Saku-echi shū・sakusan-echiru shū
- Ethyl acetate smell
Ethyl acetate is an ester, and its aromatics contribute to the pleasant aroma of sake. It is produced by sake yeast, but, if present in too high a concentration, can give an impression like nail-polish remover or adhesive. (In sake industry slang, this off-odour is often referred to by the name “Cemedine (セメダイン) smell” after a Japanese glue manufacturer. ) Primary causes are thought to include the following.
- In cases where ginjo-shu is treated heavily with active carbon, the aromatic balance may be disturbed, making ethyl acetate stand out. Further, certain strains amongst the ginjo yeasts which produce high levels of fragrance may produce high levels of the substance under certain conditions.
- It may be produced when moromi is contaminated by film-forming wild yeasts. (Called sanmaku (産膜) yeast in Japanese, these form a membrane when propagated in a liquid medium.)
- When fermentation control is poor or the mash temperature is low, large quantities may be produced.
With proper care, ethyl acetate may be a beneficial contributing component to sake aroma.