
You are ruining your Stanley cup by cleaning it in the dishwasher. Here’s a safer way
By Pamela Vachon | Published: 2025-10-29 11:00:00 | Source: CNET
If you buy a Stanley tumbler During her viral rise to fame, it’s time to give her a deep clean. Even if you only use it for water, this reusable cup with all its nooks, crannies and loops is sure to harbor mold or any other substance you don’t want near water – let alone in your mouth.
The same components that make the Stanley so comfortable—the straw, lid, and various crevices—also create multiple surfaces where bacteria and debris can accumulate. Although putting a mug in the dishwasher may seem logical, cleaning professionals advise against this method. Proper maintenance is essential to prevent buildup of dirt and potential Mold growthBut a dishwasher may not be the most effective solution for these complex designs.
We turned to an expert for the best way to clean your Stanley travel mug.
“Cleaning Stanley cups regularly is essential to keeping them clean and safe to drink from,” says Sabrina Tretiakova of FOTADOR, a certified cleaning technician through the International Sanitary Supplies Association. “Factors that affect the growth of bacteria and mold in Stanley cups include moisture, nutrients from the beverages themselves and lack of regular cleaning,” she says.
Babies hydrate. Stanley’s large travel sized water cup has become very popular.
Parts of your Stanley cup that need cleaning
There’s more than meets the eye when it comes to the different parts of a Stanley Cup or insulated mug, and that’s not enough even if you regularly wash the inside of the mug and the drinking mechanism. Here are several problematic areas identified by Tretyakova:
The first step is to completely disassemble the Stanley Cup so you can clean all of its parts.
Under faucet protector
Depending on your drinking vessel, this is easy to miss because it’s not a piece that your mouth directly touches. However, it often comes into contact with the faucet that your mouth touches, allowing bacteria and mold to build up.
Straw and cover
“These parts are prime sites for bacterial growth because they come into direct contact with your mouth and beverages,” Tretyakova says. “The bacteria could be oral flora lurking in your mouth and being transferred to the cup.” (If “oral flora” doesn’t send you straight to the kitchen sink for an instant deep clean, I don’t know what will.)
Rubber seals
Certain models have rubber seals on the lids to help keep them tightly closed, but this is another area that Tretyakova identified as troublesome in terms of hygiene. “The areas below the seals are susceptible to mold contamination if not cleaned properly,” she says. “Typically, this area becomes infested with black mold, also known as Stachybotrys chartarum.” (Choose your own adventure: Which is scarier, mouth plants or black mold?)
How to clean a Stanley tumbler or insulated cup
Here are Tretyakova’s recommended best practices for cleaning and maintaining your insulated cup.
An old toothbrush is perfect for cleaning those pesky nooks and crannies.
1. Regular rinsing
“Rinse the cup and lid under hot water shortly after drinking the beverage,” Tretyakova says. “It helps remove any residue that could harbor bacteria.” This is not a substitute for cleaning a cup, but it is a good habit to get into, especially if you are in a work or public environment and cannot do so right away.
2. Thorough cleaning
First, completely disassemble the Stanley Cup or other insulated cup so that there are no hidden areas that may harbor moisture and could encourage bacterial growth. Tretyakova recommends using mild dish soap and warm water to soak the removable cup parts for 15 minutes. (Throwing the cup in there is also a good idea while you’re doing this.)
Scrub the parts with a clean toothbrush or bottle brush, then rinse with warm water. You can hand dry any parts that are easily accessible with a clean towel, but other parts, such as straws, should air dry.
We’ll dive into how to best clean your new Stanley cup.
3. Avoid the dishwasher
The Stanley Cup and some other insulated cups may be dishwasher safe, but dishwasher use is not necessarily recommended for best cleaning. “The dishwasher may not reach all the nooks and crannies on your cup lid,” says Tretyakova, who recommends hand-washing regularly for best results.
4. Periodic deep cleaning
Tretyakova recommends periodic deep cleaning in addition to daily scrubbing, which can be done with distilled white vinegar and baking soda.
Steam cleaning for added peace of mind
This $50 Clorox Compact Steam Cleaner will give your mug a deeper clean.
For those who are about to ditch insulated cups forever, take note: There’s more you can do to keep your cup clean and sterile. Similar to bottle cleaners sold as baby products, steam sanitizers are available for many household uses, for which insulated cups are prime candidates.
“The rubber seals and slots of the sliding lids can trap moisture, even after washing, and straws are a challenge because of their length and shape,” says Nicole Backus, product manager at the company. Clorox Housewares. When humidity is the problem, moisture in the form of vapor can also be the solution.
“Steam sterilization is especially beneficial, as steam can penetrate cracks and crevices that scrub brushes, soap and water can’t reach,” Backus says. “Sterilizing the clean parts of the insulated cup prevents bacteria from growing on the surfaces of the cup, inside and out, from top to bottom.”
Sterilizing should be done after washing, not instead of it, but for added peace of mind, you can get a home use sterilizer e.g Clorox double layer steam sterilizer For less than $50. (You’ve already spent this amount on Stanley, so consider it insurance.)
ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ


