First Study of Sourdough Beer Aging Via the Chemical Fingerprint of Volatile Markers

Abstract

Despite years of research, sensory worsening during beer aging remains a challenge to brewing chemists. Taking into account the novelty of sourdough beer and the interest of consumers in artisanal and specialty beer, the study of its aging is mandatory. The shelf life of Lambic beer is known to be much longer than that of common beer, and it may last over a span of several years. No study is available for the shelf life of sourdough beer whose recipe is inspired to Lambic beer production. For this reason, it would be useful to establish a dataset of relevant substances for the objective evaluation of sourdough beer aging, with and without refermentation in the bottle, in a 2-year endpoint study. In our work, the headspace solid-phase microextraction was used to sample the volatile profile of fresh and aged samples. Principal component analysis enabled (i) the selection of the most eligible aging volatile indicators and (ii) the clustering of the samples according to their aging and fermentation process. Sourdough non-refermented beers have a shorter shelf life than others assessed in the study. Sourdough refermented beers still have to be analytically and sensorially monitored in the years to come to detect their very long shelf life.