Distilled beverage aging: A review on aroma characteristics, maturation mechanisms, and artificial aging techniques

Abstract

The market value of distilled beverage relies on its quality with a major contribution of distinctive and fascinating aromas. The aroma of distilled beverage is built on the basis of chemical components and can be modified through a series of physical and chemical processes such as aging. Revealing the hidden knowledge behind the evolution of numerous chemical components during these physicochemical processes in distilled beverages is not only significant but also challenging due to its complex system. In this review, the trends in the changes of associated aroma compounds over aging are proposed on the basis of understanding the relationship between chemical components and aroma profiles of numerous typical distilled beverages. The different aging systems, both classical platforms from Eastern countries (pottery jars) to Western countries (wood barrels), and modern platforms such as artificial aging technologies are outlined and compared with their respective applications. Optimizing aging processes is a challenging but imperative step, which warrants further fundamental knowledge from targeting aging‐related molecules to the exploration of multitude physicochemical reaction mechanisms that occur during this process, such as the formation of potent odorant compounds in specific containers and environments, as well as mass transfer processes between solid and liquid interfaces. Understanding these maturation mechanisms of distilled beverages expressed by chemosensory signature holds promise for major improvements in future aging technologies that can efficiently yield stable and high‐quality products.

Provocation: prolonged maturation of beer is of unproven benefit

“…Thus changes to sulphur compounds in whisky such as 3-(methythio) propanal, dihydro-2-methyl-3(2H) thiophenone, ethyl 3-(methylthio)propanoate, 3-(methylthio) propyl acetate, 3-(methylthio) propanol, DMS, dimethyl disulfide (DMDS), DMTS, 2-thiophenecarboxaldehyde, 5-methyl-2-thiophenecarboxaldehyde, benezothiophene, and benzothiazole occur over a timescale of years (usually at least three) rather than weeks or a few months (Masuda andNishimura, 1982, Wanikawa andSugimoto, 2022). Wang et al (2023) have recently published a review of the changes occurring during the ageing of several distilled beverages. Amongst the chemical species reported to change during maturation (without directly invoking materials derived from or lost to wood) are (a) increased levels of organic acids; (b) an increase followed by a decrease in alcohols; (c) an increase in the levels of aldehydes; (d) an increase in the level of esters, followed by a decrease; (e) an increase in the level of furans, such as furfural; (f) an increase in the level of ketones; (g) an increase in pyrazines; (h) a decrease in sulphurcontaining substances and (i) an increase in terpenes and norisoprenoids.…”

Distribution and Sensory Impact of (2E,4E,6Z)-nonatrienal and Trans-4,5-epoxy-(E)-2-decenal in Wines and Spirits

“…16,17 In addition, slower chemical reactions may occur, such as oxidation, hydrolysis, esterification, and condensation. 4 All of these reactions induced by wood aging lead to a wide range of volatile compounds that underpin the sensory identity of alcoholic beverages aged in contact with wood. Oak lactones, volatile phenols, phenolic and furanic aldehydes, and thiols are the most significant aromatic compounds that may influence the aroma of these beverages.…”

“…It is now widely accepted that oak wood-derived compounds affect the aroma, the taste, and even the color of wines and spirits. − Their presence improves their quality, contributing richness and enhancing stability and complexity . In wine, complex mechanisms associated with the solubilization of volatile and nonvolatile compounds , and their biotransformation by microorganisms , concomitant with oxygen ingress through the wood are fundamental in the final aroma balance. , Similar chemical mechanisms occur in spirits due to years of barrel aging, the loss by volatilization of easily volatile compounds, as well as the reaction of ethanol with compounds extracted from oak wood (acetalization). , In addition, slower chemical reactions may occur, such as oxidation, hydrolysis, esterification, and condensation …”

“…According to the beverage, these compounds may be produced specifically or indifferently during the various stages of production: from the raw material (grape, cereal, cane sugar) to the wine or spirit. Aromas have six different origins: Raw material-derived compounds including monoterpenes, norisoprenoids, methoxypyrazines, thiols, and lactones; Fermentation (yeast, bacteria)-derived compounds formed from sugar (hexoses and pentoses), organic acid, and fatty acid metabolism, which give esters, alcohols, organic acids, aldehydes, ketones, and lactones; Distillation-derived compounds (for spirits), such as Maillard-derived compounds, esters, alcohols, and volatile fatty acids, obtained by heating and concentration (a feature of spirits); Oak wood compounds extracted during maturation; Oak wood-derived compounds resulting from transformations occurring thanks to yeast and bacteria metabolism, enzymatic reactions, and slow chemical reactions in alcoholic and acidic conditions; Formation/degradation of compounds by complex chemical mechanisms linked mainly with oxidation and the acidic conditions of the beverage. …”

Characterization of Key Aging Aroma Compounds in Aged Jiangxiangxing Baijiu and Their Formation Influencing Factors during the Storge Process

“…The aging process is the most important factor in improving the flavor quality of distilled liquor after fermentation and distillation. 1 Using pottery jars for storage is unique to Baijiu (Chinese liquor), which is completely different from using oak barrels. It is empirically believed that various physicochemical changes occur during this storage process, including volatilization, adsorption, 2 oxidation, 3 hydrolysis, esterification, 4 polymerization, 1 etc.…”