title: Heavy and light beer: a carbon isotope approach to detect C(4) carbon in beers of different origins, styles, and prices.
abstract: The carbon isotope ratios (delta(13)C) of 160 beers from around the world ranged from -27.3 to -14.9 per thousand, primarily due to variation in the percentage of C(3) or C(4) plant carbon in the final product. Thirty-one percent of beers had a carbon signature of C(3) plants (barley, rice, etc.), whereas the remaining 69% contained some C(3)-C(4) mixture (mean of mixtures, 39 +/- 11% C(4) carbon). Use of C(4) carbon (corn, cane sugar, etc.) was not confined to beers from any particular region (Pacific Rim, Mexico, Brazil, Europe, Canada, and the United States). However, the delta(13)C of European beers indicated mostly C(3) plant carbon. In contrast, U.S. and Canadian beers contained either only C(3) or C(3)-C(4) mixtures; Brazilian, Mexican, and Pacific Rim beers were mostly C(3)-C(4) mixtures. Among different lagers, U.S.-style lagers generally contained more C(4) carbon than did imported pilsners. Among different ales, those brewed by large high-production breweries contained significant proportions of C(4) carbon, while C(4) carbon was not detected in microbrewery or home-brew ales. Furthermore, inexpensive beers generally contained more C(4) carbon than expensive beers.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA. Brooks.ReneeJ@epa.gov
authors.forename: J Renée
authors.initials: JR
authors.lastname: Brooks
authors.forename: Nina
authors.initials: N
authors.lastname: Buchmann
authors.forename: Sue
authors.initials: S
authors.lastname: Phillips
authors.forename: Bruce
authors.initials: B
authors.lastname: Ehleringer
authors.forename: R David
authors.initials: RD
authors.lastname: Evans
authors.forename: Mike
authors.initials: M
authors.lastname: Lott
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Martinelli
authors.forename: William T
authors.initials: WT
authors.lastname: Pockman
authors.forename: Darren
authors.initials: D
authors.lastname: Sandquist
authors.forename: Jed P
authors.initials: JP
authors.lastname: Sparks
authors.forename: Lynda
authors.initials: L
authors.lastname: Sperry
authors.forename: Dave
authors.initials: D
authors.lastname: Williams
authors.forename: James R
authors.initials: JR
authors.lastname: Ehleringer
mesh_terms: D001515:Beer / Q000032:analysis* / Q000145:classification; D001938:Brazil; D002244:Carbon / Q000032:analysis* / Q000737:chemistry; D002247:Carbon Isotopes; D005060:Europe; D005511:Food Handling; D008800:Mexico; D014481:United States
chemical_list: D002247:Carbon Isotopes; D002244:Carbon