Court of Master Sommeliers Deductive Tasting Method

The Deductive Tasting Method (DTM) is the blind tasting approach of the Court of Master Sommeliers. A GuildSomm guide by Martin Beally calls its grid the shorthand for the deductive tasting format; in Beally's own version of the grid, the taster works through sight, nose, structure and palate to an initial conclusion (including climate and possible varieties) and a final conclusion naming variety, origin, quality or classification, and vintage. Writing in 2016 as the Court's Examination Director, Shayn Bjornholm MS called the DTM a system directly linked to theory rather than a recognition game. At the Master Sommelier level, Decanter reported in 2013, candidates face six wines in 25 minutes and must identify grape, vintage, quality level, country and region for each.

Definition and Origin

The Deductive Tasting Method is the structured approach to blind tasting used in the Court of Master Sommeliers examinations. In a guide published by GuildSomm, Martin Beally calls the grid the shorthand for the deductive tasting format, which guides the taster through the process of blind tasting, and points readers to the Resources area of the Court of Master Sommeliers-Americas (CMS-A) website for its current version. Deductive tasting, in Beally's words, relies on the taster analyzing all of the clues in a wine and then making a logical conclusion. He sets it against recognition tasting, in which the brain takes one piece of information and looks only for what supports it, a habit he names confirmation bias. Writing in 2016 as the Court's Examination Director, Master Sommelier Shayn Bjornholm described the DTM as a system directly linked to theory, not a gift, a magic trick or a recognition game.

  • Matt Stamp MS wrote in Decanter (2013) that after an introductory class, aspiring Master Sommeliers pass three progressively demanding exams: Certified Sommelier, Advanced Sommelier and, by invitation only, Master Sommelier; blind tasting proficiency is required in all three
  • Wine Spectator (2018) lists the Court's four levels of difficulty as Introductory, Certified, Advanced and Master Sommelier
  • Beally's example: a banana aroma in a red wine might lead a novice straight to Gamay Noir, while a deductive taster links it to whole cluster fermentation and keeps Pinot Noir, Grenache and Syrah in play
  • If the same wine also shows low visual intensity, a garnet color and herbal notes of cola and sassafras, Beally writes, the set of four facts together builds the case for Pinot Noir
Key Facts
  • GuildSomm guide author Martin Beally defines deductive tasting as analyzing all of the clues in a wine and then making a logical conclusion; the grid is the shorthand for the deductive tasting format
  • Beally's version of the grid runs Sight, Nose, Structure, Palate, Initial Conclusion and Final Conclusion; he notes he placed Structure before Palate and added categories that do not exist on the CMS-A grid
  • In Beally's grid the Initial Conclusion covers old world or new world, climate, possible varieties, possible countries and age range; the Final Conclusion covers variety or blend, country of origin, region or appellation, quality or classification, and vintage
  • Decanter (2013): after an introductory class, aspiring Master Sommeliers pass the Certified, Advanced and, by invitation only, Master Sommelier exams, and all three require proficiency in blind tasting
  • Wine Spectator (2018): the Master Sommelier tasting segment is a blind tasting of six wines in 25 minutes, one of three segments each administered once a year
  • Decanter (2013, Gerard Basset piece): the Court requires a 75% mark or better in each of the three sections, and candidates never receive an official score
  • In October 2018 the Court of Master Sommeliers Americas voided its September 2018 tasting exam after its board received a report that a Master Sommelier had improperly disclosed information about the wines

Why It Matters

GuildSomm's study guide to tasting describes blind tasting in general terms: tasters use sensory evaluation of a wine's visual, aromatic, flavor and structural characteristics to catalog clues about its viticultural characteristics, climatic growing conditions, winemaking methods and age, then use theoretical knowledge, logic and deductive skills to identify its quality level, grape variety or blend, country of origin, region or appellation, and vintage. Bjornholm wrote that using the DTM cements why a wine tastes the way it does by linking the sensory analysis to the theoretical causes of what is being tasted, and establishes the typicality of the world's paradigms and quality levels within type. Mary Margaret McCamic MW, writing for GuildSomm, says blind tasting in an exam removes any bias a taster might have toward a wine and lets candidates show they can evaluate it accurately and objectively.

  • Bjornholm (2016) wrote that learning the Deductive Tasting Method and applying it with skill and acumen is "the ONLY way to pass the Deductive Tasting portion"
  • Bjornholm also noted that Master Sommelier mentors are not allowed to share how wines are scored in exams
  • Stamp wrote in Decanter (2013) that blind tasting requires practice, not innate ability, and sharpens the ability to communicate a wine's character in an objective and meaningful way
  • McCamic reports that Doug Frost, MS, MW, still incorporates almost every aspect of the CMS grid when he tastes, expanding it to consider the bigger picture
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The Grid in Detail: Sight, Nose, Palate

Beally's guide prints his own personal grid, which he says changes the structure a bit from the standard grid. Its Sight section covers clarity and brightness, intensity, primary color, secondary color, rim color, staining, viscosity, and gas or sediment. Its Nose section opens with faults, intensity, condition or maturity, and fruit condition, then works through white and red fruit families and non-fruit categories including floral, vegetal, herbal, spice, rotundone, stem inclusion, lees, malolactic fermentation, oxidation, organic and inorganic earth, and oak. Structure covers residual sugar, body, texture, tannin or phenolics, acid and alcohol, followed by balance, complexity and length, and the Palate section repeats the nose categories. Beally lists his changes: he expanded a generic non-fruit category into twelve, added a floral intensity category that does not exist on the CMS-A grid, and placed Structure before Palate, noting that some tasters prefer the palate after structure.

  • Reciting the grid from instinct, Beally writes, means approaching each wine consistently and correctly without spending mental processing power on remembering the grid
  • In an exam, he adds, automatic recitation ensures every box is hit and makes the candidate easier to grade
  • Beally warns that many novice tasters default to an "all medium plus" mentality when evaluating the structure of a red wine
  • Each variety has its own tasting paradigm, the way the grid manifests for that wine; for structural scales, the WSET Level 3 Systematic Approach to Tasting Wine (2022, Issue 2) rates acidity and tannin from low through medium(-), medium and medium(+) to high

Initial and Final Conclusions: From Clues to Identity

The grid ends in two conclusion stages. In Beally's version, the Initial Conclusion covers old world or new world, climate, possible varieties, possible countries and age range, and the Final Conclusion covers variety or blend, country of origin, region or appellation, quality or classification, and vintage. He adds a Why? box to both, a category he says does not exist on the CMS-A grid, so that a statement such as an old world wine from a cool climate has to be supported with data gathered from the tasting. At the Master Sommelier level, Stamp wrote in Decanter (2013), a candidate faces six wines and must, in 25 minutes, identify the dominant grape variety, vintage, level of quality, country and region of origin for each, while also describing tannin, alcohol, acidity and sweetness, aromas, length of finish and visual cues.

  • Beally advises settling the variety first and then its origin, because markers for variety always lead to the variety while winemaking techniques can be applied to any wine
  • He defines objective factors as clues that significantly limit the options because they connect to certain grape varieties, vineyard characteristics or practices, or vinification techniques, and groups them as Varietal, Vineyard and Vinification
  • In general, Beally writes, Varietal objective factors should be weighed the strongest, Vineyard medium, and Vinification least
  • Basing a conclusion on several objective factors, he argues, forces it to rest on multiple sources of information, not just one

Climate, Vintage, and Structural Deduction

Beally describes vineyard objective factors as coming from the environment in which a vine is grown and how it is cultivated; they are typically indicative of climate (and therefore region) or vintage, and are non-exclusionary, so their absence does not necessarily rule a wine out. He writes that fruit condition is dependent on climate: overripe fruit character tends to occur only in the hottest climates or where grapes shrivel on the vine, and dried fruit in an aged wine would be accompanied by a duller visual with brown notes. Fruit that becomes tarter on the palate, in his account, is generally indicative of an old world wine, since old world regions broadly tend to have climates more conducive to tarter expressions of fruit; he contrasts California Pinot Noir with red Burgundy. Stamp gives a varietal example in Decanter: aromas of green bell pepper or grass are associated with pyrazine compounds in Sauvignon Blanc, so a taster who smells them may logically lean toward Sauvignon.

  • In Beally's Syrah example, fruit that turns tarter on the palate points to an old world wine, and brettanomyces is typical of Northern Rhône Syrah, leading to a Northern Rhône conclusion
  • Beally rates vinification objective factors the most weakly correlated of the three types, because the greatest amount of choice in winemaking occurs during vinification and elevage
  • Structural clues such as high acid, high tannins or high alcohol, Beally writes, let him focus the palate evaluation on the tasting paradigms that match
  • McCamic describes observation-conclusion notes from her Master of Wine study: 14.5% alcohol and ripe, lush fruit leading to the conclusion that a wine is likely from a warm climate
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Exam Performance and Professional Application

Stamp wrote in Decanter (2013) that becoming a Master Sommelier means passing a test of three sections: tasting, practical service and theory. Wine Spectator (2018) describes the segments, each administered only once a year, as a 50-minute verbal theory exam, a practical exam involving a mock wine service, and a blind tasting of six wines in 25 minutes. Per Decanter's 2013 feature with Gerard Basset MW MS, the Court requires a 75% mark or better in each of the three sections, candidates never receive an official score, and the Court does not release past exam material. Ronan Sayburn MS told Decanter in 2013 that the 75% pass rate on the tasting means candidates "have to get five out of six wines pretty much exact." In October 2018 the board of the Court of Master Sommeliers Americas voided the results of its September 2018 deductive blind-tasting exam after receiving a report that a Master Sommelier had improperly disclosed information about the wines, invalidating the title for the 23 diploma recipients who had passed the tasting portion that year (Wine Spectator); six candidates who had passed the original exam passed again at the first re-sit, held on 5 December 2018 in St. Louis, Missouri (Decanter).

  • A sommelier cannot apply for the Master Sommelier programme but must be invited to study (Decanter, 2013)
  • Sayburn told Decanter in 2013 that passing all three exams in one sitting is extremely rare, and that candidates often pass one and then have three years to pass the rest
  • Head counts reported over time: 197 Master Sommeliers since the first exam in London in 1969 (Decanter, March 2013), 218 (Sayburn, Decanter, 2013), and 249 (Wine Spectator, October 2018)
  • Bjornholm (2016) recommended that 70% of tasting practice be six wines (three red, three white) timed to 25 minutes following the grid verbally; Beally instead favors comparative tastings over six-wine flights for improving deduction

The CMS Grid and the WSET Systematic Approach

WSET says its Systematic Approach to Tasting (SAT) is designed to build skills progressively through its qualification levels. The WSET Level 3 SAT for wine (2022, Issue 2) runs Appearance, Nose, Palate and Conclusions; where its entries are separated by a hyphen, students must select one and only one option. Its Conclusions heading is an assessment of quality, with a quality level from faulty through poor, acceptable, good and very good to outstanding, and a level of readiness for drinking or potential for ageing. Beally's deductive grid, by contrast, ends in a final conclusion on variety, origin, quality and vintage. McCamic notes that the Master of Wine program has no grid or required approach to tasting, while WSET and Court of Master Sommeliers exams are tied to a grid or systematic approach.

  • WSET Level 3 SAT (2022, Issue 2) alcohol scale: low, medium, high
  • WSET Level 3 SAT (2022, Issue 2) body scale: light, medium(-), medium, medium(+), full
  • WSET Level 3 SAT (2022, Issue 2) finish scale: short, medium(-), medium, medium(+), long
  • Gerard Basset MW MS told Decanter that both the Master Sommelier and Master of Wine qualifications test wine knowledge and tasting skills, but in a very different way

Sources and last verified

Primary sources: https://www.wsetglobal.com/media/11766/wset_l3wines_sat_en_may2022_issue2.pdf, https://www.wsetglobal.com/knowledge-centre/wset-systematic-approach-to-tasting-sat. Secondary sources: https://www.guildsomm.com/cfs-file/__key/communityserver-components-userfiles/00-00-00-66-84/preparing-for-deductive-tasting-exams-at-high-levels.pdf, https://www.guildsomm.com/public_content/features/articles/b/sbjornholm/posts/one-master-s-thoughts-on-how-to-prepare-for-the-advanced, https://www.guildsomm.com/public_content/features/articles/b/mary-margaret-mccamic/posts/blind-tasting-applications, https://www.guildsomm.com/learn/study/w/study-wiki/2683/tasting, https://www.decanter.com/premium/what-does-it-take-to-become-a-master-sommelier-246020/, https://www.decanter.com/learn/advice/master-of-wine-master-sommelier-difference-374802/, https://www.decanter.com/wine-news/three-make-it-through-latest-master-sommelier-round-14647/, https://www.winespectator.com/articles/questions-surrounding-blind-tasting-exam-leave-23-new-master-sommeliers-in-limbo, https://www.decanter.com/wine-news/six-new-master-sommeliers-after-tasting-exam-re-run-406392/. Last verified 2026-09-29

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Exam Study NotesWSET / CMS
  • Deductive versus recognition tasting: deductive tasting analyzes all of the clues before concluding; recognition tasting fixes on one clue and risks confirmation bias (Beally, GuildSomm).
  • Grid order in Beally's version: Sight, Nose, Structure, Palate, Initial Conclusion, Final Conclusion; he moved Structure ahead of Palate.
  • Initial Conclusion (Beally's grid): old world or new world, climate, possible varieties, possible countries, age range. Final Conclusion: variety or blend, country, region or appellation, quality or classification, vintage.
  • Master Sommelier tasting: six wines in 25 minutes (Wine Spectator, 2018); the Court requires 75% or better in each of the three sections (Decanter, 2013).
  • Objective factors (Beally): Varietal weighed strongest, Vineyard medium, Vinification least; decide the variety first, then the origin.

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