The Chemical Fingerprint of Beer from a Single Experiment with Minimum Sample Preparation – A Rapid Quantitive Analysis by 1H NMR Spectroscopy

NMR Spectroscopy is the premier tool utilized by chemists to obtain detailed chemical information on molecular structure and is used extensively in molecular structure verification, chemical purity analysis, and complex mixture analysis. We have developed a quantitative NMR analysis that yields a chemical fingerprint that brewers can utilize to follow detailed variations in the chemistry observed in the various stages of the brewing process (malting, mashing, boiling, fermentation, ageing, and blending). The analysis observes all molecules in the beer at the same time and each molecular component (acids, alcohols, amino acids, malt-oligosaccharides) yields a unique spectral fingerprint pattern that is related to the structure of the molecule. Though the spectrum consists of a large number of overlapped individual fingerprints it is possible to identify and quantify individual components because many components have signals that appear at unique and specific points in the spectrum. The quantitative analysis is performed by comparing the area under the individual molecule signals to that of an internal standard (Maleic Acid 99%). Molecular components are quantified on a weight/volume basis in mg/L (parts-per million). Ethanol is also quantified on a %volume/volume basis. The technique is not only applicable to the brewing process but is also being…

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Beer and Cider Analysis – Example of Spectral Repeatability of Benchtop 60 MHz NMR System

Here is an example of spectral reproducibility. We are doing a lot of beer NMR at the moment on our 300 MHz NMR and for "giggles" we are running many samples through the various bench-top systems in our lab. We have been quantifying small organic acids (lactic, acetic, succinic , malic, citric, etc.) as they can give some idea of yeast activities and health during fermentation. We are also quantifying  and studying the 1,4/1,6 linkage distribution of residual dextrins. The series of superimposed spectra below consists of 28 spectra of a freeze dried beer sample (a unique Belgian Dubbel. Each spectrum was 128 pulses and took approximately 30 minutes per spectrum. So the superimposed data represents a 14 hour continuous stability test.The data was automatically processed with 16K zero-fill and autophase.It looks pretty damn good.   We've been looking at a lot of sour beers - here is a home-brewed Flemish Red aged in an oak barrel - note the high lactic and acetic content. We've also been analyzing a lot of hard ciders - commercial and home-brewed varitieties of various styles - very different from one sample to another in the small molecule and sugar chemistry.     1H…

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From Atoms to Flavour: The Chemistry of Beer

Adam DiCaprio (ex PNA) gave an excellent Science Cafe Talk under the auspices of the ACS North Carolina Section at the Busy Bee Cafe in downtown Raleigh on December 2, 2014. CHanging gears from his previous talks he centered the discussion on malt and hop chemistry as well as an start-to-finish NMR analysis of production runs of a bottled commercial tavern ale. If you are interested in having Adam give a detailed chemistry seminar on beer at your section meetings please contact him directly at adam@process-nmr.com. A PDF version of his talk is available here .... ACS Science Cafe Talk - Dicaprio - Busy Bee Cafe - Raleigh NC - 12-2-14

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