Understanding the Chemistry Behind Whisky Flavor

A recent study exposed how analytical techniques can be used to differentiate between different types of whiskey. Through the use of techniques such as comprehensive two-dimensional gas chromatography (GC×GC), solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC–MS), and high-performance liquid chromatography (HPLC), a team of researchers from the China National Research Institute of Food and Fermentation Industries studied the chemistry of Chinese whiskies. By doing so, they were able to show through chromatography how locally sourced raw materials, such as Qingke barley and Mongolian oak barrels, shape the aroma, flavor, and mouthfeel of Chinese whiskey (1). The findings of this study were published in the journal Food Chemistry (1).

Why were GC×GC, HPLC, and SPME-GC–MS used in this study?

The researchers selected these techniques in their study because they determined that all three could be used to offer a more comprehensive look into the chemistry of whiskies. The researchers wanted to compile qualitative and quantitative insights into the complex mixture of volatile and phenolic compounds contributing to whisky aroma, flavor, and mouthfeel. These techniques helped them accomplish this objective.

As part of the experimental procedure, the team collected 15 whiskey samples, making sure that the samples were regionally variable. Scotch malt whiskies from Scotland, American Bourbons, and Chinese whiskies from provinces such as Sichuan, Yunnan, Fujian, Hunan, Taiwan, and Qinghai were all included in the sample subset (1). The different origins of the whiskies helped provide a broad spectrum of production conditions, climates, and raw materials (1).

What were the findings of the study?

The researchers found that by using GC×GC, HPLC, and SPME-GC–MS, they were able to determine how Qingke barley, a highland grain mostly cultivated in Qinghai and Tibet that is used in whisky production, influenced the chemistry of Chinese whiskeys. The research showed that Qingke barley imparts unique volatile and phenolic compounds not found in traditional malt whiskies. These compounds enhanced aromatic complexity, offering floral and fruity notes layered with subtle spice (1). This profile differs from Scottish whiskies, which have more malty qualities (1).

The study also uncovered findings about Mongolian oak. This wood is normally used for Chinese distillers for barrel aging (1). Unlike American white oak or European oak, Mongolian oak was found to release distinct polyphenols and lignin-derived aromatic compounds into the whisky during maturation (1). These contributed to richer tannic structures and deeper aromatic layers, including hints of resin, herbs, and toasted wood, creating a bolder sensory profile compared to the vanilla and caramel notes associated with American Bourbon barrels (1).

This discovery is important because barrel selection plays a key role in developing whiskey flavor. By incorporating Mongolian oak, Chinese distillers may be carving out a signature maturation process that differentiates their products within an industry often dominated by established Western traditions (1).

What are the limitations of this study?

Although the use of GC×GC, HPLC, and SPME-GC–MS proved to be effective, the researchers caution that their findings should be taken lightly. First of all, the sample size used for this study was only 15 whiskeys. Although they came from different regions, this compilation was still very small. Future studies, the researchers explain, should expand the sample size and explore additional variables, including fermentation methods, climate-driven aging processes, and longer-term maturation effects (1).

What do the findings of this study mean for future work?

Whiskey demand is expected to grow. According to Grand View Research, whiskey exports and revenue generated are set to increase from 84.06 billion in 2024 to 114.26 billion by 2030 (2). Chinese brewers are looking to capitalize on this growing market by differentiating their products from the Scottish and American ones. The researchers demonstrated through this study that chromatographic techniques can help show that, through the deliberate use of native barley and oak, Chinese distillers can differentiate their products while creating an entirely new flavor category in the world of spirits (1).

References

1. Yang, Y.; Gao, M.; Song, X.; Wang, D. Exploration and Characterization of Flavor Compounds in Chinese Whiskies: Qingke Whisky and Mongolian Oak Barrel Aging via GC×GC and Multivariate Analysis. Food Chem. 2025, 485, 144394. DOI: 10.1016/j.foodchem.2025.144394
2. Grand View Research, Whiskey Market Size, Share & Trends Analysis Report By Product (Malt, Wheat, Rye, Corn, Blended, Others), By Quality (Premium, High-End Premium, Super Premium), By Region, And Segment Forecasts, 2025 – 2030. Grand View Research. Available at: https://www.grandviewresearch.com/industry-analysis/whiskey-market (accessed 2025-08-29).