TABLE 3 KEY FLAVOR MOLECULES ASSOCIATED WITH THE TWELVE STYLES OF BAIJIU Category Baijiu
bottling strength (40-50 percent ABV) will then be implemented, followed by careful blending and bottling (6, 8). Blends may finish out using 80-100 or more basic distillates (8).
So besides being a character in James Bond stories, who or what is Q or Qu? Qu is an
Nong Xiang Strong-aroma
Light-aroma (once classed as Fen-flavor)
Soy-sauce (Sauce aroma) (once classed as Maotai-flavor)
Key flavor molecules Ethyl esters: hexanoate, acetate, lactate, butyrate, valerate, heptanoate/ associated acids: hexanoic, butanoic (butyric), heptanoic plus furfural and phenylethyl alcohol Ethyl acetate, ethyl lactate, acetic acid, 2-methylpropanoic acid, β-damascenone plus terpenoids Ethyl hexanoate, hexanoic acid, 3-methylbutanoic acid, 3-methylbutanol, tetramethyl pyrazine, ethyl 2-phenylacetate, ethyl butyrate, ethyl acetate, 2-phenyethyl acetate, ethyl 3-phenyl propanoate, 4-methylguaiacol (phenolic compounds) & γ-decalactone. Syringic acid & amino acids
abbreviation for daqu — xiaoqu or β-phenethyl alcohol, ethyl acetate, ethyl lactate, ethyl-benzenecarboxylate, & Mi Xiang diethyl succinate jinqu (Qu, pron. “chew”) — meanSweet-honey or Rice Aroma ing molded cereals, and is a startTetramethyl pyrazine & 2-pentyl furan, heptanoic acid, ethyl heptanoate, Jian Xiang er culture (rich in bacterial, yeast, isoamyl acetate, 2-octanone, isobutyric acid, & butyric acid Complex (“Mixed”) aroma and fungal species and nutrients) Ethyl pentanoate, ethyl hexanoate, 3-methylbutanal, methional, ethyl butaZhima Xiang and a substrate complex used to noate, 3-methyl-1butanol, hexanoic acid, butanoic acid, trimethyl pyrazine Sesame aroma/ 2-acetylfuran, ethyl furoate & methionol initiate fermentations for Chinese Roasted-sesame-like liquor production (8, 12, 16), the Butyric acid, ethyl hexanoate, caproic acid, dimethyl trisulfide, ethyl butaYao Xiang constituents being regarded as sacnoate, 2-phenethyl alcohol, 3-methyl butyrate, 4-methyl phenol, 4-methyl Herbal — Chinese herb-like guaiacol, β-damascenone, ethyl pentanoate, (E,Z)-2,6-nondienal, borneol, & charifying and fermenting agents. (Medicine aroma) fenchol. High total acids Several different types of daqu are Feng Xiang used, each having different flavors Ethyl acetate, ethyl caproate, & isoamyl alcohol Fengxiang (“Phoenix”) — — light, strong, or sauce flavor aroma for example (16). The flavor notes Esters (ethyl acetate, lactate, ethyl hexyl acetate, ethyl butyrate, palmitic ester), Laobaigan Xiang are associated with the metabolic alcohols, aldehydes, acids (linolenic acid), ketones, hydrocarbons, pyrazines, Laobaigan or Laobaiganxiang activities of the types of microaromatics, & phenolic compounds. Fuselly with high level isoamyl alcohol — aroma organisms found for each type of (E)-2-octenal, 2-phenylethanol, 3-(methylthio)-1-propanol (methional), daqu (6). Daqu contains cereals, diethyl 1,7 heptanedioate (diethyl pimelate), diethyl 1,8-octanedioate (diethyl peas (see below), a mixed microChi Xiang suberate) & diethyl 1,9-nonanedioate (diethyl azelate). (E)-2-nonenal — Chixiang — Chi aroma flora of fungi and bacteria, various noted in beer as a staling aldehyde + other fatty aldehyde derivatives and microbial enzymes and resultant components. metabolites and key flavor notes Te Xiang that contribute to the aromas of 98+% esters and alcohols — especially ethyl acetate, caproate & heptylate Te - Texiang — (“Special”) aroma the final distillates. During heating processes daqu also contributes Acids, alcohols, ethyl acetate, ethyl caproate, ethyl butanoate plus low level of Fuyu Xiang Maillard reaction flavors (complexethyl lactate. Fuyu-aroma ity of chemistry in action for flavor See Table 2 for general details of each type/style plus production methods and overall flavor characteristic. The production). We likely are missing chemical components — as classes — giving rise to the general flavor descriptors (acids, esters, sulfur compounds, etc.) some details simply because many appears in the body text and will be further outlined in another forthcoming Artisan Spirit article. Many research publications present discussions on the identified flavor components and their descriptors (4, 6, 7, 10, 21). Note: Fuyu papers on the topic are in Chinese. Xiang was noted in the footnotes to Table 2 — only 11 styles covered in the body of that table. However, dozens of scientific papers and reviews are in English and trolled incubation of the paste whereby it becomes inoculated with could be sources of valuable insight for those wishing to dabble the multiple species of indigenous microorganisms. These bacteria, in qu production or for those wishing to understand the complex yeast strains, and molds provide the catalytic/enzymatic powers to microbiology of baijiu production. affect the manifold biochemical reactions needed to convert the Get in the Right Q for Baijiu. As implied above, baijiu and baijiu raw materials into the desired and subtly different flavor components — and, of course, the requisite amount of alcohol. other Chinese spirits and alcohol-containing beverages would not (6, 8, 16) be possible without qu. However, three types of qu should be conThe three types of qu for baijiu production are known as big qu, sidered here. Qu, itself a fermented product, is made from starchy/ small qu and bran qu, though there are other types of qu for making grain materials via the moistening of crushed grains and the con-
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