Dirty Sponge
Problem
Around my house, I am the chief cook and bottle washer. In this role I also maintain the dishwashing sponges. Several times daily my main sponge is carefully rinsed and squeezed as dry as possible. Despite this careful handling the sponges become stiff, as though there is some stiffening compound accumulating in the sponge interior.
Analysis
There was a segment on Morning Edition (NPR)1 regarding bacteria accumulating in and on kitchen sponges. It referenced an article published in Scientific Reports titled “Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella and Chryseobacterium species”2. Whew! What a long title! The gist of the article was that kitchen sponges accumulate massive numbers of bacteria (54 billion bacterial cells per square centimeter). The fear is that these bacteria can spread disease.
I know that many bacteria contain sticky substances that allow them to stick on surfaces and bacterial colonies stick together. So, these sticky bacteria or their slime may be accumulating in my sponges and making them stiff. BTY, these stiff sponges get demoted to wiping up spills on the floor and other less sanitary tasks. How do I get rid of these imbedded critters and extend the usable life of the sponge?
Solution
Bleach cleans sponges well, effectively sterilizing them. The sponge is restored to its original flexibility. The problem is that the bleach oxidizes the sponge material, causing it to disintegrate fairly quickly. So, bleach is out.
What about boiling? I was worried that boiling would shrivel the sponge material, ruining the sponge. This is not the case. The simple procedure is to place the sponge in a small pot, cover with ½ inch of water and boil for 5 minutes. The sponge can then be removed, squeezed and rinsed with clear water a couple of times. The water left in the pot is yucky semi-slimy. Throw that water out.
References
1. “So Your Kitchen Sponge Is A Bacteria Hotbed. Here’s What To Do”, Michaeleen Doucleff, September 11, 2017, heard on Morning Edition, National Public Radio, NPR – Dirty Sponge.
2. “Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella and Chryseobacterium species”, Massimilian Cardinale, Dominik Kaiser, Tillmann Lueders, Sylvia Schnell, and Markus Egert, Scientific Reports 7, Article number: 5791, Nature article.