• Alcohol-based hand rubs formulated with technical-grade ethanol can increase exposure to alcoholic impurities. • Inexperienced manufacturers may introduce additional contaminants into the product. • More vigilant policing should be employed to ensure compliancy, safety and efficacy.

The COVID-19 pandemic led to panic-buying of alcohol-based hand rubs (ABHRs). In response, governmental agencies (e.g., Health Canada) permitted the sale of ABHRs formulated with “technical-grade” ethanol to alleviate the growing demand. Technical-grade ethanol contains elevated concentrations of impurities (e.g., acetaldehyde, etc.), which may exhibit dose-dependent toxicity. In this study, a rapid solvent extraction was employed to analyze gelled ABHRs via gas chromatography with flame ionization detection. In total, 26 liquid and 16 gelled ABHRs were analyzed for nine common impurities to determine compliance with Health Canada interim guidelines. Of 42 samples analyzed, 11 ABHRs appear to be non-compliant with interim Health Canada guidelines. Non-compliant ABHRs exhibited elevated concentrations of acetaldehyde, with a maximal concentration observed of 251 ± 10 µL L⁻¹; 3.3× higher than currently permitted. Nonetheless, frequent testing of ABHRs should be routinely conducted to reduce the risk of consumer exposure to non-compliant ABHRs.

The aroma-active compounds produced by Saccharomyces cerevisiae during the fermentation of wort are key to the unique aroma and flavour profiles of beer. In commercial fermentations, there is batch-to-batch variation depending on yeast “brewing fitness” or the health of the yeast, but how does yeast health impact fermentation performance and metabolite production during fermentation? To address this, daily samples were collected from three full-scale commercial fermentations. The specific gravity was measured immediately, and samples were collected for carbohydrate analysis by High-Performance Liquid Chromatography and volatile compound analysis by Head-Space Gas Chromatography Mass Spectrometry (HS-GC-MS). Acetate esters (3), medium-chain fatty acid ethyl esters (7), hop-derived compounds (3), and an off-flavour (1) were detected and identified, and their relative signal was recorded for each sample. While there did not appear to be an effect of generational age on the duration of fermentation, age, in terms of the number of generations from serial re-pitching, impacted the ratios of volatile compounds. This difference in ratios was observed as early as Day 2, resulting in a difference in the volatile compound profiles of finished beers, therefore resulting in inconsistency in the product. This is important knowledge for brewers as generational age must be considered when fermenting high-quality, consistent products and monitoring fermentation progress/duration may not be enough to determine the ability of yeast to produce balanced flavour profiles.