Yttrium2
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Sanitary dishwashing
I've got a few questions about washing dishes after trying to make some homemade dishwashing liquid with a bar of dial soap, and a bit of washing
soda.
Questions
Why is washing soda added to water and grated bar soap if it doesn't reduce scale residue? - it says this with reference attached according to
Wikipedia.
My soap mix formed a lather on the surface of the water, but it did not make a good emulsion like dial soap does, why is that?
I had nothing abrasive to scoured the dishes with, which brings me to my next question -- Sanitary dish washing -- is the main focus to scrape germ
cultures off the dishes, and get them to wash away in the water, or is the main focus to kill the germs? Surely washed dishes aren't anywhere near
sterile. Err, my question is what's the difference between sanitary and sterile? Sorta.
When it comes to dishes it seems the idea is just to scoure the crap off, and have some sort of a god only knows what surfactant that'll get the
grease and water to mix, so that they can be rinsed off.(my guess is a soap that forms an emulsion with water alone? How is that possible?) This
doesn't leave a sterile dish, but it leaves a sanitary one, correct?
Soaking dishes in bleach seems a little silly, dad always used to do it, when we were camping, I can remember... Him and is galvanized bucket of
bleach water, heh. It seems to me the main idea behind cleaning a dish is getting the stuff unstuck and not necessarily attempting to sterilizing the
dish, correct?
As soon as the dish is removed from bleach there are airborne spores and god only knows what landing on the dish.
Also, soap scum residue is more likely to form on fabrics that it can adhere to vs smooth ceramic dishes, right?
Can can't a scouring pad cut grease better than soap?
Bonus question, can anyone explain why all the plates, bowls, ect in my house are made of melamine? I hate the shit because it can't be microwaved...
[Edited on 2/17/2018 by Yttrium2]
[Edited on 2/17/2018 by Yttrium2]
[Edited on 2/17/2018 by Yttrium2]
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j_sum1
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Pathogens are organisms. They require an energy source if they are to reproduce and colonise the surface of your flatware. Therefore by removong all
food you prevnt them from colonising the surface. You won't get rid of every last microbe but you don't really need to. The air is full of them and
they don't do you any harm at all. What you need to do is avoid ingesting a large amount of some of the nastier ones next time you use your plate --
your immune system may not have time to activate before the numbers get out of control.
Soap scum is something to avoid promarily because it is unpleasant to look at or to taste.
Detergents designed for dishwashing are good for what they are designed to do. I don't really understand why you are trying to duplicate teh process.
You are unlikely to gain anything by it.
The camping / bleach trick is an attempt to kill germs under conditions where hot water is less available. Under camping conditions there is more
likely to be foood remains on the plate and therefore there is some sense in disinfecting. Bleach is as good as anything and better than most.
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aga
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Funny thing about Bleach.
One would imagine that stronger = better, yet it is not so.
Apparently above around 5% concentration, the bacteria 'huddle' into clumps, preventing the bleach getting to the ones in the middle.
Around 5% is where the bleach is most effective as it can get to all of the bacteria, despite being slower-acting.
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Vomaturge
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When you say the soap mix did not make a good emulsion, are you referring to how it mixed with water or how it cleans dirt off of dishes? Why is it
less effective than the dial soap by itself? I'm not sure it may have to do with concentration and the amount applied, or maybe dial doesn't work well
with extra sodium carbonate added? Part of the problem is that it's hard to know all of the ingredients in the soap, and how they might behave. So I'm
not really sure what's going on here.
I think that cleaning dishes takes of the food particles and probably gets rid of some (not all) bacteria as well. Like j_sum1 said, the main goal is
to have low amounts of bacteria, as opposed to high amounts if there is old rotten food on the plate.
Scrubbing alone can get big pieces of dirt or drips of grease off, but it often leaves little particles or thin liquid films behind. Soap helps the
process by removing small bits of (water insoluble) grease from the dish, and by helping disperse the grease into the water after it has been scrubbed
off. That way it doesn't get smeared back onto the dish. I do think it forms an emulsion, like you said.
Incidentally, the way many soaps do this is with molecules which have one end that would be water soluble if it were by itself. This end has a sodium
or potassium atom (think of a soluble compounds like NaCl or NaOH) and an oxygen atom. The other end is grease soluble, and is mostly carbon/hydrogen,
like grease or candle wax. What happens is the "grease" ends dissolve in the grease you are cleaning, and the "sodium" ends dissolve in the water, and
they bel carry grease away, and keep it from clumping back together. In a way, it's a 'bridge' between polar (water soluble) and non polar (grease
soluble) molecules, to help them mix. Still, it requires some scraping and agitation to break up the grease first.
Okay, I know soap molecules are a bit more complex than that. They are actually the sodium/potassium salts of fatty acids. They are made by reacting
grease (fighting fire with fire, right? ) with sodium hydroxide or potassium
hydroxide.
As for melamine dishes, I think the idea is that the plastic is slightly more flexible than ceramic, and not as heavy, so it doesn't break if you drop
it. It might be cheaper, too. Of course, it cannot withstand as high of temperature, and may also absorb microwaves and heat up faster. So that's a
downside.
Oh, and thank's for telling about the bleach concentration thing, aga. I've never heard of that before, and its good to know.
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Texium
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Thread Moved
18-2-2018 at 09:18 |
Tsjerk
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I would say 5% bleach is overkill, 0,1% is effective against tuberculosis, which is one of the most resistant species because of an extra layer they
have around the cell.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4671544/#!po=57...
Here they say ten minutes 0,5% is enough for the most resistent Clostridium spores.
https://www.google.nl/url?sa=t&source=web&rct=j&...
I always used 0.1% overnight, plus twenty minutes 120 degrees in an autoclave to get rid of background noise in protein MS, worked like a charm, not a
single chard of protein survived that treatment.
For cleaning I think 0.1% NaOH is a winner, it creates its own soap/soluble salts with most organics. Too bad you shouldn't get it in your skin or
eyes.
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happyfooddance
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Quote: Originally posted by Yttrium2  |
My soap mix formed a lather on the surface of the water, but it did not make a good emulsion like dial soap does, why is that?
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There is a difference between a soap and a detergent. Dial and most other dish soaps contain detergents. You can buy sodium lauryl sulfate very cheap
from a lot of vendors online; adding a small amount of this to your home-made soap will greatly improve it's cleaning ability, especially in hard
water.
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Tsjerk
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Yes! 0.1M NaOH plus 1% SDS (sodium dodecyl sulfate) of SLS, this will kill/clean just about anything.
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