Keeping food warm: does cast iron make a suitable potluck vessel? I'm making this hash recipe for a potluck at work tomorrow.

Tonight I did all my prep:


Peeled, diced, roasted the sweet potatoes
Diced the  onion
Diced the apples (stored in water w/lemon juice)
Cut the bacon into lardons
Sliced the green onions


So tomorrow morning should be a strait-forward "pluck from the fridge, heat it all up" affair.  I was initially going to do this in a big saute pan but am now considering using my lidded cast-iron fryer.  Basically when the hash is near done, I could just put the whole lot into a bag (w/proper heat protection, of course) and head to work.

My questions are:


Will the reactive qualities of cast iron be undesirable for this type of "longer term" food storage/serving?
Will the hash actually stay warm for the 2.5-3 hours I'll need it to?


If anybody has better tips for keeping a hash-like dish warm long enough for a lunchtime potluck, I'll take em!
All the cast iron pans I've got came with instructions that read along the lines of "suitable for serving, but not storage of food".

I'm not sure what would suffer most though, your pan, or the food, or both, depending on length of time. My guess is that the length of time you actually can store food in a cast iron pan/pot safely somewhat depends on the ingredients used. For example, a tomato sauce would be less good to store in a cast iron pan than fried potatoes.

Regarding the temperature, I'd say it depends on how well insulated your "bag" is. Cast iron distributes temperature very nicely, but that doesn't necessarily mean it will cool less quickly than another type of pan (of same size/thickness) when taken off the heat.

Regarding keeping food warm, I did see insulated pots similar to a thermos flask you'd use for hot coffee or tea, which are made to store food. They have a big enough opening to be filled, and to be eaten from.