3

A week ago, I left soup simmering in my new Staub cast-iron pot (http://www.williams-sonoma.com/products/2507416/) for too long, and all the liquid evaporated and what was left burned on the bottom. I've scrubbed and soaked in hot water overnight for a week but there are still black, charred remains stuck to the bottom (see photo).

My questions:

  1. Based on the photo, can you tell what is on the bottom? Is it burned food, or the enamel, or "seasoning" (I've never seasoned it myself...), or rust, or something else?
  2. How do I clean and restore my precious pot to full health?

my cast iron pot I burned soup dry in

Big Dogg
  • 133
  • 1
  • 5
  • Do you have a self-cleaning oven? – Jolenealaska Oct 24 '16 at 04:15
  • I don't have a self-cleaning oven unfortunately :( – Big Dogg Oct 24 '16 at 05:05
  • http://cooking.stackexchange.com/questions/7127/how-to-clean-a-burnt-cast-iron-pot?rq=1 – paparazzo Oct 24 '16 at 05:15
  • If you're sure it is food burned *on* to the pot, and not the seasoning itself being scorched - I would just cook with it. If it's not coming off with a scrub and soak, it's not coming off into the food, at least not easily - and even if it did, it doesn't look like much and it's likely sterilized by the repeated cleaning. Over time it will either wear off slowly, or else be buried under layers of re-seasoning. – Megha Oct 24 '16 at 05:36
  • You are right, the pot being enameled does make a difference, so it's not a duplicate. Reopened. – rumtscho Oct 24 '16 at 14:55

4 Answers4

4

As this is an enameled pot, there is a difference to "standard" cast iron. First, if you really damaged the enamel, you cannot restore it. You can continue using it, but you'll have to deal with rust. From the picture, I cannot tell if that's the case - some spots are rust-colored, but they could be organic residue burnt onto the enamel.

Second, in trying to clean it, you cannot use the typical cast-iron methods for renewing, which are intended to strip the seasoning so you can rebuild it. So no self-cleaning ovens, no lye baths, etc. You have to treat it like stubborn dirt on semi-delicate surface.

The enamel can take some amount of rough physical treatment, but it has easier time withstanding chemical methods. So I'd try soaking it for a few hours with an organic acid, for example liquid citric acid. Alternatively, soak in dissolved dishwasher powder, that's quite aggressive as detergents go (but not a tab since the finisher in it will counteract the detergent). The Americans here are probably going to suggest Barkeeper's friend, I have no personal experience with it.

A short boil after the soaking can sometimes be quite good. You can use your acid solution (it should be on the bottom only, so no danger from spilling over anyway) or fill some clean water. Then let it boil vigorously for a couple of minutes. The water bubbles tend to be effective in dislodging softened pieces of char.

You can scrub after the soaking, it will work better than without the soak. I wouldn't go as far as taking steel wool to enamel, but the plastic net equivalents should be OK. The rough side of a dish sponge is also OK. The use of abrasive cleaners like Cif is somewhat questionable, you might try them in a low concentration if you don't succeed with other methods.

It is possible that you have either naked spots which have rusted over, or that your dirt is so baked-on that it doesn't fall even with quite a bit of elbow grease. I'm not sure how to tell you to recognize the difference if the char happens to be reddish-brown - I guess I would call rust harder and scratchier than char. If you try cleaning it once and don't succeed, it is still worth it to try it with 3-4 more soaking cycles, with maybe 15 to 20 minutes of scrubbing every cycle (if you see some progress being done during that). These types of burn-on are very difficult to clean.

rumtscho
  • 134,346
  • 44
  • 300
  • 545
  • Thank you very much for your detailed suggestions, including the one that ended up solving my problem (Barkeepers). Your answer is the most detailed and the most helpful for problems like these, I think, but I accepted the one explicitly mentioning Barkeepers and the green side of the sponge because that's what solved my particular problem. But thank you very much for being so clear about the difference between enamel and non-enamel cast iron and for spelling out a variety of methods. – Big Dogg Oct 29 '16 at 06:51
2

You've got some good advice already. I would add, try Barkeeper's friend and scrub the pan with the green abrasive side a scrub sponge (like Vileda).

MirekE
  • 156
  • 2
  • Thank you for the suggestion! I just did this and it *completely fixed my pot*. I have rarely felt such satisfaction, relief, and gratitude using a product. – Big Dogg Oct 29 '16 at 06:49
2

You can try this, but it's not guaranteed to work.

Get it hot, really, really, really hot.

Dump 2 - 3 cups of long grain rice in it (uncooked) and start tossing it like you would if you were making fried rice (off the flame). You're using the rice as an abrasive here, you can't use a gritty sponge with that much heat :)

Add a cup of hot lemon juice along with a squirt of washing up (dish) soap, and keep tossing it. If it's working, you should start seeing streaks through the burned on fonde. If that's the case, keep tossing.

I can't think of any other way to do it that doesn't stand a chance of ruining the enamel coating. Consider investing in some ceramic coated cast iron for stews and such, which is delightfully easy to clean when unfortunate things happen.

Tim Post
  • 4,084
  • 1
  • 24
  • 39
  • I've done this to get mishaps out of seasoned woks, it _just_ might work here. You lose the seasoning, but you save scuffing them all up with harsh abrasives. – Tim Post Oct 24 '16 at 18:35
  • Thanks for the advice! What do you mean by "tossing" the rice exactly? – Big Dogg Oct 24 '16 at 19:53
  • @BigDogg [simple pan tossing](https://www.youtube.com/watch?v=k2UK1iGWlzs) (it's a video link). – Tim Post Oct 24 '16 at 20:12
  • I see... I have a pot, I guess I could do something similar, but it's much heavier and would need to use two hands. Would that be more or less the same? – Big Dogg Oct 24 '16 at 21:33
1

Take a lemon and pour it's juice on the pot, mix detergent in hot water and rub it with sand paper, this might help you cleaning the pot 80 or 90 percent, but as it looks that pot has also rust on it, so washing it for 3-4 times might clean it completely. This technique helped me to clean my frying pan.

lazyborg
  • 31
  • 4