What's the best way to sterilize a digital folding probe thermometer ?

Recently purchased a digital folding probe thermometer. It was not cheap, but in my book worth every penny. My meat cooking skills improved dramatically. But here is my question. The instruction manual states very clearly that the probe should be sterilized before and after each use. How do professional chefs or really sophisticated home cooks do it? A pot of boiling water on the stove? A solution of some kind? Soap and water? Is there an easy elegant way to accomplish the job?

  • Posted by: Linn
  • December 2, 2012


Smaug February 26, 2017
I would say listen to Chef Ono, who appears to have actually researched the subject, but keeping it in a glass of Vodka might help, and would anyway avoid more toxic elements.
caninechef February 27, 2017
Actually I was told by someone in the veterinary field that a
a) alcohol swabs for injections actually do very little other than make the patient feel like precautions are being taken. b) alcohol does have sanitizing effects but takes much longer to act then the exposure from a little presoaked packet.

Think about those jars of combs at barbers and hairdressers soaking away, which I have always found rather gross. Presumably if just a quick swish in alcohol worked they could do away with said gross jars.
Smaug February 27, 2017
Not really my field, but, for instance, hospital workers rely on alcohol against some pretty nasty and persistent stuff, including MRSA.
Betty February 26, 2017
I do food demos and always concerned about the food thermoters being free of bad stuff. What about vinegar as a sanitizer,saw it mentioned but not answered? Thanks
Ophelia December 4, 2012
Can we all agree that what we want to do with the thermometer is *sanitize* it rather than sterilize it? To actually sterilize it you would have to do something like put it through an autoclave. What you actually need to be doing is removing cooked and uncooked food from the probe so that it doesn't rot or cross contaminate your other food with raw, contaminated, rotting or dried on food. You can do this by wiping with alcohol or carefully cleaning with soap and water or by using a bleach solution which is replenished every hour or so. You never want to put any thermometer through a dishwasher or sanitizer because it can mess with the calibration (beyond the fact that digital thermometers would die).
If you are a home cook and not in charge of making meals for lots of people in a professional capacity I would just make sure I was cleaning it with soap and water before and after use. Unless you're sick, in which case you probably shouldn't be cooking anyway.
Linn December 3, 2012
Okay Chef Uno, you have sold me on the alcohol swab. Very impressive the depth of knowledge you bring to the discussion and I am very appreciative that you have taken the time to share.
ChefOno December 3, 2012

No doubt about it, what we commonly refer to as bleach (sodium hypochlorite) is poisonous. As is hydrogen peroxide -- another bleach. They both work in the same way, i.e. they are both strong oxidizers which destroy cell membranes of bacteria and viruses. They also both attack human skin in the same manner, as well as mucous membranes. So, pick your poison. They're both approved by the EPA as effective against norovirus so no harm in choosing one over the other as far as I know. How harsh each is perceived depends upon concentration and contact time depends upon concentration (see post above).

Hilarybee December 3, 2012
Chlorox brand wipes are really great. They actually use quaternary ammonium ions- and are pretty safe for home and industrial use. Like Shuna, I think bleach is really harsh and not necessary for home use.
ChefOno December 2, 2012

I'm not a microbiologist and certainly not a virologist but I'll do my best to explain of the some issues raised here.

"Quick wipe of vinegar" No, for two reasons, quick being key. While acids can serve as disinfectants, it takes considerable contact time for them to be effective. The same holds true for the old standby, bleach. Combining the two -- very carefully to avoid release of poisonous chlorine gas -- is even more effective against more pathogens but still requires a prolonged time to get the job done. I'm talking on the order of between 10 and 30 minutes depending on concentrations, combinations and target organism.

Antibacterial hand wipes vary considerably as to the chemicals used and the pathogens they are designed to destroy. They are formulated to prolong contact with the skin, meaning the solution won't evaporate completely or quickly enough and can be carried into your food. Or my food if you're cooking for me. As an adjunct to hand washing they can be useful but please don't use them on your thermometers.

Alcohol swabs are cheap, convenient and require minimal contact time to be effective. 10 seconds is sufficient for 70% isopropanol to kill all the usual suspects plus many viruses (unfortunately not norovirus, the dirty little bastard of food poisoning). Counterintuitive as it may be, a higher concentration of alcohol is usually *less* effective than the common 70% solution so stick with that. (If anyone cares it's because proteins are denatured more quickly in the presence of water.)

What a quick swab with alcohol won't do: Kill norovirus which is responsible for just over half of all foodborne illness in the U.S. It would take at least a full minute so remember that if you're depending upon a hand wipe to protect you from illness. A high enough concentration of sodium hypochlorite will also work but, according to the CDC, it requires 5000 ppm (3 ounces of 6% chlorine bleach per quart of water) to get the job done -- 6 times the standard disinfectant concentration (which for quick reference is 1 Tbs. / quart @ 6%). Stinky and a potential health hazard in itself.

The best defense is the vigorous application of soap and water for a full 20 seconds before handling food, regularly disinfecting food-contact surfaces, and cooking to 140F (hard to do with lettuce so it's best to rely on the first two and hope the restaurant staff knows as much about the subject as you do).

bigpan December 2, 2012
I keep a spray bottle of water with a couple splashes of bleach in it (enough so you can just smell the bleach).
I spray everything after washing - knives etc.
Works like a miracle to get beet juice off wooden cutting boards.
Shuna L. December 2, 2012
I'm going to go out on a limb here and say Bleach is poison. It is a really harsh solution for most simple problems. Before WWII, bleach did not exist, but peroxide did. Bleach is incredibly cheap (although peroxide is cheaper) and so has become the "fast and easy" go-to for our industrialized food manufacturing sterilization, but I don not believe it is necessary in our home kitchens. Try lemon juice on your cutting board, or a peroxide solution. Please at least have a think on it.
peicook December 2, 2012
The alcohole will disipate quickly and there will be no lingering taste. I will get some wipes tomorrow and will feed back.
Linn December 2, 2012
Thank you all for so many good answers so quickly. Alcohol is excellent disinfectant, but not sure how comfortable I feel injecting it into a piece of meat. But would an acid , say apple cider vinegar do as we'll?
peicook December 2, 2012
A great answer and I will mend my ways.

Voted the Best Reply!

ChefOno December 2, 2012

Alcohol swabs (think back to the last time you got a vaccination or had blood drawn) are available at your local supermaket, drug store, and places like Costco for a penny or two apiece. They are quick and simple to use and storing them where you keep your thermometer should remind you to use them every time.

Excellent question by the way and I hope it prompts everyone to think about how easily a dirty thermometer probe can cross-contaminate food, carrying pathogenic bacteria deep into a piece of meat or that cheesecake you're about to let cool on the counter. A damp cloth, especially one that is more than 4 hours old, is a cesspool of germs just waiting for a chance to send your family to the doctor (who may well pull out his own supply of alcohol swabs).

peicook December 2, 2012
I wonder if a quick wipe with vinegar would work?
susan G. December 2, 2012
Alcohol is the active 'anti-bacterial' agent, so DIY should be easy.
peicook December 2, 2012
OMG it has never occured to me to do that. I usually just wipe with a damp cloth.
Monita December 2, 2012
I've read that people use anti-bacterial wipes to clean the probe
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