I’ve washed dishes by hand all my life. There was a dishwasher, once, but it was old and busted and eventually got used for storage. So I know the routine well, of standing there with your hands in hot soapy water and staring at the wall… and the dishes never end. You can wash them all, send the kids running all over the house on a dish walk to make sure you didn’t miss one. But still, no sooner will your sink be shiny than someone will set a coffee cup in it.
Most of the time, washing dishes is something we learn early and never think about. You have lots of hot water, there’s soap, and then you rinse, and dry. Very hot water. I remember learning that from my grandmother, who taught me that the dishwater needed to be almost too hot to put your hands in.
What happens if you can’t? Imagine you’re out camping. How do you wash and make sure you’re not exposing your food later to pathogens? Since I know many of you will never do a long camping trip like that – and I miss wilderness camping but it’s unlikely I’ll get those chances again – imagine instead there is a weather thing, and you lose electricity. Now this means you have very, very little water.
All my life, I can remember Dad telling me that if I didn’t get all the soap off, I’d make the family sick. Soap causes digestive upset and diarrhea. I don’t know if Dad had a bad experience, but it was his mantra when he saw me washing dishes. “Get all the soap off!”
Well, Dad, I always tried. And then in Chemistry lab a couple of years ago, my professor taught us all how to wash dishes scientifically, with precision and using as little water as possible. It may seem like an unlikely place to learn a kitchen task, but in the era of dishwashers I’m sure there were more than a few in the class who had no idea how to really wash dishes. Also, we were using de-ionized water for final rinses, and it’s expensive and hard to make, so conservation of DI water was important.
So here’s the experiment to make certain your dishes are really clean and hygienic.
In a clear drinking glass, or white cup, put some water with a good bit of food coloring in it. Pour that out. You will notice that what is left clinging to the inside of the glass is still colored (we used blue food coloring, which worked well for visuals). Here’s the thing: glass is polar, and so is water, so it will adhere to the inside of the container. Now, the object of this game is to rinse all the color out using as little water as possible.
We were using graduated cylinders and pipettes, which you’re unlikely to have in your kitchen. So first, try a single rinse with about a half cup of water, swirl it around and pour it out. Still see blue? How many rinses does it take to stop seeing blue? How many cups of water did you use?
With another glass of colored water, dump the colored stuff and now, carefully pour, swirl, and dump water a tablespoon a time. If you have an eyedropper to run it down the sides, ideal (this is effectively what we were using in Beral pipets). Repeat this 4-5 times. Still see blue?
What you’ve just done is demonstrated dilution, but that’s not really relevant to this. In a situation where you have very little potable water, you can use the stuff you’re not sure of (creek water, melted snow water, what have you) to first eliminate any crusty bits and gunk. Then you use the potable water (i.e. the stuff with no germs in it) to rinse carefully, and what you’re left with is a clean vessel that can safely be used for drinking and eating.
For a more every-day approach, you should always keep in mind the rule of threes. Once you’ve scrubbed the dish, rinse it three times to ensure there’s no soap residue. If the water sheets off a smooth surface, you’ve gotten all the soap and residual oils off it.
And for the boredom, I usually use a tablet playing a video, even if it’s a lecture video, and let my hands go on autopilot. The only thing better is to have company standing next to you chatting and drying while you wash!