Skip to main content

Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image

Polyelectrolyte titration of whisky

Abstract

Polyelectrolyte titration using a fluorescent indicator was applied to determine the electrolytic charges in 10 whiskies at various pH levels. Tannic acid was also titrated to compare the relation between pH and charge because the polyelectrolytes in whisky were postulated to be polyphenols, mainly tannic acid, which are gradually extracted from a wood cask over the years. Below pH 7, the pH-charge curves for whisky were analogous to those for tannic acid, indicating that carboxyl groups in tannic acid were fairly stable on maturation of the whisky. The charge of the tannic acid increased with increasing pH, whereas that of whisky had a tendency to level off. The degree of leveling off was higher for whiskies with longer maturation. These phenomena are believed to be due to the oxidation of pyrogallol and catechol moieties in tannic acid, which occurs during storage of the whisky. There was a clear tendency for the whiskies with higher prices to have higher charges, that is, a higher tannic acid content.

References

  1. 1.

    Nishi N, Saita M (1994) Cluster in whisky. Chem Chem Ind 47:168–171

    Google Scholar 

  2. 2.

    Koga K (1979) Physico-chemical properties of aqueous solutions of ethanol and alcholic beverages. Nippon Shokuhin Kogyo Gakkaishi 26:311–324

    CAS  Article  Google Scholar 

  3. 3.

    Sato K, Nakatsubo F, Murakami K, Hattori T (1992) Sugar components in malt whisky. I. Analysis by gas chromatography Mokuzai akkaishi 38:608–611

    CAS  Google Scholar 

  4. 4.

    Sato K, Nakatsubo F, Kawamoto H, Murakami K (1992) Sugar components in malt whisky. II. Liberation of monosaccharides during one year maturation. Mokuzai Gakkaishi 38:880–883

    CAS  Google Scholar 

  5. 5.

    Sato K, Nakatsubo F, Kawamoto H, Murakami K (1994) Sugar components in malt whisky. III. Liberation of monosaccharides and tannins during three years maturation. Mokuzai Gakkaishi 40:846–852

    CAS  Google Scholar 

  6. 6.

    Tanaka H, Sakamoto Y (1993) Polyelectrolyte titration using fluorescent indicator. I. Direct titration of anionic and cationic polyelectrolytes with 10−4N standard solutions. J Polym Sci Chem 31:2687–2691

    CAS  Article  Google Scholar 

  7. 7.

    Tanaka H, Sakamoto Y (1993) Polyelectrolyte titration using fluorescent indicator. II. Analysis of cationic starches and flocculants. J Polym Sci Chem 31:2693–2696

    CAS  Article  Google Scholar 

  8. 8.

    Senju R (1953) Untersuchung uber Lignin und Zellstoff. I. Eine neue Bestimmungsmethode von Ligninsulfosaure in Sulfitablauge durch Kolloidtitration. Bull Chem Soc Jpn 8:143–147

    Google Scholar 

  9. 9.

    Senju R (1969) Koroido Tekitei Ho, Nankodo, Tokyo

    Google Scholar 

  10. 10.

    Wassmer K, Schroeder U, Horn D (1991) Characterization and detection of polyanions by direct polyelectrolyte titration. Makromol Chem 192:553–565

    CAS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Hiroo Tanaka.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Tanaka, H., Tsukada, T., Ichiura, H. et al. Polyelectrolyte titration of whisky. J Wood Sci 46, 172–174 (2000). https://doi.org/10.1007/BF00777367

Download citation

Key words

  • Whisky
  • Wood cask
  • Polyphenol
  • Tannic acid
  • Polyelectrolyte titration