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Hops and Hop Products

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Substances of importance for beer

  • Bitter substances
  • Oils
  • Polyphenols
  • Protein
  • Minerals


A good beer needs a good aroma and acceptable palate and a great deal of that flavour in beer is provided by hops. It has been said: "Malt is the soul of beer and yeast gives it life but the kiss of the hop is the consummation of that life. "The lupulin glands of the female flower cones of the hop plant provide the different bitter substances which are the basis for beer bittering. Hop cones or hop extracts are added during the wort boiling where the largely insoluble a-acids (humulones) from the hops are isomerized to the more soluble iso-a-acids, the main bittering substances found in beer. Hops also contain -acids (lupulones), which are claimed to add bitterness to beer, especially after oxidation. Analysis of the hop acids in hop products is important for quality control. The analysis is performed by HPLC (High Pressure Liquid Chromatography) using a reverse phase C18 column especially developed for this purpose, and elution with acidic, aqueous methanol.

acidconv.gif (12680 bytes)Conversion of a-acids to iso-a-acids.

hopshplc.gif (18079 bytes)HPLC analysis of hops.



This page was last updated 06/08/99. Send comments to