire-lighting use and their interest as a woodland fungus.

Never assume that a fungus is edible because it looks familiar or because it has a traditional use. Fungi require careful identification, and some species can be harmful if eaten.

If you are interested in wild fungi, keep identification and food-foraging activities separate. Use reliable specialist guidance and never consume a wild fungus unless you can confidently identify it as an appropriate edible species.

8. Are King Alfred’s Cakes Useful for Warmth?

You may come across claims that King Alfred’s Cakes can be used as small hand warmers because a smouldering specimen produces heat.

Although a glowing fungus can release heat, this is not a sensible technique to rely on for keeping your hands warm. It creates a burn and fire risk, particularly when carried close to skin or clothing.

For outdoor warmth, use suitable insulating gloves, dry layers, shelter and other appropriate equipment.

If you are cold outdoors, prioritise protecting yourself from wind and moisture, adding insulation and moving to a safer location where necessary. Do not place a smouldering fungus in your pockets, gloves or clothing.

This is an example of an important bushcraft distinction: a material may have an interesting physical property without being a safe or practical tool for every suggested use.

9. A Simple King Alfred’s Cakes Observation Exercise

You can learn about this fungus without collecting it or lighting a fire.

During a woodland walk where access is permitted, look for dark, rounded growths on dead or decaying broadleaf wood.

Work through the following exercise:

1. Observe the shape, size and colour of the fungus.
2. Record the type of tree or wood on which it appears to be growing, if you can identify it.
3. Compare the specimen with a reliable identification guide.
4. Note whether it appears young and brown or mature and black.
5. Consider how its presence relates to deadwood and woodland wildlife.
6. Research its traditional use as tinder and explain why a smouldering material can be useful for fire lighting.

Do not cut into a specimen simply to reveal the concentric rings unless you have a legitimate reason and permission to do so. Photographs and observation are often enough for an introductory exercise.

If you later practise its fire-lighting use, do so under controlled conditions, with permission and appropriate precautions.

Final Thoughts

King Alfred’s Cakes are one of the more interesting fungi to learn about as part of your bushcraft education. Their hard, dark fruiting bodies are distinctive, and their ability to catch a spark and smoulder makes them a useful example of traditional natural tinder.

They also demonstrate that bushcraft is about more than collecting resources. Understanding a material, recognising its limitations and respecting the habitat in which it grows are equally important skills.

The next time you spot what looks like a lump of coal on a fallen branch, take a closer look. You may have found King Alfred’s Cakes—a small but fascinating part of the woodland environment.

Learn to identify it, understand its traditional use and leave the woodland in good condition for the wildlife and people that come after you.