Gorun, more suitable for joinery and barrel making than oak

I've spent the last little while researching gorun and other cousins of the Quercus genus. It all started with a wonderful gorun timber posted on a group by a lucky carpenter. The fact that gorun is very similar to the pedunculate oak (Quercus robur), which I wrote about here, was nothing new. We know they are so similar that many treat them as European oak, making no distinction between the two species. But I set out to discover the differences, both in the tree and the wood. I have to admit that it was not an easy task, as there is very little information on this subject, especially on the wood. However, I did learn something.

The Gorun, an oak that loves dry soils

From the Latin name of the gorun - Quercus petraea - we deduce that it is a stone-loving tree. It does not grow on mountain tops, but unlike the pedunculate oak we find it mostly in hilly and low mountain areas, sometimes even reaching up to 1000-1200 m. While the oak is more selective about the soils it grows in, the gorun is less fussy, the only soil it won't accept being very wet. For this reason, in Romania the gorun occupies larger areas than the oak, reaching 10% of the forestry fund.

Gorunul, sessile oak or Irish oak in English, is widespread in most of Europe, reaching as far as the Caucasus and Asia Minor. Northwards it reaches as far south as the Scandinavian peninsula and southwards to the northern Iberian Peninsula, southern Italy, the Balkans and Turkey. It rises from sea level in the north to 1200-1300 m in the Alps and even higher in Turkey. It is the dominant species in the mixed deciduous forests of temperate Europe. It occupies large areas in France and is the raw material for the manufacture of highly prized barrels. It is the national tree in Ireland and the unofficial emblem of Wales.

Gorunia, which belongs to the deciduous deciduous category, can grow up to 20-40 m tall, reaching 1-3 m in diameter. The tall, straight stem with a rich crown is covered with smooth grey-grey bark that becomes increasingly wrinkled as the tree ages. Typically lives to 400-600 years old, but some specimens can exceed 1000 years. The oval, evenly lobed leaves are 7-14 cm long, 4-8 cm wide and have a 1 cm long petiole. It has both male and female flowers, and wind pollination produces the fruit - a 2-3 cm long acorn, green at first, which ripens to brown in six months.

Differences between Gorun and Pedunculate Oak

Although the trees are also similar, it is much easier to tell the difference between the gorun and the oak than between their wood. Most differences are seen in the leaves. Gorun leaves are more elongated, uniformly wavy, rectangular in shape, not very prominent veins and 1 cm long petiole. Oak leaves are shorter, unevenly wavy with smaller lobes at the base and apex and larger in the centre giving them a lozenge-like appearance, prominent veins and a very short, almost non-existent petiole. The colour of the gorun's leaves is dark green, with a slight purple tinge on the back, a shade not found in oak.

Another difference is related to acorns. In gorun, acorns have no tails, i.e. they are sessile, hence the name. They are fixed on the branches, unlike those of the oak, which have tails and hang from them.

There are also differences in the preferred locations of trees, but this is not a very clear indication, as in many areas they coexist together. In such situations they can give rise to natural hybrids - Quercus x rozacea. The oak prefers lowland areas rich in water and nutrients, while the gorun is less demanding in terms of nutrients, preferring acid and sandy soils at altitudes above 300 m, with as little water as possible. Gorun is associated in forests in warm hilly areas with carpen, teepee and fagulwhile the oak is found in the lowland forests, along with frasin and maple.

The great similarity between the two species has often led to them being considered the same and being called oak. Charles Darwin himself mentions in his book On the Origin of Species (On the origin of species) that there are sources that treat them as different species and others that consider them to be varieties of the same species.

Characteristics of Gorun wood

In cross-section through the gorun wood you can see the sapwood and heartwood which are not always very well defined. Also clearly visible are the annual rings, consisting of two zones, the early wood, deposited in spring, more loosely packed and with 2-4 rows of large pores, and the late wood, in summer, more densely packed, with small and very small pores in a radial arrangement. Unlike oak, gorun has more uniform and narrower annual rings due to slower growth in hilly and mountainous areas.

The sapwood is yellowish white to brownish and the heartwood is yellowish brown, with many other colourings that depend very much on the area of growth. The fibre is coarse, sometimes irregular and twisted, depending on growing conditions. In fact, growing conditions in less friendly areas lead to the appearance of particular colourings and fibre patterns in the wood, making it very special. Like oak, it has visible medullary rays.

The average density of dry gorun is 710 kg/m³, slightly higher than oak. It is very resistant to decay, processes well by hand and machine, and has a specific odour like oak. Tannin can sometimes cause problems when finishing or in contact with metal. It binds smoothly and looks very well oiled and waxed.

It splits and works more easily than oak, which is why it is widely considered superior to oak in joinery projects, furniture and barrel making. It is, however, harder and less elastic than oak, so it is considered inferior to oak in building and house structure projects.

Uses

According to the above, gorun is used to make furniture, for carving and for making barrels (cooperage). It is very suitable for making craft or interior decorations and fittings. Its very good resistance to rotting makes it suitable for building fences, garden furniture, decking and other outdoor projects.

Regarding manufacture of barrels, oak and oak are considered very different because of the distinct organoleptic characteristics they bring to the wine. Their tannins and flavours are different in both quality and quantity. Oak has more porous wood and releases the strong tannins into the wine faster. Gorun wood gives the wine a smoother, softer and more aromatic tannic taste. However, they vary considerably depending on the origin of the oak and the growing conditions of each tree.

The bark of the gorun is also used, which is very rich in tannin like that of the oak. The tannins extracted are used to tan animal hides. The leaves and fruit are used in herbal medicine. Acorns are the food of many forest animals.

I hope you find the information interesting. If you have worked with gorun, tell us about your experience. We would be happy to supplement the article with information directly from the source. And if you have any questions or queries, please leave them in the space below. I will certainly answer them.