HELP! Why Does My Dish Washing Sponge Smell So Bad?

For less than $2 per month, get 1 soap dispensing handle and 6 dish cleaning sponge or brush refills

Your dish washing sponge smells because it is dirty and needs to be changed. We took to the streets of San Diego, California to ask people how often they changed their dish washing sponge and we were a little, ahem, grossed out by their responses. Although, before we started Backup Brush, we were guilty of the very same crime, aka sponge overuse.

The majority of people we talked to admitted they knew it was time to change their kitchen sponge after about 2-4 weeks of use. But they often continued using that smelly (need I add bacteria-ridden) sponge for another couple weeks before remembering to get a replacement. We get it… it’s SO easy to forget to buy a new sponge at the store. Sponges just aren’t that exciting, but they are important. After all, you count on them to clean your dishes, pots and pans – things you cook with and eat out of!

The number one way to stop your kitchen sponge from smelling and spreading bacteria is to CHANGE IT. It’s that simple. Of course, that’s easier said than done. Thankfully, you can subscribe to Backup Brush and get your dish sponges and/or brushes delivered to your door for less than you’d pay at your local store. Shipping is always free.

What is That Smell on My Dish Washing Sponge?

Perhaps you’re still wondering just why your sponge smells so bad? What is that notorious musty odor, and can it make you sick?

Your average used sponge contains millions of bacteria, and it only takes a few bacteria to make you ill. Therefore, your sponge could absolutely make you sick. Growing up, my best friend’s little sister became sick with salmonella after eating off a cutting board that had just been cleaned… with a dirty sponge. That dirty sponge had been used to clean chicken juices earlier in the day. And the rest of the story goes down in barfing history.

Once your sponge starts to smell, mold has probably already started to grow on it. Different bacteria have their own unique smells, but the musty smell commonly identified on sponges is often related to mold. Although, microbiologists have identified all types of bacteria growing on dirty dish washing sponges.

In one particular study published on the National Center for Biotechnology Information, 201 kitchen sponges from food establishments were randomly collected and assessed. Researchers found sponges contained Aerobic Mesophilic Bacteria (AMB), Enterobacteriaceae, Coliforms, as well as Yeast and Molds. The most dominant types included Bacillus, Micrococcus, Streptococcus, Pseudomonas, and Lactobacillus.

  • 9% of sponges contained significant coliform counts
  • Over 72% of sponges contained yeast
  • 45.7% contained mold

The study concluded by saying poor kitchen sponge sanitation practices were to blame. To combat the issue, researchers suggested sanitizing sponges in between use and changing your kitchen sponge regularly.

Why Does Bacteria Love Your Dish Cleaning Sponge?

There isn’t just one reason bacteria thrives in mass numbers on sponges. Instead, there are several reasons. For one, your sponge is wet a lot of the time and a wet environment is ideal for bacteria growth.

Secondly, you use your sponge to clean food and tiny food particles attach to the sponge and remain trapped there. As the food starts to decompose, it smells and adds to the growing bacteria population.

Furthermore, there’s a common misconception that cleaning your kitchen sponge can remove bacteria, but the truth is that it only removes some bacteria.

What about a soap dispensing dishwand—doesn’t the soap kill the bacteria in the sponge?

It’s easy to assume that’s how it would work, but unfortunately, it doesn’t. Instead, bacteria growing on the sponge becomes immune to the disinfectant properties in the soap. Therefore, bacteria thrive regardless of the fact soap is almost constantly in contact with the sponge.

Breaking Down the Bacteria on Your Sponge

Bacillus, Micrococcus, Streptococcus, Pseudomonas, Lactobacillus… what are these foreign sounding names belonging to the creatures crawling on your sponge? While some of the bacteria on your sponge are more friendly than freaky, there are some bad boys on the dish sponge block like E. Coli, Salmonella and Campylobacter.

Here’s some background information on the most common types of bacteria found on dish washing sponges.

Streptococcus: A highly contagious bacteria commonly associated with strep throat, but also known to cause scarlet fever, rheumatic fever, impetigo, streptococcal toxic shock syndrome, tonsillitis, and several respiratory infections. Streptococcus translates to “twisted berry,” which is in reference to the bead-like strings or chains that make up these bacteria. There are different strains of streptococcus and only some can make you super sick.

Campylobacter: Known to cause over 1.3 million illnesses each year in the US alone, campylobacter is the leading cause of bacterial diarrheal illness according to the CDC. It is commonly found in guts, feces, and raw poultry, as well as kitchen sponges. Sure, there shouldn’t be any feces in your kitchen sink, but remember, kitchen sinks are usually dirtier than toilets… so yeah.

Bacillus: Commonly found in soil and water, bacillus species can form dormant spores that remain active for a long time despite exposure to heat, sunlight, and chemicals. This makes them nearly impossible to get rid of. Even if you microwave your sponge, bacillus is there to stay (insert creepy music). Some forms of bacillus are harmful to humans and can cause food poisoning.

Pseudomonas: These bacteria are found throughout the environment, largely in soil, water and plants. Although, pseudomonas won’t usually make healthy people sick, they can cause mild illnesses.

Yeast: Yeast belongs to the Kingdom Fungi family. Unlike bacteria cells, yeast cells contain a nucleus. For the most part, your immune system knows how to handle yeast but if you have a weakened immune system it could make you sick.

Mold: Mold is also part of the Kingdom Fungi. Mold often originates on your sponge as a result of rotting food particles. Mold creates a nasty smell and could potentially make you sick.

Salmonella: This common bacterial disease is found in human and animal intestines. It is also found in feces (lovely, right?). Coming into contact with contaminated food and water are the most common causes of illness from salmonella, although a dirty kitchen sponge could be to blame as well.

E. Coli: While E. coli (Escherichia coli) is normally found in your intestines, certain strains can make you sick. Not so fun fact: did you know that 95% of urinary tract infections are caused by E. coli? More than likely, most of those have nothing to do with your kitchen sponge… but still, swallowing trace amounts of E. coli can make you sick.

Micrococcus: A member of the Micrococcaceae family, Micrococcus is commonly found in environments containing dust, dirt, and water. These bad boys aren’t so bad after all, in fact they are commonly found throughout the human body and help maintain balance.

Lactobacillus: This is considered a “friendly” bacterium because it naturally lives in the human body without causing harm. Plus, lactobacillus is added to certain fermented foods.

Tips to Make Your Dish Washing Sponge Last Longer

No one wants to be wasteful and so there’s no sense in tossing out a sponge every few days.  The goal is getting your dish washing sponge to last as long as possible. Here are some tips to help you accomplish that.

  • Replace your sponge at least once a month, although replacing it every 2 weeks is highly recommended.
  • Don’t use your sponge to clean up raw meat juices; use a disposable towel dish washing sponge cleans glass bowl instead.
  • Wash your sponge regularly in between uses. This will not remove all bacteria, but it will help. Put it in the dishwasher (warm water + dry cycle) or throw it in the microwave for 2 minutes. We recommend added a pinch of lemon juice to your sponge before putting it in the microwave to help remove odors.
  • Keep your sponge in a container or cup beside your sink so it has a better chance of drying out in between uses. This also helps reduce cross-contamination between your sink and sponge.