# Dry your sponges! **URL:** \ **Category:** Cafe Society\ **Created:** [June 19, 2019, 3:20pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744 "2019-06-19T15:20:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [June 19, 2019, 3:20pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/1 "2019-06-19T15:20:28Z")
The latest issue of _Cooks Illustrated_ has the results of a test where they compared leaving a wet kitchen sponge in the sink (actually in a bowl) vs. wringing it out and storing it in a dry place. I’ve always assumed a wet sponge would grow more bacteria than a dry one so I wring mine out. But the magnitude of the difference is pretty shocking. After 14 days of using the sponges, they were lab tested with the results reported in “colony-forming units per milliliter”: Dry sponge: 20 CFU/ml Wet sponge: more than 500,000 CFU/ml :eek: ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [June 19, 2019, 3:38pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/2 "2019-06-19T15:38:06Z")
Nuke 'em. I put ours in the microwave for two minutes. That’s advice I’ve seen elsewhere so I’m surprised it wasn’t offered. ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [June 19, 2019, 3:38pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/3 "2019-06-19T15:38:47Z")
[Or run them through the dishwasher, heat them in a microwave or dunk them in a bleach solution for one minute.](https://www.canr.msu.edu/news/sanitizing_kitchen_sponges) Go Spartans! ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [June 19, 2019, 4:09pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/4 "2019-06-19T16:09:53Z")
Cooks Illustrated says their tests show that boiling for 5 minutes is better than microwaving or using bleach. I also seem to recall (but can’t find it right now) that CI once got a letter from a microwave manufacturer who said they don’t recommend heating sponges in their microwaves. I don’t remember why. But in any case, I don’t have the discipline to do any of those things every time I use a sponge, but I can certainly squeeze it out and set it in my sponge holder. I do run it through the dishwasher every few days. ---
**Author:** ![Procrustus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/procrustus/32/2994_2.png) [@Procrustus](https://boards.straightdope.com/u/Procrustus)\ **Post date:** [June 19, 2019, 4:13pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/5 "2019-06-19T16:13:16Z")
I think I throw mine away before we reach the 14 day mark. ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [June 19, 2019, 5:02pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/6 "2019-06-19T17:02:09Z")
Nice. I have a dish rack so I just let mine dry in the dish rack. I have no idea what CFUs are but I’m ok with 20. I also don’t use the same sponge for dishes and countertops. And I toss them out every few washes (you can buy a bag of them at Dollar Tree!) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [June 19, 2019, 7:18pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/7 "2019-06-19T19:18:55Z")
Tossing a wet sponge into the microwave doesn’t take any discipline or else I probably wouldn’t do it. Boiling for five minutes? Never gonna happen. The sponges (actually, scrubbers with one teflon rough side for cleaning pans) go through daily microwaving without any noticeable damages of any kind. ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [June 19, 2019, 9:14pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/8 "2019-06-19T21:14:43Z")
My nose has pretty much always been able to tell me that much. If I get distracted and leave a wet sponge I immediately know the next day when I walk in the kitchen by the stink. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [June 20, 2019, 3:47am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/9 "2019-06-20T03:47:23Z")
> [@Exapno\_Mapcase](#): > > Nuke 'em. Preferably from orbit. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 20, 2019, 3:59am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/10 "2019-06-20T03:59:21Z")
> [@ZipperJJ](#): > > I have no idea what CFUs are but I’m ok with 20. A colony-forming unit means a viable bacterium capable of growth. The sample is plated on petri dishes in serial dilution and incubated. A concentrated sample will just have a mat of overlapping growth. But eventually you reach sufficient dilution that you can distinguish individual well-spaced colonies on a dish - each of which originated from a single bacterium. Count the colonies on that dish, scale up according to the dilution factor, and you have an estimate of the concentration of bacteria in the original sample. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 20, 2019, 4:06am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/11 "2019-06-20T04:06:39Z")
What the others said…I don’t think I would ever even think of that. I mean, I know it’s a thing, I would just never think about it. Luckily, I rarely use sponges. I have a dishwasher for dishes, a nylon scrub brush for things I need to scrub (which isn’t that often, and it goes in the dishwasher once a week or so, on heated dry) and about when I need to clean something stubborn like a shower or stained sink, I use a magic eraser and then throw it out (they’re more or less a one time use item anyway). ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [June 20, 2019, 5:07am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/12 "2019-06-20T05:07:52Z")
I’m not a petri dish. I think I can stand coming into contact with normal household bacteria without serious consequences, and the more often I do so, the stronger my immune system is. (Anecdote alert) We don’t do any of those things in our house, except to usually allow the sponge to air dry. Otherwise we don’t disinfect anything much in the kitchen. And we don’t get sick. So as far as I’m concerned you can save your :eek:s for global warming or something equally serious. ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [June 20, 2019, 5:45am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/13 "2019-06-20T05:45:09Z")
I’ve read that techniques like microwaving and dishwashing are not as good as they sound - they kill of some of the more harmless bacteria but leave the more dangerous versions to flourish. I don’t know how true that is. In Indonesia, they will keep sponges immersed in very soapy water while not in use. That’s what I do, since my area is extremely humid and sponges don’t dry quickly. Any sponge that doesn’t pass the sniff test gets chucked immediately (or downgraded to a use where supreme hygiene is less important, like wiping up spills from the floor). And sometimes I just pull out a new sponge because I don’t recall having gotten a new one in a while. I dunno, though. I am all for cleanliness but I try not to go crazy. When I was a little kid, my mother always wiped my mouth roughly with the kitchen sponge after I ate. I dreaded it because the sponge always smelled stinky. (I have an unusually keen sense of smell; I’m not trying to imply my mother’s kitchen was dirty.) And yet to my knowledge, getting my mouth wiped with a stinky sponge everyday never made me sick. Who knows, it may have boosted my immune system! ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 20, 2019, 12:39pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/14 "2019-06-20T12:39:03Z")
We switched from sponges to Swedish dishcloths last summer. They’re made of paper and cloth, and they can be cleaned in the dishwasher, microwave, or the normal laundry. They can be wrung out and hung over the faucet; being thin they air dry very quickly. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [June 20, 2019, 1:33pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/15 "2019-06-20T13:33:32Z")
> [@Riemann](#): > > A colony-forming unit means a viable bacterium capable of growth. The sample is plated on petri dishes in serial dilution and incubated. A concentrated sample will just have a mat of overlapping growth. But eventually you reach sufficient dilution that you can distinguish individual well-spaced colonies on a dish - each of which originated from a single bacterium. Count the colonies on that dish, scale up according to the dilution factor, and you have an estimate of the concentration of bacteria in the original sample. Thanks for this answer. I always wondered how researchers did these colony counts but never cared enough to look up the process. Ignorance fought. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [June 20, 2019, 2:15pm UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/16 "2019-06-20T14:15:47Z")
Ee don’t use sponges in the sink – we use dishcloths, which are always spread out to dry after use. The idea of using a long-damp cloth to clean dishes (what some families evidently call a “toadcloth”) freaks me out. ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [June 22, 2019, 12:49am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/17 "2019-06-22T00:49:19Z")
> [@DCnDC](#): > > We switched from sponges to Swedish dishcloths last summer. They’re made of paper and cloth, and they can be cleaned in the dishwasher, microwave, or the normal laundry. They can be wrung out and hung over the faucet; being thin they air dry very quickly. I just looked up Swedish dishcloths on Amazon, and they look fantastic. I’ve ordered a bunch. Thanks for the tip. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 22, 2019, 1:06am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/18 "2019-06-22T01:06:34Z")
> [@CairoCarol](#): > > I just looked up Swedish dishcloths on Amazon, and they look fantastic. I’ve ordered a bunch. Thanks for the tip. We really like them. Since they come in all kinds of different designs we got a bunch of different ones, mixed them up, and gave a set to everyone for Christmas last year. They were a big hit. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [June 22, 2019, 1:48am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/19 "2019-06-22T01:48:37Z")
Them colonies can grow as much as they want overnight. The next day, when I rinse out the sponge in hot water, most get flushed down the drain anyway. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 22, 2019, 2:12am UTC](https://boards.straightdope.com/t/dry-your-sponges/835744/20 "2019-06-22T02:12:19Z")
> [@Roderick\_Femm](#): > > I’m not a petri dish. I think I can stand coming into contact with normal household bacteria without serious consequences, and the more often I do so, the stronger my immune system is. (Anecdote alert) We don’t do any of those things in our house, except to usually allow the sponge to air dry. Otherwise we don’t disinfect anything much in the kitchen. And we don’t get sick. So as far as I’m concerned you can save your :eek:s for global warming or something equally serious. Ding ding! FWIW I am not eating my household sponges. Not a single ml of 'em. I’m not even wiping my food with it. Do any of you? How many reported cases are there of illness specifically transmitted by household sponges? Maybe someone with better search skills can find some but I find … zero case reports. NONE. We do not live in sterile environments. We are not sterile environments. Funny enough early exposure to more cow … microbial products … helps[protect](https://www.uchicagomedicine.org/forefront/biological-sciences-articles/2016/august/growing-up-on-an-amish-farm-protects-children-against-asthma) from developing asthma and allergies in the Amish. (Very cool study.) Don’t use the sponge to clean up raw meat, poultry inclusive, or its juices. That’s gross. Cook your meat. Wash your veggies and fruits before cutting them. Those actions do some real good. Biggest vector for transmitting food-borne illnesses, besides the food? _You._ Your hands specifically. Wash your damn hands before and after food prep and during too. Right now you are touching a cesspool, [that keyboard in front of you](https://www.huffingtonpost.co.uk/entry/this-is-how-many-germs-are-on-your-keyboard_uk_57ff9322e4b0010a7f3e12d9?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAADSyO8UpWYLL45vIm-IRJt30GLkNwHW289blQzlcsRcgym8vo97EAh1oXAFRc3ufuuTgBZD-Tm40gkFbFHcHLbPganjogdhCDCPcYEhDhi6pe1YeG-LeYrd3JdwXyaH6OeqJMELApE-q9WtPhAwcyEnOpdzlDltDaYKiTp1qJLl1). Over 3.5 millions CFUs/ sq inch! 20,000 times more than a toilet seat. Do you ever snack while typing? While talking or playing on your phone? Or even just eaten after handling one or the other without washing your hands first? Has it killed you yet? Many many more bacteria there than on the surface of a sponge or the counter you wiped with it. [Next page](https://boards.straightdope.com/t/dry-your-sponges/835744.md?page=2)