Those stubborn orange or rust-colored stains on your towels—especially around the edges or in damp folds—are frustratingly common, and they’re usually not from dirt or food. Instead, they’re most often caused by one of two culprits: bacterial growth or iron in your water. Here’s how to tell the difference—and how to fix it.
Cause #1: Serratia Marcescens (Pink/Orange Bacteria)
Despite the name, this bacteria often appears pink, orange, or even reddish-brown—and loves warm, moist environments like bathrooms.
- Where it grows: Damp towels, shower curtains, sink drains, toilet bowls.
- Why it happens:
- Towels stay damp too long between uses
- Poor bathroom ventilation
- Residual soap or fabric softener buildup (feeds bacteria)
- Why it won’t wash out: Regular detergent doesn’t kill this resilient biofilm.
Fix it:
- Wash towels in hot water with 1 cup white vinegar (no detergent).
- Follow with a second wash using ½ cup baking soda + detergent.
- Dry completely in the sun if possible (UV light kills bacteria).
- Keep towels dry between uses—hang to air-dry fully.
