Sources of Poor Quality are More Important than the Flaws
Sources of Poor Quality are More Important than the Flaws
They are Quality Flaws, but What is Their Source?
Discovering flaws and faults of poor quality spirits is important; however, their source is even more important. We can prevent flaws and faults by addressing their source. We may ask, “What’s that horrible smell? Flaws in odors may include descriptions such as nail polish, kerosene, tri-chlor, dead rodent, rotten eggs, and vomit. We cannot fix or avoid flaws and faults if their sources are unknown.
We will explore sources of certain poor quality flaws in the spirit. The discussion includes revulsive aromas and their possible causes. The cause of flaws in spirits is a complex subject. This presentation is a simple overview. Researchers have authored numerous books, in-depth studies, and journal articles on each of these poor quality problems. The NEAT glass helps identify poor quality flaws and their sources. flaws and their sources.
Raising awareness regarding the difficulties in producing high-quality spirits and to providing clues to the evaluator for recognition is important. Alan Gordon, CEO and co-founder of Aroma Academy supplied this material:
Discovering Poor Quality, Flaws, and Faults in Spirits
In developing flavor sensory skills, it is useful to categorize descriptors into two broad categories: Positive and Negative.
Understanding positive flavor attributes is vital for:
- product development, where companies are creating and developing interesting flavor profiles that differentiate them from the competition, and
- production quality control focuses on ensuring the consistency of flavor profile from batch to batch.
However, detecting and identifying negative flavor attributes (or ‘Faults’) is also fundamental in both these phases. This need is obvious in Spirits production. No company wants to produce faulty products for cost and reputational reasons. Therefore, early fault identification is vital. Perhaps less well understood is the fact that understanding Faults is also key in the creation and development phase as companies strive to develop robust products and processes that have the lowest probability of developing flavor Fault types.
What is a Fault and where do they come from?
Let us first take a step back and ask the question – What is a poor quality fault? Context determines the evaluation. A smoky note may be positive in one spirit type yet a fault in another if it does not fit the profile.
Part of the challenge in drinks development and production is that the potential sources of Faults are myriad and can be both internally and externally generated. Sources listed as;
- Raw Materials
- Processing
- Storage
- Maturation
- Degradation
- Contamination
A broad subset of Spirits Faults/Defects is common to wines and beers. In spirits, the additional potential areas such as distillation and longer-term cask maturation must also be considered as a source of poor quality. Faults in Spirits production, are related to internal processing or external and contamination related.
Processing: Poor Quality in Fermentation? Find the Source
Fermentation and the impact of defective or incorrectly processed raw materials or yeast can give rise to many fermentation-related issues. Although less high profile than in wine or beer, the impact of yeast type and processing is also significant in the flavor profile of spirits.
Established distillers develop their own bespoke in-house yeast of choice over many years called distiller’s yeast. Specialist yeast companies develop and produce distiller’s yeast. In each case, the objective is the same, which is to ensure consistency of output and avoid poor quality.
However, several producers – particularly craft distillers – are advocates of the use of wild yeast which can provide a multitude of different and varied flavor elements allowing increased brand differentiation – although this also provides the downside risk of more potential unpredictability with the danger of the creation of possible flavor faults. The wrong yeast can easily be the source of a flaw.
Potential faults that must be monitored, include the excess presence of acids such as isovaleric acid which makes its presence known with a distinct cheesy or even vomit type aroma/flavor note, or volatile phenols such as 4-ethylphenol providing aroma/flavor notes described as reminiscent of anything from leather to a barnyard!
Processing: Poor Quality in Distillation
Most people are familiar with the concept of the distillation cut where Spirits distillers aim to capture the heart of the distillation and eliminate the unwanted heads and tails. Distillers and QC staff must be trained to detect and identify the aromas/flavors of these unwanted elements and monitor for potential aromas/flavor faults. The head faults include excess acetaldehyde (with its volatile vaguely apple-like fruity aromas), acetone, methanol. Heads can also include ethyl acetate, with its classic solventy aroma.
Acetaldehyde
The unwanted heavier notes from the tails represent the final elements of the distillate low in ethanol and high in unwanted components. Accordingly, tails include alcohols such as butyl alcohol, amyl alcohol, and other elements such as furfural with its mix of flavor notes including almond and caramel.
Butanol
Another key element of the distillation process is the removal of excess sulfur compounds – typically by providing exposure to an appropriate level of copper. Excess sulfur can manifest itself in many ways in the aroma/flavor profile with unwanted notes ranging from excessive vegetable (such as overcooked cabbage) to garlic/onion-type notes or even burnt rubber.
Processing: Poor Quality in Maturation
Cask maturation creates additional opportunities for faults to develop. Fungi may contaminate the cask, or prolonged maturation may cause the spirit to extract excessive wood flavors. Too much vanilla character, for example, can overpower and unbalance the spirit’s overall flavor profile.
External Contamination
There are many sources of possible contamination from external sources, and we describe a couple of examples below. The quality and consistency of the water typically added to achieve a desired final ABV is often overlooked. Chlorine will distort or overpower the final flavor profile. Geosmin can provide an unwanted dominant earthy profile. The name Geosmin is based on Geo – earth and Osme – odor and typically has the aroma of damp soil.
Finally, we highlight is the issue of corked spirits. This is typically less of a poor quality problem in the world of Spirits as in Wine – where it has been a massive issue for decades. However, this fault also affects spirits sealed with cork closures. When chlorine—typically from a cleaning product—reacts with certain molds, the reaction can produce TCA (2,4,6-trichloroanisole). Although TCA commonly develops in corks, contaminated packaging, pallets, and other materials can also introduce it.
TCA
The resulting Fault is detected as a musty wet newspaper/damp cloth aroma/flavor which is not only unpleasant in its own right but also has the effect of attenuating the overall flavor profile. It should be noted that if this Fault finds its way into drinks production facilities it is notoriously difficult to eliminate.
Summary
Potential poor quality faults in spirits are many and varied and may appear from many possible sources. The list above describes only a few. Finding the source can help solve the problem.
Aroma Academy provides comprehensive sets of Faults Standards Kits and Sensory Faults Training to allow familiarization with typical drink Faults. In addition, we also facilitate the development of the necessary skills for their detection, identification, and articulation.
Identifying the fault allows evaluators to determine its source and take corrective and preventive action, whether the cause involves raw materials, processing, maturation, or external contamination.
Buyers, retail staff, professional bartenders, industry professionals, and a growing community of spirits enthusiasts benefit from understanding common fault types. Although this knowledge gives them greater insight into the world of spirits, it also strengthens their ability to evaluate quality. Detecting faults and flaws depends heavily on using properly designed diagnostic glassware, such as the NEAT glass.
