The Notes
Peat Smoke and Smoky Notes
Peat smoke is the smell of a slow fire cut from the bog: phenolic, earthy and faintly medicinal, and the reason some whisky tastes of the moor.
Peat smoke is the smoke of burning peat, the dark, partly decayed plant matter that builds up in waterlogged bogs, and it smells phenolic, earthy and faintly medicinal: a fire banked low in a cottage grate, or the inside of a whisky glass. In perfume, a smoky note is put together from materials that carry smoke of their own: tars, woods, resins and a few aroma molecules.
Where it comes from
Peat forms where standing water keeps the air out and dead plants cannot rot properly. Sphagnum moss is one of its commonest parts, though a bog may also hold heather or old wood. Cut and dried, it has long been burned for heat in Scotland and Ireland.
It also dries barley. In Scotland, and above all on Islay, maltsters burn peat beneath the damp malted grain, and the smoke leaves behind a family of compounds called phenols: phenol itself, the cresols and guaiacol among them. Whisky writers give each a character: carbolic for phenol, medicinal and bandage-like for the cresols, wood smoke for guaiacol. The bog matters too. Research on peats from Orkney, Islay and the Scottish mainland found that woody and mossy peats give different phenols, and heather-rich Orkney peat is said to burn to a gentler, more heathery smoke. Oddly, a piece of dry peat smells of very little until it meets the fire.
A second smoke: lapsang souchong
Lapsang souchong is a black tea from the Wuyi Mountains of Fujian, in south-east China, dried over pinewood fires. Chemists who analysed it found that its two most abundant aroma compounds, longifolene and alpha-terpineol, come from the pine smoke, along with guaiacol and its relatives. So the tea and the whisky share a molecule, and both smell of a hearth: one resinous and piney, the other tarry and wet.
How perfumers build smoke
Birch tar is made by heating birch bark without air. It smells of a wood fire and tanned hide, and it gave Russia leather, the hides oiled with it after tanning, their famous scent. It is used in purified or rectified grades, and IFRA standards cap how much of it a perfume may contain. Cade oil comes the same way from the wood of the prickly juniper, Juniperus oxycedrus, of the Mediterranean, and is rougher, more like a campfire. Guaiac wood oil, steam-distilled from the heartwood of Bulnesia sarmientoi in the Gran Chaco of South America, is softer: dry, smoky and tea-like, with a curious hint of rose. Resins such as styrax and labdanum add a smoky edge of their own, and guaiacol and its cousin 4-ethylguaiacol are used in traces for smoked, phenolic effects.
In our fragrances
Highland ends on a peat smoke note with guaiac wood and damp moss, after a heart of wild heather, smoky lapsang souchong tea and labdanum: the lodge late in the season, boots drying by the fire. In Saddle Room the smoke is far quieter, a thread of birch tar running through hay absolute and suede towards a leather accord. The Drawing Room Candle burns with smoked black tea, bergamot and beeswax. Highland suits tweed season well, and the Discovery Set lets you try all six side by side.