Notes on wood – October 2018
Fast and Slow heat
Some wood has a faster flame, like Silver Birch. It’s quick to combust and has a stable and constant heat profile. It’s aromatics are zesty, mineral and clean. In contrast Oak has a slower to flame timeline, due to its inherent density and chemical compound and material structure. Once underway it burns consistently, with a notably classic aromatic profile all through the burn cycle, it colliers at a mid-way stage and hold its structure by way of forming a good and consistent coal. It’s super stable, the king of the woodland, a truly noble fuel for food.
The Aromatic Spectrum
Think of wood as existing on an aromatic spectrum, from dark to light, sweet to sharp. Imagine it sits in a sphere, more dense at the centre and lesser towards the outer realms. The journey through this world, where notes sharpen or dissipate and weight varies or strengthens is both complex and compelling. And to all this add air, the stuff we breathe, the oxygen we need and this takes us onwards and further in the journey, oxidising the compounds towards a final ‘curing’ of the whole process. Much like any ingredient or spice, wood and its complexity adds something beyond all of our comprehension to food, it’s the sweet spot, where the magic happens and the combinations are seemingly endless.
Wood curing and seasoning
Wood carries a great deal of moisture when fresh felled, which in turn makes burning it initially difficult and often challenging. To get the best from wood we take it through a curing process, where we drive off moisture and bring the wood to the level we know it performs best. However, as with many other processes in the food world it requires a certain approach. Think of cheese and meat and even some vegetables like squash that require time and careful handling to get the best from them. Wood is no different, it’s an organic material, full of compounds and elements that we want to preserve and those of which we want to lose.
Moisture is held in two ways within the structure of a tree and when the tree is felled in the year makes a significant difference too, with just before winter being optimum and early spring when the sap rises being more challenging. But the spring wood is awash with new life compounds as the tree is in the process of creating a new canopy and to do so it absorbs minerals and other elements from the soil surrounding it. And these elements are the things we love to work with. To do this we experiment with timings and forcing or bringing on the wood to get the best from it, before moulds and spores get a chance to break down and attack the polysaccharides and other elements. We find oak benefits from time, where we take Birch early and Apple too, giving them longer in the kiln, but capturing a freshness of youth in the final finish, much like winemaking does; we play with oxidation and age.
Kiln drying wood
Kiln-drying is a process that helps to take wood through a faster seasoning process. It’s a controlled environment within the chamber which has heat and moisture control and on the face of it is relatively simple. But the reality is both simple and complex. To ‘cure’ wood you heat the chamber which in turn drives out the moisture, in a sense you ‘cook’ the wood. But cook the wood too hot and fast and you affect the compounds within, which alters the aromatic very profile you’re trying to preserve. Which for firewood isn’t a problem, but wood for food has a different set of requirements and we treat our wood accordingly.
Wood and food pairings
Classically pairings are made with Fish and Meat, but more and more as we explore the cultures of the world we find a greater joy with vegetables, breads and fruits getting a lick over the flame, so i’m not going to push hard on the pairing side only to say; think about what you’re looking for, experiment and ask us too.
There are some obvious classics. Oak and salmon, Oak pretty much any oily fish for that matter, but then Applewood works well here too. Pork and applewood. Beef and Oak, along with others. Sweet Chestnut or Apple for crustaceans. Pear or fruitwood with cauliflower and other structured vegetables. But I’m cautious of over specifying and pairing as we’re endlessly discovering things as we go through the process. In Sweden aged beef and Birch are paired, where Finland pairs Alder with Salmon curing and that in turn produces a fruiter, sweeter outcome.
Vinewood and spring calcots, beef and milk fed lamb, seafood and vegetables from France and Spain. And the list goes on, it’s part of the fascination, and then there’s blends and combinations to consider, along with timing and intensity of course.