Reviving the lost lessons of the past

Silas slaps the sawn-off section of an oak trunk for emphasis. ‘Look closer,’ he says, and we do. ‘There are two types of year rings. The lighter is the spring growth. It’s the same every year, but it contains lots of little straws bringing water and nutrients up through the tree. That makes it brittle.

‘The summer and autumn growth gives a darker and denser ring. So you need a wood with a higher proportion of summer/autumn growth to build a strong boat.’

Silas is one of a team at Roskilde in Denmark using traditional tools to construct modern facsimiles of Viking ships and other boats from the pages of Nordic history – clinker-built craft, ships from the Faroes constructed without the aid of any written plans.

Look closer: There are parallels and contrasts between shipbuilding and cask construction

How did the Vikings do it? Take a good, straight oak log, split it into halves, then quarters, eighths, sixteenths. Then use an axe (broad, rather than bearded, since you ask) to plane the wood. An axe? It does the job – and it saves having to make another tool.

Silas’ sermon on boat-building is part of the launch of Highland Park Valkyrie and the single malt’s new ‘Viking Soul’ brand ethos. The idea is to draw parallels between boat and cask construction (Martin Markvardsen and Keith Moar from Highland Park are here too) – but, in the end, the differences are as fascinating as the similarities.

While the oak used for whisky casks is allowed to season for a year or two, the Vikings wanted their wood green for its flexibility. Heating it to 60C in the fire liquefies the lignin (the glue holding the grains together), allowing the wood to be twisted, grain-against-grain, moulded to the shape required, clamped and allowed to cool and set.

Green wood was also vital for the tannins that helped seal the vessel – the same tannins that whisky-makers are generally keen to prevent from finding their way into your glass.

The level of knowledge about these ancient techniques is astonishing. The museum at Roskilde holds the remains of five Viking ships, scuttled in the main channel approaching the town as a blockade to ward off invaders well over 800 years ago.

Clinker-built: The workshop at Roskilde aims to revive ancient techniques

By examining the fibres of the wood and checking the growth rings against an extensive database, historians can tell that the two smaller ships were made from oaks growing near Roskilde in about 1030. The biggest ship – a King’s Ship, 30m long, built for speed and to carry up to 75 warriors – has a keel constructed from a tree felled near Dublin in 1042. Dublin? Those Vikings got around.

Why scuttle such an impressive vessel? Because it was dying. After 30-40 years of service, the iron nails fixing the planks had been rusted by the salt waters, expanding and cracking the hull.

So how about trying to construct a Viking ship in the 21st century, using old methods and tools (but copper nails for greater longevity)? Sure. But it took Silas and the team at Roskilde four years and 50,000 man hours.

Compare this to the Viking Sagas, which talk casually of building a ship in a northern winter – six to eight months – and, even allowing for modern employment law and health and safety rules, something doesn’t quite add up.

It’s the same with the sails. The Vikings’ adoption of the sail – some time between 750 and 850 – revolutionised their ships, allowing them to cross the North Sea, discover Greenland, Newfoundland. No sails, no Vikings.

But these sails were big – 112sq m big – and each of their many strips was hand-woven on a loom. At Roskilde, the museum’s skilled weaver can complete one strip of 15cm in a day (5-6 hours’ work). How the hell did the Vikings do it? Again, it doesn’t add up.

Plane truth: The Viking axe was a multi-purpose tool, not the bloodthirsty weapon of myth

The answer is simple, says Silas. There are some skills that have just been lost – honed and passed down by word of mouth and practice of hand through the generations, then forgotten in the bustle and din of industrialisation. In the rush to move on, something vital has been mislaid.

Despite a weakness for nostalgia, our Darwinian view of evolution tends to assume that human beings are constantly finding better, faster, more efficient ways of doing things. From Olympic sprinters to computer chips, it’s all about progress.

Roskilde calls that view into question and, given the parallels being drawn with whisky, makes you ponder whether a multi-billion pound industry’s drive for increased efficiency, economies of scale and profitability has unwittingly led to something being lost along the way.

Barley, yeast, fermentation and distillation techniques, cask maturation. What can whisky’s written record teach us? Are some of the secrets of the past lost to us now – as with the Vikings – or can they be resurrected and revived, moulded into something fresh for the 21st century?

Might, progress, after all, turn out to be a two-way street?