Freshly cut oak planks must be dried to around 10% moisture to prevent warping and splitting.

For cheaper, mass-production casks, large kilns are used to achieve this in a matter of days.For premium oak casks a much slower, original method is still used: the sun, wind and rain.

The rough cut staves are neatly – and loosely – stacked outside cooperages. Bitter sap oozes out of the oak on hot summer days, for winter rains to wash away, air-dried by summer zephyrs and lashed by autumnal gales. The longer the exposure to the elements, the finer, more gentle the flavours will be. This weathering is why Sir Francis Drake, and a bonfire he lit on a Portuguese beach in the summer of 1587, helped change the course of history.

Drake had captured a fleet of transport galleons carrying 1,700 tons of barrel staves. By destroying these staves, he knew there was not enough time to weather more oak staves, the Spanish Armada would be obliged set sail on the long voyage to Britain with their victuals stored in casks of hurriedly made, unseasoned, green oak.

The overstressed staves duly split and the casks’ contents went rotten or leaked away. The malnourished and rebellious crews, succumbing at a rate of knots to rotten food and stale water – no doubt ‘indisposed’ most of the journey – were never ready for the fight of their lives when they arrived in the English Channel. The battle was over before it began.

These days, the longer oak is weathered, the more expensive the cask will be. Only the finer oak from the very best forests of Troncais, Allier and Vosges are reserved for this time-consuming process, for up to five years of weathering. These will be destined for the finest – and richest – chateaux.

Premium French oak casks have much more powerful flavours, spice and buttered-toast, so they need to be used wisely. We use around 15% in our selection.

The staves are 20% thicker than American oak casks – not only is there more refined flavour to the oak – there’s more oak too. But it needs the weather.