In my blog articles, I often refer to tasting as a quality control tool. However, to achieve reliable and reproducible results when tasting spirits, especially eaux-de-vie derived from fermented products, certain best practices must be followed.
From the tasting environment to sensory evaluation methods, here are some key recommendations for an optimal and rigorous analysis.

_Start by properly preparing your tasting

• Avoid tasting in the cellar, as ambient odors can alter perceptions. Opt for a neutral room and conduct the tasting at optimal times, such as before lunch.
• The olfactory analysis can be done at the natural alcohol strength of the spirit. However, it is recommended to dilute the spirit to around 40% ABV using the most neutral water possible. This enhances both olfactory and palate tasting performance.
  To achieve this, use a 50 ml or 100 ml test tube. The Labox “Alcohol adjustment” Boxette can help calculate the amount of water needed before topping up to 50 or 100 ml.
• Use straight-sided glasses, such as 125 ml INAO glasses. Ensure they are perfectly clean and free from residual odors (dish soap, limescale, dust).
• Rinse with hot water and let them air dry. Fill them to a maximum of one-third of their capacity.
• Mask the color if necessary. If the goal is to evaluate only the organoleptic properties (aromas and mouthfeel), it may be preferable to obscure the color of the spirit. Wrap the glass with opaque paper secured with a rubber band.
• Prepare a glass of the most neutral water possible.
• Do not swirl immediately. Let the glass sit for a few minutes to allow a gradient of aromas to form above the liquid. The lightest aromas (such as vanillin) can be detected a few centimeters above the glass.

• Take a few milliliters of liquid into your mouth and evaluate the perceived sensations:

a. Acidity: A sensation of freshness and liveliness.
b. Astringency: A feeling of dryness.
c. Sweetness: The perception of sugar or smoothness.
d. Bitterness: Ranges from mild to intense, depending on the spirit.
e. Perceived aromas: Identification of aromatic notes and their intensity, influenced by raw materials and the production process.
f. Aromatic persistence: The duration for which the aromas remain in the mouth after tasting (short, medium, or long finish).
g. Retro-olfaction: An olfactory phenomenon occurring after swallowing, as aromas travel back through the nasal passage, refining the perception of the spirit’s nuances.

• Bottom-of-the-glass olfaction: The olfactory step of the freshly emptied glass, which follows the palate phase, enhances retro-olfaction. This stage is important as it brings out the heavier organoleptic sensations, such as woody notes and rich rancio aromas (spices, aged floral notes). It can highlight the aromatic richness and complexity through the length of perception.

• Record these impressions on your tasting sheet.

_Other Technical Recommendations

• Effect of Tasting Order: The first spirits tasted influence the perception of subsequent ones. It is therefore recommended to start with the lighter ones, progressing from the lowest to the highest alcohol content to preserve the finesse of the aromas. It is also advisable to rinse the palate with a little water between tastings to avoid flavor saturation.
  • Comparative tests with a Reference Sample:
  When conducting comparative tests, both glasses should be prepared simultaneously to prevent variations due to oxidation or temperature changes.
  For a more objective analysis, it is recommended to prepare two identical reference glasses and one glass containing the sample to compare, or vice versa (triangular test). The goal is to identify which of the three is different.
  • Detection of Sulfur Compounds:
  If there is doubt about the presence of sulfur compounds (cabbage, egg, or burnt match odors), conduct a copper test:

– Place a small amount of clean, non-oxidized copper wool into a glass containing the spirit, while keeping a second reference glass without copper.
– Cover both glasses with a watch glass or a saucer and let them rest for a few minutes.
– Compare the aromas by first smelling the glass containing the copper, then the reference glass.

Technical Annexes

Annex 1 : Example of a tasting note recording sheet

Annex 2 : Suggested list of spirit colors

Annex 3 : List of aromas by category (non-exhaustive) and intensity rating guide

Annex 4 : List of major organoleptic defects (non-exhaustive)