Good charcoal
HOW DO I RECOGNIZE GOOD CHARCOAL? MANUFACTURING, QUALITY CHARACTERISTICS, PURCHASE RECOMMENDATION
Recognizing good charcoal
Everyone knows the feeling: you're in a hardware store, standing in front of a wall of charcoal from various manufacturers, and you don't know which one to buy. Because you think, "they're all pretty similar anyway, black inside, and in the end, they'll just be burned." And usually, you grab whatever is cheapest or most well-known. The latter is usually from Weber or ProFagus. We'll explain here whether that's the best choice.
Charcoal Production – How does it work?
Raw material wood: Before we deal with the end product, let's take a closer look at the original material. What is wood actually made of?
Chemically speaking, wood consists of cellulose, hemicellulose, lignin, extractives, and minerals.
Cellulose and hemicellulose are both polysaccharides (multiple sugars) and are essentially biomass, or the main component of plant cell walls.
Lignin is the "glue" in wood that holds everything together and is responsible for "lignification." In other words, it's what makes wood as hard as it is. At 25-30%, the lignin content in wood is about 10 times higher than in a flower stem.
Extractives are products of plant metabolism and make up only a small part of the wood. The group of extractives includes, among others: carbohydrates, amino acids, fats, isoprenoids, resins, terpenes, but also phenols, tannins, lignans, and flavonoids. If you delve deeper into the individual substances, you will realize what a versatile and wonderful product of nature wood is.
Aspirin, pharmaceutical substances (Taxol from yew for cancer therapy), signaling compounds, fungicides, insecticides, flavorings and fragrances for food (tea, red wine, etc.) can be obtained from wood extractives. But we won't go into detail here; if you want to know more, it's best to check Wikipedia.
Minerals are present in very small amounts. Depending on the location and soil conditions, the tree can contain potassium, calcium, zinc, and manganese. Natural wood also contains small amounts of heavy metals, sulfur, and chlorine. In reclaimed wood, everything from lead, cadmium, chromium to arsenic, nickel, and mercury has been found.
Depending on the wood species and location, the list can vary for each tree.
Looking at the elemental mass particles of dry wood, they are as follows:
50% carbon, 43% oxygen, 6% hydrogen and 1% nitrogen and other elements
To produce good charcoal, the volatile components must be driven out of the wood so that a high content of carbon, or fixed carbon, remains at the end.
Volatile components is the collective term for organic, i.e. carbon-containing, substances that evaporate easily, or are already present as a gas at low temperatures.
This means that part of the carbon contained in wood is outgassed during charcoal production. Therefore, it is misleading to believe that 100kg of wood will yield 50kg of charcoal, because the carbon content in wood is about 50%. This is because gases like oxygen react with carbon during outgassing and escape, e.g. as CO, from the wood. Part of the carbon contained in the wood is thus counted among the volatile components, which are around 75 – 80%. This means that from 100kg of wood, about 10-20kg of charcoal remain. Whether it's 10kg, 15kg or 20kg depends entirely on the skill of the charcoal burner and the kiln used.
The values correspond to very good charcoal and may vary depending on the quality of the charcoal.
Pyrolysis:
To make charcoal from wood, the wood must not burn, but must be heated in the absence of oxygen. So, a space, kettle, oven or similar must be created that can be sealed airtight, so that no air can get in, but smoke or gas can escape. This process is called pyrolysis, or dry distillation, and it begins at about 200 degrees Celsius.
During pyrolysis, solid, liquid, and gaseous substances are formed.
Solid: Charcoal
Liquid: Wood tar (pitch) and wood vinegar (liquid smoke)
Gaseous: Wood gases
When wood gases cool and condense, wood tar and wood vinegar are formed. But wood gases can also be used in other ways, as about half of their components are flammable. These components are carbon monoxide (~34%), methane (~13%), ethylene (~1%), formaldehyde (~1%), methanol (~1%) and hydrogen (~1%). The non-flammable components are carbon dioxide (~49%) and nitrogen (~1%).
Wood gases are either fed into the pyrolysis heating process or diverted and used for other energy generation. Up until the 1950s, there were trucks with wood gas engines. World War II made gasoline difficult for the civilian population to access, as everything was needed for the military. So people became inventive. With a calorific value of 8,500 kj/m3, wood gas from 3 kilograms of wood corresponds to the energy value of 1 liter of gasoline.
MARABU charcoal with a GRILLSTARTER
Time & Temperature:
In summary, one can say that charcoal is produced by the degassing of wood. This is the rudimentary approach. However, it largely depends on the temperatures at which pyrolysis is carried out, how long it lasts, and at what temperature it ends. All of this must naturally be adjusted to the type of wood, the size of the kiln, and the size of the wood pieces, so that a high-quality product is produced at the end of the day.
If you want to produce first-rate quality, like Binchotan, it requires years of experience to know which volatile components escape preferentially at which temperature and for how long this temperature level must be maintained so that the corresponding gas has completely escaped. The final carbonization temperature, usually above 1,200 degrees C, is significantly higher than for "normal" hardware store charcoal. True master charcoal burners even work with different pressures in the kiln and can tell how far the outgassing process has progressed by the color of the smoke and the color of the embers.
Oven:
There are various ways to seal a wood-filled space airtight to produce charcoal. The smallest and simplest form is probably an old, repurposed barrel. Slightly larger are specially built kettles and chambers made of iron or steel.
In the same size range and even larger, there are kilns made of bricks and firebricks. Of course, there are also combinations of bricks, chamotte, and steel.
Ovens made of bricks and firebricks
Modern carbonization plants today are factory-sized and largely operate fully automatically, processing tens of tons at once.
Charcoal Factory
Charcoal Kiln:
One method that requires no stones or iron is that of the classic kiln, where brushwood and a mixture of ash, earth, and mud are placed and applied to the piled-up wood heap, so that the wood underneath no longer receives air. Each method has its pros and cons, which we will briefly discuss below.
Charcoal kiln with brushwood, ash, earth and mud
Barrel:
Converting a barrel into a charcoal kiln can be done relatively quickly with the right tools and a bit of craftsmanship. Theoretically, anyone could do it in their backyard. However, operating it becomes a bit tricky, as you need a permit for that in Germany. With a bit of paperwork, you can certainly get one, but it's not particularly effective, as such a bare barrel is very poorly insulated and loses an unnecessary amount of heat.
It can only be reused a limited number of times, as the prevailing temperatures take a toll on the barrel over time. In addition, temperature control is only partially possible, and the filling volume is severely limited. Even if you only want to produce charcoal for your own use and barbecue regularly, you have to fire up the barrel every 2-4 weeks.
Nevertheless, the barrel method is still widely used around the world, especially in very poor areas. However, instead of one barrel, 20 or more barrels are often fired up at once.
Conclusion: a nice gimmick, but very ineffective.
Steel Kettle/Bell:
Kettles specially built for charring are already better in terms of performance. However, the design always matters here too. Just because it's bigger than a barrel doesn't necessarily mean it's better. Only if sufficient attention is paid to insulation, wall thickness, materials used, and the possibility of temperature control can good results be achieved with a kettle.
Kettle for charring
If one of the components is not right, it becomes more difficult, but not impossible. Because then you need even more experience to recognize from the changes in the oven what needs to be done. The selected materials play a major role in how often and how elaborately the kettle needs to be maintained and repaired. At temperatures of 800 degrees Celsius and more, the steel and also the insulation are heavily stressed.
Conclusion: Bigger isn't always better. The design of the oven determines its efficiency and half-life, as well as, together with the charcoal burner's experience, the quality of the charcoal.
Stone Oven:
Depending on the thickness of the walls, one could say that stone ovens consist only of insulation. This is definitely a huge plus for such ovens. They can be operated at very high temperatures and last a very long time. They are not entirely maintenance-free, but much less prone to wear than their steel counterparts. In comparison, they are also easier to build, although experience is also needed here to know how to stack the stones to insulate well and last a long time.
Round charcoal stone oven
It comes in different sizes, shapes, and variants. And examples of it can be found all over the world. Typically, they are built round for stability and have an average diameter of about 3-5 meters. However, there are also rectangular brick ovens. The height varies between 3 and 6 meters.
A disadvantage is that the escaping gases are usually not captured and reused. Furthermore, such coal kilns are mostly heated with an open fire, which makes temperature control more difficult. However, it is not impossible, as the charcoal burner then manipulates the air supplied to or removed from the fire.
Rectangular charcoal stone oven for Binchotan charcoal
All Binchotan kilns are made of stone because the wear and tear on the material is lower due to the high temperatures during Binchotan production. Steel kilns would not have a long lifespan.
Conclusion: Long lifespan, as it is not susceptible to rust, good insulation. With poor construction, or after prolonged use, cracks can occur, through which external air is drawn in, leading to a poorer quality of charcoal. Depending on the construction method, by-products such as wood gas, wood vinegar, or wood tar can be more easily skimmed off and recovered. A good oven with proper construction.
Traditional charcoal kiln
Charcoal Kiln:
Traditional charcoal kilns, also called mound kilns, are rather rare today. Especially in Central and Western Europe, they are only found very sporadically. The knowledge of charcoal production was usually passed on to descendants.
However, since the profession is rather dirty, physically strenuous, and not as glamorous as "something-with-media," and the yield from charring cannot keep up with rising living costs, the craft is slowly dying out. Sporadically, kilns still smoke in Germany. But this is usually only for hobby purposes or as a sideline for a farmer.
In the classic production of charcoal, logs are stacked according to a specific pattern to form a conical tower. Typically, this is 3 meters high and 8-10 meters in diameter. Then the tower is covered with brushwood branches, followed by a layer of earth, ash, and CXCX to seal the tower airtight. After that, a fire is ignited at the top in the middle or at the bottom through a free channel in the center of the tower to initiate pyrolysis. Then the hole is sealed with more logs.
Now, small holes are gradually poked into the layer of earth around the kiln so that the wood gases can escape. Based on the color of the smoke, the charcoal burner can see when he needs to close the holes again and open them elsewhere.
Depending on the size of the kiln, this process takes 1-3 weeks.
Pit kiln
Instead of building upwards, one can also dig deep and then seal it airtight; this is called a pit kiln. The principle is the same, only the quality is not as good as with a mound kiln.
Conclusion: The biggest advantage is that the kiln can be built where the wood is, and the wood does not have to be brought to the kiln. Anyone who knows what they are doing can certainly produce excellent charcoal with this method, but the quality still varies between the charcoal inside, in the middle, and on the outside of the kiln. Another disadvantage is that it is very labor-intensive and there is no way to separately remove and recover wood vinegar or wood tar. Just an old method.
Rotary kiln charcoal:
When you hear that something is "from the retort," you generally think of something that is not special or even of inferior quality. Many understand "retort" to mean "from the factory" or "off the shelf." This is essentially true, as the word retort means "sealed vessel," is used in the distillation of liquids, and has been used in this way since the Middle Ages.
Since charcoal production is also referred to as dry distillation, the term has been adopted here.
Production of retort charcoal
When retort charcoal is mentioned, it refers to something good, because with retort charcoal, the conditions are always the same, thus always yielding the same quality. This means that if you buy a bag of retort charcoal of a certain brand, you can assume that the quality of the same brand a year later will be exactly the same. This is interesting for all those who barbecue often and want to rely on the charcoal always being consistently good.
Binchotan charcoal
Retort charcoal refers to all charcoals that have been produced in a double-walled steel vessel, where heat is supplied from the outside and not generated directly by fire in the same chamber as the charcoal.
Sieving:
No matter how the wood became charcoal, it is usually sieved and bagged afterwards. At least, that's what good manufacturers do. If you choose to buy as cheaply as possible, you shouldn't be surprised if 10-30% dust and small pieces unsuitable for grilling are at the bottom of the bag.
Binchotan charcoal
History of Charcoal:
Charcoal, or charcoal tar, was already used in the Mesolithic Age (approx. 9,000 BC). At least, birch pitch in the form of glue from this period has been found.
At the latest since the Iron Age (approx. 800 BC), charcoal has become indispensable. To extract iron from iron ore, high temperatures are required that cannot be achieved with wood. The production of steel also required immense amounts of charcoal to meet the ever-growing demand. Charcoal was then the most modern form of mobile energy. It has an enormously high calorific value (~32MJ/kg) compared to wood and also weighs significantly less to produce the same amount of energy.
Use of charcoal as a heat source
Charcoal was used wherever intense heat was desired, but no smoke or flames.
This continued for nearly two thousand years until the mid-19th century, when coal replaced charcoal with the spread of railways.
Today, charcoal is primarily used for grilling and is rarely applied in industry.
How to recognize good barbecue charcoal:
Everyone knows what charcoal looks like. It's just that black stuff you use to grill. But how do I distinguish good charcoal from bad? How do I know if expensive charcoal is really good?
BINCHOTAN charcoal
One method is to light and test it, but then, in the worst case, I've already bought a pig in a poke and regret wasted money.
The simplest and most reliable trick is the sound. You can even do this test with a sealed bag directly at the dealer. To do this, pick up the bag and shake it so that the charcoal pieces rub against each other. If you hear a sound that tends towards glassy, metallic, and ceramic, the charcoal is likely good, indicating a high carbon content and a solid structure of the charcoal.
MARABU charcoal from Cuba
If the tone is dull, I would stay away from it, unless the charcoal is only meant for lighting other charcoal or briquettes. If the charcoal sounds dull, it still contains many gases that should have been driven out during carbonization. Many gases mean that the charcoal lights easily, but it also means that the charcoal will smolder and smoke and produce large flames when fat drips. So always pay attention to a high-pitched sound from the charcoal.
If you want to know for sure, take the charcoal out of the packaging and look at its color. If the charcoal is still slightly brownish, that's not a good sign. Because then the charcoal is still half wood and poorly carbonized. Dull black means that the charcoal is indeed charcoal, but not of particularly good quality either. If you are looking for good or very good quality, you should look for shiny surfaces and a slightly grayish-silvery color. Very good quality charcoal usually doesn't make your fingers and hands dirty when you touch it.
Quickly getting dirty fingers is an indicator, but not a guaranteed proof of inferior quality. However, if your fingers stay clean, that's confirmation of good charcoal.
If the charcoal breaks easily, even with slight pressure from your fingers, that also indicates poor craftsmanship from the charcoal maker. The charcoal maker was impatient and heated the charcoal too quickly. The result is that you will most likely only find small pieces and fragments in the bag after moving it from shopping to the car, from the car to the garden shed, and from the garden shed to the grill.
But if all these clues and features still don't help determine whether the charcoal is good or not, you actually have to light it and test it live. We'll go into what to look for here a bit further down.
Which types of wood are most commonly used for barbecue charcoal?
Basically, a distinction is made between softwood and hardwood charcoal. In German usage, all conifers are referred to as softwood and deciduous trees as hardwood. Conifers generally grow much faster and therefore have a "lighter," lower density, which also affects their burning behavior.
Which wood makes better charcoal depends on what it will be used for. If I want quick, easily ignitable charcoal, softwoods are more suitable. If you want the longest possible burning time, you should opt for hardwoods. However, you must then accept that lighting will take a few minutes longer.
Regarding quality in terms of smell, smoke, and flame formation, it doesn't matter whether soft or hard wood is used. Here, it only depends on how good the oven or retort is, and above all, how skilled the charcoal maker is.
The most popular and well-known type of wood in Germany is beech, a widespread native hardwood. Charcoal made from beech wood glows for a very long time and beautifully hot, and is usually very low in smoke, making it a popular charcoal among Germans.
Another widespread hardwood is oak. However, it is not nearly as popular as beech among Germans. The reason for this is easily explained. Oak wood has a different composition of volatile components and requires a higher peak temperature to turn the charcoal into good charcoal.
These high temperatures of over 800°C were technically not feasible in the past. This led to oak charcoal not being the best, and this idea became ingrained in the minds of grillers and charcoal users. With today's technical possibilities, excellent quality oak charcoal can be produced, which is in no way inferior to the quality of beech charcoal.
Conifers are generally rarely or never processed into charcoal, as they have a very high resin content and, due to their low density, burn out far too quickly.
Anyone who has read our blog post on the Grill Charcoal Guide knows that the lion's share (85%) of charcoal grilled in Germany today is imported. You can find exact figures and countries of origin in the Grill Charcoal Guide blog. Here we would like to focus on the types of wood used.
Unfortunately, far too much of it still comes from undefinable tropical wood, which was very likely illegally logged. This is partly because the poorest of the poor have little left but to exploit nature to earn money for food and ultimately to live. And partly it is greedy corporations who can't get enough, are blinded by money, and think, "A little bit of forest isn't that bad." Unfortunately, there are too many of these money-blinded people, and as the saying goes, every little bit helps.
And unfortunately, quality seals like FSC or PEFC don't always help there either. In our blog post SUSTAINABLE GRILLING WITH CHARCOAL "MADE IN GERMANY"? you can find out more about this topic.
If you want to buy charcoal with a clear conscience, you should make sure that the type of wood is stated on the packaging or advertised. Well-known and popular varieties include Quebracho Blanco, Acacia & Marabu.
Quebracho Blanco comes from South America (Brazil, Bolivia, Paraguay & Uruguay) and translates to "that which breaks the axe". Here, the name says it all; the wood, with a density of 0.885 g/cm³, is extremely hard and energy-rich, and accordingly yields very hot and long-burning charcoal that does not smoke or spark.
Quebracho Blanco from South America
The reason this wood is not used for furniture is partly because the tree does not grow very tall, but its trunk and branches grow very crooked, which is not ideal for furniture making. And if you do find a beautiful, straight specimen, the wood tends to become brittle and crack when drying. Consequently, locals preferred to process it into very good charcoal, which has now become very popular in Germany. As for reforestation, some charcoal producers have realized that they can only secure their future by planting new young trees.
Acacia wood is as diverse as honey. Acacias grow on all continents with tropical or subtropical climates. There are a total of 1,400 different species, 950 of which occur in Australia alone.
Hook-thorn acacia (Acacia mellifera)
Acacias, often also called mimosas, are mostly not trees but shrubs that are frequently thorny. However, they still belong to the hardwoods.
Especially in countries like Namibia, where in colonial times immigrants mowed down everything to create space for grazing, the thorny acacia bush had plenty of room to spread. The immigrants of that time have disappeared, and with them the cattle herds. Instead, the acacia came and literally bushed up the land, much more than there used to be. Now efforts are being made to free the land from the bush again, and there is a lot of work ahead, as Namibia is large and very bushy.
Acacia charcoal from Namibia
Here too, the raw material cannot be used much; the thorns prick, the branches are too thin and overgrown. One of the best solutions is to make charcoal from it.
Acacia charcoal from Namibia is good, but not among the best. It lights quickly, but that also means it burns out quickly. And because most prefer a long glow, it cannot compete with beech, oak, or Quebracho Blanco. However, for those who only want to grill a few sausages and neck steaks, acacia charcoal is still a good choice.
Marabu, like acacia, is not a tree but a bush. A bush that originally came from West Africa but arrived in Cuba many years ago. Whether intentionally or not, no one knows. However, Cubans know that they are tired of the bush, as marabu proliferates like a weed in Cuba and threatens local agriculture.
The Cubans cannot eradicate the bush, because a small piece of root is enough and it returns. However, the locals also have no real use for the crooked marabu bush, and so it was simply burned for a long time. Until someone realized that the embers were extremely hot and lasted a very long time. Putting two and two together, the Cubans began to produce one of the best charcoals in the world. Even beech charcoal cannot compete with it.
Marabu charcoal is characterized by the fact that the charcoal pieces look like branches, not lumps, and the sound of the charcoal is bright and slightly glassy. We will explain what this is all about in the next section.
Conclusion: When buying charcoal, make sure that the type of wood is specified. Ideally, one of the types mentioned above. If no type is specified, a seal is desirable, but you can no longer rely on that either. If you buy one of the types mentioned in the previous section, you will have good to very good quality, and with a high probability, a clear conscience.
You can play it safe with briquettes made from coconut shells or bamboo. These are only available as briquettes, but they are 100% sustainable in terms of raw materials, as they are made from natural waste. And the quality also speaks for itself. But they are briquettes and not charcoal. If that doesn't bother you, you have a great alternative here.
What are the burning properties of good barbecue charcoal?
Whether a wood charcoal is good depends in part on what I need it for. If I want to grill for as long as possible, then I'd better choose hardwood with large pieces of 120-200mm. If I want to generate embers and get up to temperature as quickly as possible, charcoal made from soft wood with medium-sized pieces of 60-80mm is recommended.
If charcoal is harder to light than you're used to, there can be two reasons. The charcoal is damp and therefore difficult to ignite, or the barbecue charcoal has a higher calorific value and stores more energy per unit. Then it needs more heat and a little more time to "get going". But once it's burning, it pays you back everything in the form of heat and burning time. Bad doesn't mean bad charcoal, the opposite is usually the case.
Grill briquettes specially developed for lighting charcoal, such as our grill starters made from coconut shells, make lighting much easier. Thanks to the integrated lighter, you only need a lighter and can achieve perfect embers in 10 to 15 minutes.
However, in any case, the charcoal should not smoke or even smolder when lit. This is evidence of insufficient carbonization. Bad charcoal stinks, is annoying and can be detrimental to health. It is better to pay one euro more, then grilling is more fun and nothing goes wrong.
Good barbecue charcoal also has no, or only a slight, flame formation, as the volatile components have already been degassed during carbonization.
The amount of ash in good barbecue charcoal is small and the ash color should be as light as possible, then you can be sure that nothing chemical has been added. The heat development is noticeably high and the burning time is correspondingly long.
Binchotan, or white charcoal, is the ultimate in charcoal.
Japanese Yakitori grilled over Binchotan charcoal
Where can I reliably find the best charcoal?
Most charcoal purchases are spontaneous or impulse buys. The weather is or will be good, and everything for a cozy barbecue is quickly bought. Mostly in the supermarket, here you can get food and everything from aluminum foil to toothpicks in one place. But the selection of barbecue charcoal in the supermarket is very limited, usually there is only the private label and that as cheaply as possible. But as described above, cheap is usually the worse choice.
You can be lucky and find good charcoal for little money. But these are absolute exceptions. But if you have found such a source, it is best to buy larger quantities from the same palette, as the batches can vary greatly.
You have a little more choice in the hardware store. Usually 3 or even 4 different varieties. But that is still no guarantee that something good will be among them. But the probability definitely increases.
You're on the safe side in a decent barbecue specialty store, or in a hardware store with a corresponding barbecue department. They know their stuff and wouldn't bother with inferior quality. After all, customers come there specifically to get something better than the widespread standard. They want very good, or the best, quality. And they should get it.
If you still have a few days until the barbecue party, you can also order good barbecue charcoal online.
What are the uses for charcoal?
In addition to grilling, charcoal is also used for many other things. For example, for air and water filters in the form of activated carbon with a surface area of over 800m² per gram.
Charcoal is a wonderful moisture reservoir and thus a cozy home for good bacteria and is used in high-quality potting soil but also in compost. Activated charcoal can also be used to create the nutrient wonder Terra Preta, the best flower fertilizer or growing medium for plants, made from 100% natural ingredients.
Charcoal is a good home remedy for diarrhea. Charcoal is used as a dye, tooth powder, polishing agent and preservative. Charcoal can be used to draw, defusel brandy and make gunpowder. Even in the construction of semiconductors, charcoal is used.
Charcoal has been a part of humanity for many centuries and serves as a source of heat and energy. And in addition to all the possible uses, grilling is certainly the most delicious, whether it's steak, pizza, asparagus or grilled potatoes.
Further Barbecue Guides
Here you will find further detailed instructions on how to prepare the perfect steak or super juicy pulled pork on the grill, as well as interesting background information on grilling, charcoal and meat.