Warning: Salting Pasta Water Before It Boils Can Pit Your Stainless Stockpot

[Jim White]

Okay, folks, here's a chance for you to learn from my mistake. My induction cooktop and Misen stainless cookware will be two years old in early November. The joke in our kitchen is that the Misen is "sacred" cookware that I protect intensely. I always wash it by hand.

Pasta dishes are in heavy rotation at our house, and so in the 19 months or so I that I've had the Misen stockpot, I'd guess it has boiled pasta water around 75 times. This evening as I was firing it up for a lazy dinner using fresh tortellini from a bag at the store, I decided to think a bit about why the stockpot is starting to look like the bottom inside surface is starting to pit. Not huge pits like potholes, but more discolorations than anything. They don't show a lot just after washing the pot, but by the time it comes out for the next use they are more pronounced.

Here's a look at the pot just after washing tonight and then again a few minutes later in a closer shot.





Since it's only the stockpot showing this problem, and since the pot is used almost exclusively to cook pasta, I decided to google "can boiling salted pasta water pit stainless steel" or something of the sort. My heart sank when I saw this entry in the results:

If you add salt to your water before it’s boiling, some of the salt will settle to the bottom of the pan, causing pitting to occur.

This hit me especially hard, because I had been vaguely aware that there are arguments between those who claim pasta tastes better when the water gets salted only after it begins to boil and those who say it doesn't matter when you add the salt. I had thought that the argument rested on claims relating to the temperature the salted water boils at and knew that for any given salt concentration, the boiling point will be what it is no matter when the salt went in, especially since we're talking about boiling the pasta for several minutes. So, being lazy, my habit has been to add the salt quite early while I'm waiting for things to get going on the boiling front, partially to scoff at that folks who somehow thought water that had boiled first was somehow better for the pasta. It had never occurred to me that this is bad for the pot.

Sadly, the article states that once pitting begins, it tends to spread. The silver lining, though, is that it also tells us that pitting does not affect the performance of cookware.

So, if you have new stainless (sacred) cookware now or in your future, boil pasta water before salting it to prevent pitting in your stockpot. And don't salt food in any stainless cookware before it gets good and hot.

Edit: Note the nerds having fun in comment 10 below. This prompted further thought on my part that is worthy of adding here. Dave pointed out that the solubility of salt in water is only a few percent higher in boiling water than at room temperature. Then I pointed out that that measure applies to how much salt can dissolve at the two temperatures but now how fast it dissolves. The damage to the pot comes when salt crystals fall to the bottom of the pot before dissolving. Temperature affects how fast the crystals dissolve. But the surface area of the crystal also has an effect (more surface area means dissolving more quickly) as does whether the solution is being stirred. So, for maximum protection of your sacred pot, get the water good and hot, use table saly instead of Kosher (smaller crystals have more surface area) and pour it in slowly while stirring until the water looks clear again instead of cloudy. I know in my laziness I had been grabbing the box of Kosher salt and pouring it into cool water. Sometimes I would see crystals sitting in the bottom of the pot and didn't always stir until it all dissolved. Oops.

[CaptainMike]

Thanks, Jim, great PSA.

[Draznnl]

Thanks for the heads up Jim.

[Mosca]

Count me among those who have always just dumped the salt in. Now I know better, thanks!

[ItsAllGoneToTheDogs]

Thankfully I don't care about our current pots, but really good to know for the next set I might actually care about. To be fair I've always been taught that salt first expedites the time til boil so figured that was the norm.

[captainlee]

I thought that i have heard that before. Luckily we always seem to forget the salt until adding the pasta, so our forgetfulness is working to our advantage. Also chlorine bleach will attack stainless. Thanks for the reminder.

[Michael_in_TX]

Same here.....always forgetting the salt!

[Jessterr]

Sorry to hear of your experience Jim, thanks for the heads up to the board. Upon retirement a few years ago I replaced my worn out ancient pots and pans with quality stainless, having decided to use the free time to put some effort into cooking. The literature that came with the cookware (which I did actually read) explicitly warned about waiting to add salt until after boiling had begun for that exact reason, and while I’ve always adhered to that, at the same time have wondered if it was actually necessary. Well, looks like it is. Hoping you still get many years of service out of that pot!

[jfmorris]

Thanks for the lesson - I’ve got cheap stainless stock pots I use but always add the salt before the boil. I’ll start waiting going forward. In fact I had recently been noticing discoloration in the bottom. Which could be due to this exact reason.

[DavidNorcross]

Never knew this. Thank you Jim.

[DaveD]

Can't argue with actual evidence, but I'm very surprised this would make a difference. NaCl is highly soluble in water, and there is almost no temperature dependence to it. This from a datasheet on the Sigma-Aldrich website (a major scientific supply company):

"Maximum solubility of NaCl in water at 25°C is 357 mg/ml. NaCl is unusual in that its solubility does not increase appreciably with temperature, since at 100°C, the solubility is 384 mg/ml."

In other words, salt is basically just as soluble in cool water as it is in boiling water. The only thing I can think of that would make a difference is that a vigorously boiling pot of water might help keep the salt crystals suspended above the bottom of the pot long enough for it to fully dissolve, whereas if it's still, the salt crystals can reach the bottom and make physical contact with the steel.

A simple experiment would be to take identical pots of water, and in one just dump in the salt as usual, but for the other, stir it into some water in a measuring cup or something until it's dissolved, and add that. I would predict that the latter would show no pitting damage.

Put another way, that's all very well in practice, but what about IN THEORY???

[DaveD]

We're in violent agreement As long as the salt crystals don't touch the steel, all should be well...

[Bkhuna]

I would like to conduct that experiment but unfortunately, after writting the SOP, it would have to go through a committee made up of representatives from Safety, Technical Documents, Cost/Benefits, Logistics and the DEI office before getting the OK. By then, the stainless steel pots would have been replaced.

[DaveD]

Bkhuna At least you wouldn't need Congressional authorization, like we would! har dee har har

[Uncle Bob]

"The silver lining, though,........". Jim White, that's pretty punny, intended or not .

[Jim White]

If you need a clue, I smiled while typing it.

Edit to add: awesome new avatar. Please tell me that's a sign at your place.

[Uncle Bob]

Yep, had that sign and a couple shirts with that logo made up. We're goin' full on amateur semi-pro here........................