Volatile sulfur-containing compounds are important contributors to wine aroma. These compounds have low sensory thresholds and can impact wine flavor even at low concentrations. Sulfur-like off aromas (SLOs) can develop during anaerobic wine storage. There are many reports in the literature of wine stored under low-oxygen conditions developing "rotten egg" and "reduced" aromas, but the appearance of this condition in flavored wines due to interactions between the wine and flavoring agent has not been previously reported. Sixteen flavoring agents were evaluated for their ability to form SLOs following their addition to wine and bottle storage. After three months, wines spiked with one of the flavoring agents exhibited an SLO described as "skunky/burnt rubber." GC-Olfactometry was used to identify 3-methyl-2-buten-1-thiol (3MBT) as the compound responsible for the "skunky/burnt rubber" aroma. 3-methylbut-2-en-1-ol, a likely precursor of 3-MBT, was quantified by GC-TOF-MS and determined to be significantly higher in the odorous flavor.