We are constantly told that bacteria on kitchen surfaces should be killed (with bleach or whatever) to avoid infection.
My questions are:
- Do you really get concentrations of harmful bacteria on the average kitchen surface? If so where do they come from?
and
- Short of licking the surface, how can they be ingested? I mean if I was to drop a slice of toast with honey onto an infected surface, I can imagine the bacteria adhering to this sticky substance. However if it was a dry slice of toast or some other solid, non-adhesive substance (a grape maybe) I can’t see how germs (a synonym for “bad bacteria”?) would attach themselves to it. And from what little I know, they aren’t exactly the speediest creatures on earth, so surely they can’t “migrate” to the slice of toast before I can pick it up…
Bacteria are only going to accumulate to dangerous levels if you spill food and don’t wipe it up properly; if you wipe down your work surfaces daily with ordinary detergent, there won’t be anything (much) for them to feed on.
If there is spilled food residue (or worse, liquids from uncooked meats) on your work surfaces, then it’s this, along with the bacteria that adheres to any food you put on it, not the individual bacteria themselves. But the residue doesn’t have to be particularly wet for some of it to adhere to even a dry cracker (after all, if you dropped a dry cracker on a piece of dried-up dog poop, you wouldn’t need any convincing that it was contaminated and not fit to eat, would you?)
Don’t forget about cutting surfaces. If you cut uncooked chicken on something, the juice will get into the cuts, and could show up on the next thing you cutting (and if the next thing happed to be say raw veggies, that could be a problem). That’s where bleach comes in handy. Many people have gotten very sick for that exact reason.
Ideally you should keep a separate chopping board for uncooked meats.
On a show about this topic, the researchers found that the dish rags and sponges were the number one source of bacteria, including nasty stuff like staph. I’d always suspected as much. Warm water, large internal surface areas. A clue: if they smell, then they’re surely full of organisms.
Every few days I microwave mine after using them. A couple of minutes gives them a good steaming. This won’t kill mold spores, but it sure keeps them from developing that “old washcloth” odor.
I believe most sources of bacterial problems in the kitchen come from cross-contamination (a subject that fascinated me). When I was a lab tech student, I read a case study of a guy who sliced an uncooked pork sausage with a knife, then used that knife to butter himself a slice of bread. He actually died from the bacteria that he ingested from the pork sausage residue that was on the knife (although it would probably be more accurate to say he died from the toxin that harmful bacteria such as Clostridium botulinum produce in food). A little goes a long way when you’re talking about food-poisoning. From this site:
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Your best bet is always to err on the side of not allowing any cross-contamination at all.
You can get harmful concentrations of bacteria from raw meats (as described above - pork, chicken, and hamburger are the worst offenders for this), raw eggs, and vegetables with dirt still on them (there may be bacteria in the dirt). Mayonnaise is another common offender; it seems to make an excellent growth media for bacteria at room temperature. As described above, the dishcloth is also a likely suspect; in between washing dishrags with bleach, keep them wrung out and hung up to dry to reduce bacterial growth. Another source people tend to overlook is allowing pet animals on kitchen counters. Part of that is the “yick” factor - your cat was just scratching around in the litterbox, and now she’s walking over your counter where you’re going to lay the bread for your sandwich? Not in my house.
As for cleaning kitchen surfaces, what we used in labs to disinfect everything was a 5% bleach solution. Normal detergents and soaps are bacteriostatic; that is, they don’t allow the bacteria to grow, and can be used for most normal cleaning conditions. There is starting to be a concern that we are using too many anti-bacterial products where it really isn’t needed, and we may start breeding resistant bacteria in our normal environments, as well as weakening our own immune systems by removing normal challenges. I would suggest using anti-bacterial products only in the kitchen for anything that comes in contact with any suspect food; use soap or cleaners and hot water everywhere else, and bleach in the laundry. Also, allow sun and fresh air in as often as possible; bacteria don’t like direct sunlight.
Wow, I didn’t know I had this much to say on this topic. But I always did find microbiology pretty interesting.