The manual for my dishwasher says to refill salt just before running a wash cycle, because if any grains of salt spill onto the stainless steel interior it will corrode. If it runs right away, no issue because the salt is quickly dissolved, diluted, and flushed.
So then I realized when I cook pasta I heavily salt the water (following the advice that pasta water should taste as salty as the ocean). But what happens when I leave that highly salty brine in a pot, sometimes for a couple days to reuse it? Does that risk corroding the pots?
You reuse pasta water? That’s kind of gross. Starchy water sitting around is a breading ground for bacteria. Don’t do that.
Also, dishwashers don’t clean with salt water. They use the salt to reset their internal water softener.
Starchy water sitting around is a breading ground for bacteria. Don’t do that.
That water is brine, if you do it right. Salt is a good preservative. I’ve tested it with up to 2 reuses.
Also, dishwashers don’t clean with salt water. They use the salt to reset their internal water softener.
Not sure why you thought I thought dishwashers clean with salt water. The manual’s advice was to mitigate salt grains that did not get into the salt reservoir that would sit on the stainless steel potentially for days.
Brine is the exact condition that life needs/thrives in. “About as salty as the ocean” is really good at supporting microbial growth. Source
i get 403 forbidden w/that link. And archive.org chokes on it too for some reason. Does your source counter this source?
(edit) ah, I see the problem. Salt only works as a preservative by drying out food.
Life started in the ocean, so logically this makes no sense.
Actually that logic is broken IMO. A food preservative need not make life impossible for all organisms. E.g. hops (and consequential acidity) preserves beer to some extent by making life hard for some unwanted organisms. But hops do not kill everything (of course, because you intend to drink the beer). Beer can still spoil despite the hops.
But as I said in my correction, salt works as a preservative through a drying effect, which I did not previously realize (TIL).
So you thought leaving food waste in brine was safe because it would only kill the bad bacteria?
If you read the whole thread, I would not have to spell this out. These are preservatives (source):
- honey
- salt
- garlic
- sugar
- ginger
- sage
- rosemary
- sage
- mustard
- mustard seed
- cumin
- black pepper
- turmeric
- cinnamon
- cardamom
- cloves
- vinegar
- citric acid
- lemon/lime juice
They generally work by killing/repelling/deterring microbes that to a notable extent happen to be of the unwanted variety. Before yesterday, I thought salt worked similarly to the others on that list. Yesterday I learnt that salt is uniquely functions as a preservative due to a different mechanism (a drying effect).
Your logic is nonsense. To claim that because substance X does not kill /everything/, it cannot serve as a preservative – this is broken logic that you brought to the thread. Nothing on that list of food preservatives kills or deters every microbe - not even every harmful microbe. Of course they selectively mitigate /some of/ “the bad bacteria” (but note it’s a bit straw mannish for you to use the article “the” in your phrasing imply /all/ unwanted microbes). Most preservatives mitigate enough unwanted microbes without unacceptable overkill to beneficial microbes to justify use as a preservative. They are selected as preservatives for this reason. Foods that fail to significantly select against unwanted microbes (i.e. most foods) don’t get tagged as a preservative. How are you not grasping this?
You also have noteworthy bad assumption: that evolution does not happen outside of the ocean. The claim that because life started in the ocean, the ocean is therefore suitable for everything – this is bogus. Try putting a freshwater fish in the ocean. If a complex organism can evolve to become intolerant to the environment of its ancestors, why wouldn’t microbes also evolve to develop intolerances?
the main concern from the manufacturer is likely something like salt water sitting on the surface for days at a time over and over while the machine sits unused. any reasonable cook time is unlikely to begin harming the surface of any moderately high grade stainless.
Refill the salt? Like the shakers?
Ah, I wondered if I needed to explain that, since dishwashers in N.America do not take salt. European dishwashers tend to have built-in water softeners (because it’s somewhat uncommon to have whole house water softeners). So we periodically have to fill a salt reservoir in the dishwasher to feed the water softener.
Ah, ok. I was familiar with water softeners needed for homes with well water, but it didn’t occur to me that soft water would be a problem for dishwashers. Thanks!
Well it’s not actually clear to me whether the soft water is to protect the dishwasher, or to make cleaning more effective. Soft water dissolves soap better which makes it more effective in cleaning. It also means I can use powdered detergent (which is cheaper than liquid detergent, but in hard water powder doesn’t perform as well). Soft water has the down side that it’s actually /more prone/ to corrosion than hard water (at least according to youtube plumbers). So I’m tempted to conclude the built-in water softener is just for cleaning effectiveness.
My understanding is that every mole of water hardness (mostly Ca^2+) reacts with two moles of soap to produce soap scum. So using softened water (replacing Ca^2+ with 2Na^+) allows you to use less soap and reduces soap scum buildup.
Yeah. Not immediately, the chromium in stainless steel gives it a good amount of resistance, but if you’re leaving it for days at a time you’ll find the surface becoming pitted as the chlorine reacts with the protective layer.
Even stainless steel will corrode, and salt especially will speed up the process. Solid salt is much worse than salt water, because the concentration of solid salt is 100% vs a fraction of a percent for pasta water. Regardless, leaving salt water sitting in your pot for days on end is definitely going to make corrosion occur faster, although by how much I can’t say.
Although, I will say that needing to buy even one additional pot might offset any environmental benefit from reusing your pasta water. Industrial manufacturing uses a ton of water, so if your goal is to preserve it, you’re likely better off just washing & drying your pot out between uses so that it lasts longer.
I could always transfer it to glass or plastic to protect the pot but I guess laziness was the original motivator. Salt is cheap enough that I’ll probably just toss it going forward.
I can’t imagine it’s particularly food safe to leave your starchy pasta water out for a few days and then reuse it.
In any case it’s far less salty than what could potentially happen in the dishwasher with a relatively large amount of the decalcifying salt and a couple drops of water.
Worst case you can polish and re-passivate your stainless steel cookware, but it shouldn’t come to that.
I can’t imagine it’s particularly food safe to leave your starchy pasta water out for a few days and then reuse it.
I haven’t tested a few days of non-use. It’s usually if I happen to make pasta two days in a row, and (more rare) three days in a row (where it still boils daily).
Grains of salt can likely scratch the surface, which speeds up process considerably.
But generally, i believe, salt water speeds up corrosion due to micro structures in any steel (but its very slow, like 2-3 years of salty water). Also aren’t you afraid something will come to live in 2 days in warm salty water 😱
Also aren’t you afraid something will come to live in 2 days in warm salty water
Wasn’t salt the most popular preservative in the days before refrigeration existed? The stuff boils with heavy salt (like ocean water), so starts off semi-sterile due to the boiling. Then I don’t imagine many things looking for a home in brine, which then boils again the next day. This water is saltier than foods that rely on salt for preservation.
Ocean water is self evidently friendly for microorganisms. I was thinking that brine was saltier than ocean tbh (and long term salt was used dry (?) for fish and meat), but this is more my half memories, if stuff doesn’t grow for you, then its probably fine
Yeah, indeed I just realized from an article I linked that salt only works as a preservative by drying out food. So salt water is indeed useless.
And i should mention, that food safety issue is more connected to toxins from fungi/bacteria, not the organisms themselves. They’ll die at 100 C, but some toxins might remain intact. And after cooking pasta your salty water contains not only salt, but starch (food).
Indeed, that’s a good point. I wonder how many people don’t know that. I used to think “nothing will survive 250°F in my pressure cooker” and was tempted to cook some questionable pork. But yeah, would have been dangerous because chemical toxins from bacteria output would “survive” (persist) in 250°F. So after some quick research, I tossed it.
Though I might be surprised if 24hrs is enough time for brine to not only accumulate bacteria in high numbers but also allow enough time for bacteria toxins to be produced. How fast does that happen? I would have thought a day is too short (I don’t think I ever let more than a day pass between boils).
i think e. coli grow in the lab in like 4-8 hours. Thats obviously in specially designed nutrient soup, and they prolly start from more than couple of spores in the air
Feely wise, in summer if i forget to put soup in fridge it goes bad in like 2 days, so more time than 1 day (and it gets friendly lacto something bacteria, so just gets acidic, not toxic). Fungi starts to grow in like a week.
I think it (whatcha doing) is safe-ish from toxins point (cause 1 day when they grow exponentially in 3-7 days is much less of problem), but still seems sketchy. Toxins are mainly fungi, with bacteria you likely get friendly ones which makes vinegar
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bruh you’re gonna have vinegar scented pasta water lmaoo
Salt-resistant stainless-steel is the 316/316L steels & the 317/317L steels.
( the L versions are low-carbon, which means they can be welded & the low-carbon won’t create carbon-rich defects in the welds )
Salt-resistant aluminum is 5052 aluminum ( low-copper. iirc )
normal cheap aluminum kitchenware is Commercially Pure aluminum, not alloy.
I’ve no idea what percentage of aluminum food-contact things are made with alloys, but it wouldn’t be that much, I don’t think?
Nobody bothers using those salt-safe alloys for making kitchen stuff, because there’s no market-pressure to do-so.
( those stainless steels are costly, & 5052’s used mostly for boats/marine/nautical stuff )
Therefore, using salt in the other alloy bowls/pots/pans does release metals ( including nickel or/and chromium ) into one’s diet or/and ecology.
I won’t add salt to normal “stainless” pots or pans because of that: it can get added after, even-though that’s a harsher taste.
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