ADC Conference & Trade Show: Highlights
Brendan Cook of Driftwood Spirits and whiskyblendr.com
This session by Brendan Cook of Driftwood Spirits and whiskyblendr.com was an introduction on how to do a sensory evaluation of your spirits. From how to nose and how to create a sensory-testing set, to how to form a sensory-evaluation panel and basic sensory tests to incorporate at your distillery, Cook provided comprehensive “why” and “how-to” solutions for distillers.
Attendees arrived to find Oreos on plates in front of them: three per plate. As they curiously nibbled, Cook advised that this was a simple “triangle test” – two alike things and one variant (that is, one double-stuffed cookie), an illustration of how to compose a typical sensory set.
First, Cook established why distillers should establish a sensory panel and conduct regular (at least weekly) sensory evaluations. Quality and consistency are foremost, along with the opportunity to pre-empt and product problems before they go to market, and to create a staff production and educational opportunity. As well, regular sensory evaluation should always follow process changes or transitions, to ensure a switch in raw materials, flavour, process doesn’t cause unintended changes in finished products.
He suggested that a panel should have at least six people, and meet regularly (for instance, staff could evaluate spirits once a week before their shifts). Because sensory evaluation, within one distillery, will involve a limited range of products, Cook emphasized that training panelists is less about identifying specific aromas and flavours, and more about teaching them to identify the positives of a spirit, including new-make spirit: is it clean, is it consistent, does it follow house style or have the positive attributes assigned to that brand? Evaluations can be as simple as a green (meets the standard), amber (something is off) and red (unsaleable or faulty) scale, ranking products by intensity, grouping by similarity, or describing by choosing from a predetermined range of terms.
Cook said that a sensory evaluation space should be a dedicated clean, quite spot with access to plenty of clean glassware. Ideally panelists will use the same feedback mechanism (a defined format for notes, or a platform or system for mapping/clustering/grouping aromas and flavours) and a common vocabulary for describing them: aromas wheels, tasting kits (Aromaster and FlavorActive among them) and software like Draught Lab were among his picks. He also recommended creating a base “house style” sample composed of a composite of many hearts cuts of your new-make spirit. In any library of house spirits, they should be labelled by date, batch, and ABV off the still.
Using distiller sensory sample kits from Moonshine University, Cook went through some samples, starting with clean ethyl alcohol, and covered common distillery faults, including acetaldehyde from stressed yeast; acetone and ethyl acetate, potentially introduced by wild yeast; propyl alcohol and amyl alcohol from too-warm fermentations; butyl alcohol from fusel oils in production; acetic acid from bacteria in fermentation or cleaning practices; furfual from maillard reactions in cask charring, mashing, or direct-fire on on-grain distillation); and TCA from water contamination in casks or cask taint. Acrolein, with its strong, bleach-like aroma, is a frequent cause of staff getting headaches or feeling unwell, he warned: it can concentrate through recycling tails, presence of lactobacilli and too-warm fermentation.