Cider, charcoal burning and coppicing. Shaping the landscape of England.

Charcoal burning and coppicing are ancient arts.  Since the Iron Age high temperatures have had to be produced for iron smelting, gun powder manufacture and many other more mundane uses such as a fuel for brick making. Charcoal was the fuel. Wood was also cut, dried and used for forest glass making as it did not need quite so high a temperature, (dried beech or oak can fire a furnace to 1400C) with charcoal. And up until the introduction of coal for many furnace uses (and then coke invented by Abraham Darby in 1709 for iron working which can produce temperatures over 2000C), charcoal was used to do this for centuries and, in order to produce it, entire forests were felled.  The iron industry relied heavily on charcoal for smelting iron ore due to charcoal’s high burn heat and high carbon content. Wood in its original state cannot burn to the temperatures needed for iron smelting due to the amount of water in its make up. Iron was often smelted at 1600C.

                                          Replica Early forest iron furnace 

                    Replica forest glass furnace, not the dried wood at the side 

The fascinating process of charcoal making is one which remained more or less the same from the Bronze Age right through to the 1900s. The process begins with the building of a kiln. Historically these kilns would have been 30 foot high and burn for more than a week. The kiln itself is a more organised version of a bonfire, with a hole down the middle which is filled with kindling and then covered in hay to control the flow of oxygen. Embers – often the ‘brown ends’ which didn’t make the cut during previous charcoal production –  are then dropped down the middle to ignite the fire. This is done until the furnace is the right temperature to cook, but not burn, the wood – typically around 400 degrees Centigrade.  Once going, the top of the kiln is capped with green sticks and turf to keep oxygen to a minimum and ensure the wood bakes instead of turning to ash. The mound is then covered  with earth to stifle the oxygen and put out the fire, the kiln was then left for days or weeks depending win the size to cool down enough to be opened. Once opened the contents are spread into a single layer to allow further cooling, with the charcoal burner dabbing out any fires which reignited. The charcoal tis the sold to iron makers and increasingly from the 15th C for glass makers who often set up mobile furnaces in the forest. Prior to this time glass making was carefully controlled by the Venetians.  Because it was essential to watch burning kilns both night and day, historic charcoal burners lived on site in groups with their families. 

Dense wood like oak or hornbeam creates charcoal which burns for a long time and so is good for use in iron furnaces.  And these harder, stronger charcoals  supported a greater height in the furnace and will burn hotter, producing higher carbon iron. For glass making which requires a lower temperature most woods could be used, but what was used depended on what was local and easily transported to each mound. Beech has traditionally been regarded as the favoured wood species for glassmaking: not only did it bum well, but it possessed compounds particularly suitable as a source of alkali for the glass batch.

In England a major early site of charcoal burning was the Weald an area of dense woodland south of London a major market. The name "Weald" is derived from the Old English weald meaning "forest" (cognate of German Wald, but unrelated to English "wood" this comes from a Germanic root of the same meaning. Weald is specifically  a West Saxon form, wold as seen in Yorkshire is the Anglicised form of the word.

The entire Weald was originally heavily forested. According to the Venerable Bede in the 9th-century Anglo-Saxon Chronicle, the Weald measured 120 miles (193 km) or longer by 30 miles (48 km) in the Saxon era, stretching from near Romney Marsh in Kent, to the New Forest in Hampshire. The area was sparsely inhabited and inhospitable. Over the centuries, deforestation for the shipbuilding, charcoal, forest glass  and brick making industries has left the Weald with only remnants of that woodland cover. Clearance of the Wealden forest on a significant scale began in the 9th century, reaching a peak in the 13th and 14th centuries. Kings  soon became worried about loss of resources through the exploitation of wood. Concerns  were voiced as early as the 13th century, resulting in legislation aimed at the control of woodland exploitation, introduced in the Forest Charter of 1217 as mature oak was rapidly being used up.   In 1573, a Royal commission reported of the Wealden area. As a result of this, regulations were passed prohibiting the making of charcoal from mature wood, allowing only coppice  ( or pollarding when animals are grazed underneath) to be used so to preserve mature oak for the Navy to build warships. There is evidence that timber was being earmarked for naval use deep in the western Weald as early as 1574. In that year, 116 oaks at Kirdford are referred to in a bargain of sale as being' ... already marked with an anchor “ . And regulations introduced in an  an Act of 1581 forbade the destruction of timber within 14 miles of the Thames for fuelling iron works and additional legislation sought to protect the timber supply for shipbuilding by prohibiting felling within 12 miles of the coast. In 1574 Christopher Barker a timber surveyor wrote: - “It may please your honour to consider the several notes ensuing which do concern the great spoil and consumption of Oak timber and other woods within the counties of Sussex, Surrey and Kent by means of iron mills and furnaces …. Unless speedy remedy be provided in this respect there shall not be timber sufficient to be had within these few years and for Her Majesty to build any ships or otherwise.”’s required a dozen standard trees were left to an acre of clear felling so that regeneration through seed might follow.However regulations were hard to enforce in this mobile industry. And the destruction of mature oak continued especially with the more mobile glass charcoal users so Admiral Lord Robert Mansell persuaded Charles I in 1615 to issue a "Proclamation touching Glasses" which banned the use of wood for charcoal making the first to ban trees from being cut for charcoal to protect the supply of wood for the Navy. It was no coincidence that he owned lands with coal deposits and work had started on using coal for glass firing. Sadly for him his venture was not successful. It required the input of Sir Kenelm Digby to perfect the technique which led on the cheap strong glass that cider makers used to make sparkling cider just a little later, and before the French discovered the process and so to sparkling champagne 

Coppicing is the oldest of these tree-pruning practices and evidence suggests it has been in use since pre-historic times. The English term derives from the Old French word couppeiz, which had the meanings of "having the quality of being cut," or, "to cut with a blow." The first step in coppicing is to cut down young trees, typically about five years old, in most cases, to about six inches above ground level. This must be done in the late winter or early spring, before the buds break, when the tree is dormant and the sap has not yet begun to rise. Otherwise, there is the risk of doing the tree permanent damage. The remaining tree stump is known as the "stool," which will gradually increase in size over the years. When the next growing season begins, the stool will put out new shoots which will sprout fairly quickly from its living base. These new shoots are allowed to grow until they achieve the length and thickness needed for the purpose to which they would be put, from fuel to craft materials.

One of the greatest advantages of coppicing is that it is not necessary to replant a coppiced tree, it will continue to grow and produce new shoots for many generations. For example, an ash tree left to grow naturally can live for about 200 years, but an ash tree which is regularly coppiced can survive for 800 years or more. A woodland of mostly coppiced trees is known as a copse. Each coupe (or coppiced area within   a copse) was harvested on a particular cycle, since the trees in each would be at a different stage of regeneration. Depending upon the species of tree and the purposes to which these young shoots would be put, any given coupe might be coppiced on a scheduled cycle of from one to as many as ten to twenty-five years, though three to five years was the average growing cycle for most crops. In a large forest, this cyclical harvesting method could mean that the trees in a few of the coupes would be harvested each year, usually in the winter, while the majority of coppiced trees would be allowed to continue to grow until it was time for the coupe in which they stood to be harvested. Thus, by harvesting coppiced shoots on a scheduled rotation, the woodsmen were generally assured of a mature crop in some part of the copse or forest each year. Most deciduous or broad-leaved trees can be coppiced. The species of trees which best lend themselves to coppicing are those in which the sap most completely descends into the stump and roots during their dormant period. Those species which can be coppiced most vigorously are ash, hazel, lime, sweet chestnut, hornbeam, birch, elm, plane, sycamore, holly, alder, oak and willow trees. Trees with less vigorous growth, such as beech, poplar, and wild cherry can be coppiced, but they will require several more growing cycles to produce stems of a useful size. 

Recently coppiced stool

                                               After one year. Willow 

                                                         Coppiced Oak 

As an example of the increase use of wood for fuel in these industries, between 1530 and 1590 the price of wood suitable for making charcoal rose from about 4d a cord [usually 128 cu ft] to 2s (24d), while the price of charcoal quadrupled between 1540 and 1600. It has been calculated that to keep a blast furnace operational required about 2,500 acres of coppiced woodland. One furnace and its associated forge could be supplied with charcoal from a radius of not more than three miles. Whereas a  large warship of the time would have required about 2,000 oak trees for its construction That corresponds  to 30 hectares of forest. The Royal George, a 100-gun ship, launched in 1756, used 2,309 loads (a load being 50 cubic feet) of straight oak and 2,306 loads of compass oak (curved grain). 

Charcoal burning is still carried out commercially in  Europe, in  Romania, Poland, Slovenia, and Switzerland. In the UK it is performed to maintain a coppiced agricultural landscape. However in many areas not routinely coppiced the trees have regrown to near full height but with multiple trucks from the  ground level stump. 

                                            Old coppiced lime trees 

Now only 25% of the Weald his forest.

England is like a well worn pair of shoes. Lived in for centuries each has left its mark on the landscape. Charcoal burning, glass making ( and sparkling cider making in glass bottles and served in fine glasses such as the Scudamore flutes), shipbuilding and politics all entwine into a complex history that has an effect on the countryside. That can still be seen.