Vinegar and 1/2 cup herbal tea make a floor cleaner; Mississippi State says peppermint adds antibacterial qualities

Somehow between sourdough starters and "clean girl" aesthetics, the internet rediscovered an old trick: mix vinegar, dish soap, and brewed herbal tea and mop your floors with it. Recipes are peppered with a confident little footnote that the use of peppermint tea, in addition to its pleasant scent, has antimicrobial qualities.

According to a Mississippi State Department of Health green cleaning guide, a floor cleaner can be made using liquid soap, white vinegar or lemon juice, with 1/2 cup of fragrant herbal tea, and peppermint is great as it adds antibacterial qualities. It's a widely repeated claim, and like a lot of folk cleaning advice, it's worth checking against what the underlying research actually says, not because the source is untrustworthy, but because recipe guides tend to simplify the science behind them.

The peppermint part, checked against the lab


There is real evidence for peppermint's antimicrobial properties, but it applies to concentrated essential oil, not a weak cup of brewed tea. A 2014 peer-reviewed study in the Songklanakarin Journal of Science and Technology, "Chemical composition and antimicrobial activity of peppermint (Mentha piperita L.) essential oil," found that concentrated peppermint essential oil showed antimicrobial effects against bacteria, fungi, and yeast in lab conditions, with potency varying by concentration and organism.

The gap between a lab-grade essential oil and a steeped tea bag is large: essential oils are far more concentrated than brewed tea, so evidence for the oil's antimicrobial effect doesn't automatically carry over to a floor mopped with tea. The fragrance is real; the disinfecting power is mostly aspirational.

The vinegar part is the bigger surprise

Vinegar is treated in the US almost like a wonder product: cheap, non-toxic, and pungent enough that you can tell at a glance it's been mixed in. But its cleaning power and its disinfecting power are two different things. A 2020 study in BMC Microbiology, "Did granny know best? Evaluating the antibacterial, antifungal and antiviral efficacy of acetic acid for home care procedures," found that household-strength vinegar did not reliably kill bacteria, fungi, or viruses, and that the acetic acid concentrations needed for disinfection were well above what's found in a standard kitchen bottle of vinegar.

The same study found that combining acetic acid with citric acid had antimicrobial activity, meaning it could inhibit or reduce microbial growth, without reaching the higher bar required for disinfection, which is the near-total elimination of pathogens as defined by regulatory standards. That's a difference of degree, not a contradiction: a solution can slow down or reduce germs without clearing enough of them to count as "disinfected." Vinegar's absence from the EPA's registered disinfectant list reflects the same gap, it has never been submitted for or granted disinfectant registration by the agency.

So is this floor cleaner pointless, then?

Not really, but it has been overinflated by a combination of good marketing and the natural inclination towards pseudoscience that the wellness millennial holds dear. The liquid soap in the recipe is doing the hard work of removing grit and grime, which is the most important part of floor cleaning; the vinegar helps to lift off grease and mineral deposits, while the peppermint tea mostly provides fragrance, with potentially some antimicrobial assistance.

For routine floor cleaning, this mix can reasonably freshen up floors and cut through everyday grime, but it is not a substitute for a disinfectant in situations that call for one. If disinfection is actually the goal, after illness, or in homes with pets prone to accidents, the safer move is an EPA-registered disinfectant suited to the surface, used exactly as the label directs, rather than stretching a DIY recipe to do a job it was never tested for. It's a good reminder that cleaning advice from credible-sounding sources can still get generalized well past what the original research supports.