Aroma of Shochu

Where Does Shochu Aroma Come From?

The aromas created by shochu are a result of when various elements from the originating base materials are converted into aromatic compounds during certain steps of the production process.

Compounds that Create the Unique Aroma of Shochu

Character	Chemical Compound	How it is Produced	Shochu
Violet	β-Ionone	Orange sweet potatoes - may be derived from β-carotene.	Sweet Potato Shochu
Smoky	Guaiacol	Sweet potatoes.	Sweet Potato Shochu
Yogurt/Butter	Diacetyl	Purple sweet potatoes.	Sweet Potato Shochu
Mushroom	1-Octen-3-ol	Koji: Mainly produced by black koji.	Awamori
Banana	Isoamyl acetate	Fermentation: Mainly produced by yeast.	All
Apple	Ethyl caproate	Fermentation: Mainly produced by yeast.	All
Pineapple	Ethyl isobutyrate	Fermentation: Mainly produced by yeast.	All
Nail Polish	Ethyl acetate	Fermentation: Mainly produced by yeast.	All
Floral	Rose oxide	Fermentation & Distillation: An acid catalyst converts citronellol to rose oxide (sweet potato shochu).	Sweet Potato Shochu
Rose	β-Phenetyl alcohol	Fermentation: Production in association with the metabolism of phenylalanine in yeast.	All
Lavendar	Linalool	Fermentation & Distillation: Koji enzymes decompose monoterpene glycosides in sweet potatoes. Acid and heat during distillation further convert it to linalool (sweet potato shochu).	Sweet Potato Shochu
Spicy	4-Vinylguaiacol(4-VG)	Fermentation & Distillation: Koji enzymes isolate and decarboxylate ferulic acid derived from raw materials. It is also produced by heat during the distillation process.	All
Sulfur	S-Methyl thioacetate	In beer, yeast is known to be produced from methanethiol and methionine.	All
Pickled Japanese White Radish	Dimethyl trisulfide (DMTS)	Fermentation: Production may be related to sulfur-containing amino acids in the mash.	Awamori
Vinegar	Acetic acid	Fermentation: Mainly produced by yeast.	Brown Sugar Shochu
Green	Acetaldehyde	Fermentation & Distillation: Produced from amino acids either by yeast or heat during distillation.	All
Pungent	Isovaleraldehyde	Fermentation & Distillation: Produced from leucine by the yeast metabolism during fermentation. It is also believed to be a product of Strecker degradation by heat during distillation.	All
Ink	Isoamyl alcohol	Fermentation: Produced in association with yeast leucine metabolism.	All
Resin	Caprylic acid	Fermentation: An intermediate in the yeast fatty acid synthesis pathway of yeast.	All
Oily/Soapy	Ethyl laurate	Fermentation: Lipids from raw materials are decomposed by enzymes and combined with ethanol to produce ethyl laurate. It is also produced during aging.	Awamori
Honey, Elderflower	β-Damascenone	Distillation: Mostly believed to be produced later in the distillation process. The characteristic aroma of sweet potato shochu.	Sweet Potato Shochu
Vanilla	Vanillin	Fermentation, Distillation & Aging: Hemicellulose in rice converted by koji enzymes, yeast enzymes, heat in distillation, and long-term aging. It is also widely found in barrel aged alcoholic drinks.	Awamori, Barrel Aged Shochu
Caramel	Sotolon	Aging: Produced during the aging of awamori in earthenware pots.	Awamori
Coconut	Whiskey lactone	Aging: A characteristic aroma of oak barrel aging and is a result of aging in barrels.	Barrel Aged Shochu
Coffee	2-Furanmethanthiol	Distillation: Generally produced in the heating process and/or transferred from roasted raw materials.	All
Nutty	2-Ethyl-3,5- dimethylpyrazine	Distillation: Produced in the heating process and often found in barley and brown sugar shochu.	Barley Shochu, Brown Sugar Shochu
Smokey	Furfural	Distillation: Produced by heating sugars under low pH conditions during distillation, and often found in the tail.	All
Cheese	Butyric acid	Contamination: Produced when the mash is contaminated by bacteria.	-
Grass	Hexanal	Raw material/Distillation/Aging: Produced by the decomposition of long-chain fatty acids such as linoleic acid.	All
Mold	2,4,6-Trichloroanisole (TCA)	Contamination: When chlorine-based disinfectants are used for wooden equipment, the precursor is generated and mold converts it to TCA.	-