blending is a long-practiced art form by spirits producers whereby different lots of spirits, either from the same distillery but with different maturation or from different distilleries and, commonly, with different styles or lengths of maturation are combined to form a harmonious whole. Blending dates back at least to the eighteenth century, when British rectifiers made a practice of stretching out expensive imported brandy and arrack with cheap domestic molasses spirit and Dutch brandy wholesalers “adjusted, that is, mixed, coloured, sweetened and made up” their spirits before resale, according to W. A. Smyth’s Publican’s Guide. See rectification. The next century saw the British apply the art to rum and whisky and the French adopt it in brandy making, where it is now one of the building blocks of the trade. See élevage.
Blending gained a new prominence in the middle of the nineteenth century with the widespread adoption of the column still in Britain and the cheap, light, relatively clean whisky it produced. In 1860, by act of Parliament (23 and 24 Victoria, cap 114), British rectifiers were allowed to blend pot- and column-produced spirits in bond; this was the beginning of the modern blender’s art (and the end of the old one: the same act forbade the blending of British and foreign spirits). See excise, taxes, and distillation. While Ireland and Jamaica both resisted the column still until the 1950s, blended pot- and column-still spirits rapidly became the norm in Scotland, Canada, and parts of the British Caribbean.
Nowadays many spirits are pot-column blends, where the pot-still product provides the intense flavor and the column-still one lightens it, brings out accents in it, and—just as importantly—makes it available at a manageable price. Many scotch and Irish whiskies, a number of popular rums, and most American applejacks and Dutch and Belgian jenevers are blends of this sort. Nowhere has the blender’s art been more important than Canada, where it has been at the heart of Canadian whiskey making since at least the 1890s. In fact, we can use Canadian practice as a model for blending in general.
Modern blending is not simply pouring barrels of whisky into a vat and stirring. It requires consideration of all the variables in production from the largest to the smallest. A master blender has to have a keen understanding of all the distillery’s processes and how the flavors from source grain, brewing and fermentation, and distillation interact with the aging process.
By this standard, blending starts with the selection of raw materials. In general, for whisky production corn gives a sweet-creamy expression, barley a nutty-cereal note, rye a spicy character, and wheat a bready nuance. The quality of the raw material is also important, as negative characteristics can impact the flavor of final blends. For example, when fungus grows on poor-quality grain, it produces geosmin or 2-methylisoborneol (MIB), which survive distillation and give whisky a musty character. If these compounds are at detectable levels in the finished product, a blender can either mix the whisky with better batches or, in a worst-case scenario, send it to be redistilled.
Fermentation is also important to the blender. Along with ethanol and carbon dioxide, yeast also produces compounds with fruity, floral, grassy, soapy, or sulfurous character. Brewers in a whisky operation can influence these flavors by manipulating a number of fermentation parameters such as temperature and pH or oxygen levels, so it is important for the brewer to work with the master blender to establish a consistent baseline of flavors that are generated by the fermentation process. See fermentation.
The master distiller will also influence the final flavor of the whisky by selecting the method of distillation. See master distiller. Two passes through a column still creates a lighter spirit that removes the majority of the yeast congeners and grain characteristics; this is often termed a “base whisky”; it will usually be made from corn. “Flavoring whiskies,” on the other hand, can get one pass through a column still, which produces a full flavored spirit that has retained a good deal of the grain and yeast characteristics, or they can go through a pot still, to concentrate the desired characteristics and remove the unwanted heads and tails (these whiskies perform the role in a Canadian blend that malt whiskies do in a scotch one). No matter the type of distillation method, the master blender must be able to understand how to work with the spirits that are produced by the distiller to maintain existing recipes or to create unique whisky styles.
barrel.Finally, after aging the master blender will construct a recipe by mixing percentages of whisky from specific grain types, brewing parameters, distillation methods, and barrel types. Blenders are like a conductor with an orchestra where all the parts, whether great or small, are considered in the final development of the whisky recipe.
See also whisky.
Cooper, Ambrose. The Complete Distiller. London: 1757.
Kunze, W. Technology Brewing and Malting. 2nd ed. Berlin: VLB Berlin, Verlagsabteilung, 1999.
Livermore, D. Quantification of Oak Wood Extractives Via Gas Chromatography: Mass Spectrometry and Subsequent Calibration of Near Infrared Reflectance to Predict the Canadian Whisky Ageing Process. Edinburgh: Heriot-Watt University Life Sciences, 2012.
MacKinnon, T. L. The Historical Geography of the Distilling Industry in Ontario: 1850–1900. Waterloo, ON: Wilfrid Laurier University, 2000.
Piggott, J. R, K. Y. Lee, and A. Paterson. “Origins of Flavour in Whiskies and a Revised Flavour Wheel: A Review.” Journal of the Institute of Brewing 107 (2001): 287–313.
Smyth, William Augustus. Publican’s Guide. London: 1781.
By: Don Livermore