Why Blend Whiskey?
There are a huge number of factors that can influence a whiskey's flavor before and during the aging process. While process and science can significantly improve the consistency of fermentation and distillation, all bets are off once the white dog hits the barrel. Different parts of a rickhouse will experience different temperatures, causing variation in the amount of extraction of barrel compounds and evaporation. The barrels themselves can have variability in wood grain, density, and chemical composition that further influence that barrel's unique character. Many afficionados take joy in the search for "honey barrels" or specific single barrels that may stand out from the pack, but this can cut both ways with poor picks being a bit of a let down. For established brands with flagship products, ensuring consistency in flavor is critical to maintaining their fanbases and reputations. Enter "Blending", quite simply the process of mixing together different whiskies to achieve a desired flavor profile. Balancing flavors by mixing is a common process used in wine as well as spirits and was even more critical before modern production methods and quality control procedures.
Blended Whiskey vs. Batches
With the exception of single barrel or single cask whiskey, pretty much all whiskey is blended in some way and bears the fingerprints of a talented composer, though that is distinct from it being a "blended whiskey". Blends of the same mash bill whiskey by one producer will typically be referred to as "batches". These batches can range from 20-30 barrels for craft producers to around 250 barrels for larger small batch producers like Four Roses. Major players like Jim Beam may not even count the number of barrels exactly in a batch because the vat size is so large, opting instead to weigh the contents (alcohol expands a good bit with temperature, but the weight is constant). Even bonded whiskey, which must be the product of a single distillery and distillation season, will typically be batched to ensure consistent flavor and quality. This single season requirement actually adds a good deal of complexity as many excellent value bottles like Wild Turkey 101 will leverage a range of barrel ages to ensure a consistent taste. Older juice may be necessary if there have been a few mild weather years causing some younger barrels to retain a green or grainy taste. Similarly younger spirits may help balance out some over oaked qualities in any more aged stinker barrels.
True blended whiskies will be mixtures of different mash bills or producers entirely, and labeling that describes a "Blend of Whiskies" is typically regulated in major whiskey producing countries. In Scotland, Blended Malt Scotch Whisky is a blend or two or more single malt scotches that have been distilled at more than one distillery. In the United States, blended whiskey must contain at least 20% straight whiskey (and may be labeled as "whiskey - a blend"), while bottles labeled "a blend of straight whiskey" consists of straight whiskies from different states but does not contain neutral spirits. Brands like Johnnie Walker and Dewar's pretty much exclusively offer blended whisky and the vast majority of scotch consumed is blended.
The Blending Process
An equal labor of subjective experience and data, the blending process pairs information such as mash bill, location, age, cask type, and lab chemical readings with human origin observations on flavor and feel.
Sampling & Selection
To start the blending process, the Master Blender tastes and records notes on a stunning number of barrels. Master blenders/distillers are the chief tastemakers of whiskey and have a staggering array of duties under their job description. They may be assisted in choosing their samples by some sort of chemical analysis (density, turbidity, pH, and component analysis) or by pulling sample selections across a variety of product attributes. A cask management information system of some type likely facilitates this process, and there may be a data analytics or other product analysis team to help systematically crunch through the numbers at the direction of the expert taster.
Sandy Hyslop, a Master Blender for Chivas, noted that:
A Master Blender is someone that has a fantastic sense of smell. Your nose is by far the most important tool as a professional blender. To put it in context, I probably nose 1,500-2,000 samples a week yet taste around five. There are far more flavor receptors on the nose – almost 5,000 of them in fact!
Japanese whisky maker Suntory takes blending so seriously that it employs a team of five blenders who each sample between 220 and 250 whiskeys daily.
During their observation they are sure to note, not just the types and combinations of aromas present, but also the intensity of those flavors. For larger operations, there may be whole teams of people collecting these pieces of sensory metadata. You may hear this referred to as a "Sampling and Recording" program. In many cases, individual barrels will be grouped together into similar "lots" with the same set of characteristics to facilitate blending at a larger scale.
Blend Design and Composition
Depending on the scale and size of the company, there may be a variety of processes used, but the core operations are design, sample construction, and refinement.
Johnnie Walker's Master Distiller Emma Walker manages an inventory of over 11 million casks. She starts with a design brief which notes the specifications for the blend including: one-off/recurring, legacy brand, expected volume, price point, and current inventory. From there, they execute an iterative process of building the blend first on paper and then in samples based on the desired characteristics. Batch samples are analyzed for their merits and may be additionally tempered through the addition of other component spirits. In this case, the process relies on many teams coordinating to prepare data on component spirits for the Master Blender in what ends up resembling the mother of all Excel Spreadsheets.
Nikka's Chief blender Tadashi Sakuma mentions:
In the case of developing a new product we picture the aromas and flavors required for the new product. Then from the thousands of lots of whisky we choose the candidates for the product, make a formula and blend. We repeat this process until the product matches what we first pictured. The formula is finalized through consumer research and fine-tuning. In the case of updating an existing formula, the most important thing is the consistency in taste profile and quality. When we run out of a particular batch of whisky used in a product, we then have to replace it with something else. We choose a batch that has a similar profile to the one that is gone and repeat the experiment until the taste profile and quality matches the original formula.
The key distinction in Nikka's process is the use of sub blends, which are combinations of smaller numbers of barrels as an intermediate step. They handle balancing out any off flavors or crazy tastes at this level to allow for a finer level of control in the final blending step.
In all cases, blending is an iterative process; there are few cases where a blend is dumped and immediately bottled without further alteration.
The Future of Blending
While processes vary, the goal of blending in creating a consistent and targeted product is clear. Whiskey takes time and one of the bigger challenges for blenders these days is that aged whiskey stocks are relatively low due to increasing demand. With those older stocks diminishing, we've seen age statements removed from many products. This is because the youngest component spirit influences the label age on the bottle. A blend of 1% 6-year whiskey and 99% 10-year whiskey can only be labeled as six years old. Like an artists' paints, blenders have less spirits to chose from when crafting new product. Major producers are increasingly reliant on on-site or third party labs and information systems to help them manage their voluminous inventories, and may have a balance skewed towards data and science. Small operations often still taste and batch individual barrels using little more than their highly honed nose and tongue. Regardless of how you may feel about a particular "blended whiskey", expert mixing of whiskey will continue to be one of the highest expressions of skill in the trade.
