A Drink Is A Drink? Variation in the Amount of Alcohol Contained in Beer, Wine and Spirits Drinks in a US Methodological Sample William C. Kerr, Thomas K. Greenfield, Jennifer Tujague, and Stephan E. Brown Background: Empirically based estimates of the mean alcohol content of beer, wine and spirits drinks from a national sample of US drinkers are not currently available. Methods: A sample of 310 drinkers from the 2000 National Alcohol Survey were re-contacted to participate in a telephone survey with specific questions about the drinks they consume. Subjects were instructed to prepare their usual drink of each beverage at home and to measure each alcoholic beverage and other ingredients with a provided beaker. Information on the brand or type of each beverage was used to specify the percentage of alcohol. Results: The weighted mean alcohol content of respondents’ drinks was 0.67 ounces overall, 0.56 ounces for beer, 0.66 ounces for wine and 0.89 ounces for spirits. Spirits and wine drink contents were particularly variable with many high-alcohol drinks observed. Conclusions: While the 0.6-ounce of alcohol drink standard appears to be a reasonable single standard, it cannot capture the substantial variation evident in this sample and it underestimates average wine and spirits ethanol content. Direct measurement or beverage-specific mean ethanol content estimates would improve the precision of survey alcohol assessment. Key Words: Beer, Wine, Spirits, Standard Drink, Methodology I N THE UNITED STATES, both the government and the alcoholic beverage industry usually define a standard drink as having the equivalent of 0.6 ounces (17.74 ml or 14 g) of pure alcohol (U.S. Department of Agriculture, 2005). While the liquid volume of each beverage amounting to this standard will vary depending on the percentage alcohol by volume (%ABV), the commonly given standard sizes are 12 ounces (355 ml) of beer, 5 ounces (148 ml) of wine and 1.5 ounces (44.4 ml) of spirits. The governments of other countries and many researchers define a variety of standard sizes ranging from 8 to 10 g in the UK and Australia to 23.5 g in Japan (Turner, 1990). Even the formulas for converting ounces of ethanol into to milliliters and grams suffer from confusion due to differing sizes of US and UK fluid ounces, differing estimates of the density of ethanol relative to water and the compounding of round- ing effects (Miller et al., 1991). In surveys of alcoholic beverage consumption partici- pants are typically queried on the number of standard drinks they usually consume or have consumed during a specified reference period such as the past 30 days or 12 months (Greenfield, 2000). In some cases, respondents are given a definition of this standard drink, for example the 0.6 ounce of ethanol equivalent sizes, while in other cases no definitions are given. Regardless of what they are told constitutes a standard drink, many respondents are likely to report their number of drinks in terms of the drink size they actually consume (Kaskutas and Graves, 2000). Surpris- ingly little research has attempted to measure and docu- ment the mean, distribution and sources of variation in the alcohol content of drinks in the US population. Variation in drink size appears to be considerable, particularly for spirits and wine, with implications for virtually all aspects of alcohol research and for consumer behavior in regards to conforming to safe drinking limits and avoiding problems such as driving under the influence (DUI) of alcohol as defined by state blood alcohol concentration (BAC) limits. A number of studies in the US and other countries have considered variations in the size and strength of wine, beer and spirits drinks and their importance in standard drink assessment. White et al. (2003) found that subjects poured larger than standard spirits and beer drinks in a sample of 106 US college students. In a sample of 329 largely African- From Alcohol Research Group, Public Health Institute (WCK, TKG, JT, SEB), Berkeley, CA; and University of California, San Francisco (WCK, TKG), San Francisco, CA. Received for publication March 11, 2005; accepted August 9, 2005. This research was supported by grants P-50-A05595 and R21-AA-13532 to the Alcohol Research Group, Public Health Institute from the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Reprint requests and correspondence: Alcohol Research Group, 2000 Hearst Ave., Suite 300, Berkeley, CA 94709-2130; Fax: (510) 642-7175; E-mail: wkerr@arg.org Copyright © 2005 by the Research Society on Alcoholism. DOI: 10.1097/01.alc.0000187596.92804.bd 0145-6008/05/29011-2015$03.00/0 ALCOHOLISM:CLINICAL AND EXPERIMENTAL RESEARCH Vol. 29, No. 11 November 2005 Alcohol Clin Exp Res, Vol 29, No 11, 2005: pp 2015–2021 2015