Why the spice cabinet could secretly store more bacteria than you think

Spice jars are among the top germ-ridden surface in the kitchen, according to a recent study.

The study, commissioned by the Department of Agriculture's Food Safety and Inspection Service, looked to determine the prevalence and degree of cross-contamination over a variety of kitchen surfaces during meal preparation.

Researchers observed 371 people, who were all instructed to season and cook with raw, ground turkey patties that contained a harmless tracer virus called MS2 in kitchen settings of various sizes.

Overall, 48% of spice containers that were sampled showed evidence of the bacteria from the turkey, indicating MS2 cross-contamination. According to the findings, spice containers had the highest MS2 concentrations across kitchen surfaces, making them a key vehicle for cross-contamination.

After the directed meal was prepared, 12 areas throughout the kitchen were swabbed for testing, including kitchen utensils, cleaning areas, kitchen surfaces and two discretionary samples, which were "taken based on researcher observation during meal preparation and represented possible cross-contamination hot spots."

The swabs used to collect samples were put over ice and transported to the North Carolina State University food microbiology laboratory, where they were processed for MS2 detection.

In between each individual observation, each kitchen was sanitized with 10% bleach solution for one minute before wiping the surface with a clean, disposable paper towel.

The study found that in most of the meal prep, two or fewer swabs showed evidence of cross-contamination, but 81% of the time, one or more surfaces were positive for MS2. The authors said they believe people are mindful of wiping down surface areas, along with things like cutting boards, sinks, cabinet handles, but may not think about those spice jars.

To keep your spice containers clean and free of germs from cross-contamination, experts suggest washing hands often during food prep and making sure to wipe down any spice bottles used.