Something I've always been curious about.

I consider myself to be a decently proficient cook, and at the same time, an equally proficient scientist. But one thing I can't really grasp the concept of.

There are many ways to season a cast iron skillet. Personally, I've always used either Crisco or vegetable oil. But I've heard that a lot of people like to use rendered bacon fat. In college, I used to render bacon fat and save it in a glass in the fridge to use for cooking (the only cooking fat better is duck fat, delicious). But I always kept the rendered fat in the fridge, and used it within fairly reasonable time.

So, to get to the point. If you season a cast iron skillet with bacon fat, how does the fat not go rancid from sitting around at room temperature for days, weeks, or even months before being heated up again?

a reply to: Schmidt1989

I am thinking because of the salt,when treating a skillet,salt it and toss it in the oven for a bit with a bit of oil or in this case bacon fat...might be the salt.
I always keep my bacon fat in a can on the counter.,no issues.

When creating the coating you are doing a chemical reaction. Bacon grease works fine. In fact to reseason the pan, just fry bacon occasionally. Tomato stuff is hard on that coating, We have four different sized cast iron frying pans we use on a daily basis, and many more to use outside on the firepit/grill. Another important thing is not to overheat them. I haven't had to reseason a frying pan very often since I did some research on what causes the breakdown of the seasoning.

My grandmother always told me to wash the skillet ans then use olive oil.

Mouse is correct here, you have created a chemical reaction that changes the structure of the fat by carbonizing it so that it bonds to the iron. Only excessive heat or soap/detergents will break the bond---thus the old saying that only sand and water should be used to clean cast iron utensils.
I have cast iron pots, pans, skillets and a Dutch oven used by my great-Grandma. They have always been seasoned with bacon drippings or lard.

a reply to: Schmidt1989

I have always used cast iron and I have always cleaned it with salt and then dried it on the stove. When hot, I would wipe it with lard to keep it season.

I still do that but I have discovered a new way of seasoning cast iron, that works beyond belief.

Google - seasoning cast iron with organic flax seed oil (same as linseed but edible) and follow the procedure.

Tired of Control Freaks

a reply to: Schmidt1989

Yes, as with any cooking utensil that has oil on it wash before using. The oil/fat will oxidize and also allow dust and anything else in the enviroment to contact it and possibly adhere to it.
Many people get all weird about "seasoning" when I restored all of my current stock of skillets I first baked all the old crude, left by the previous owners off using the self-cleaning setting on my oven, then seasoned each one with vegteable oil. They all turned out clean, crude free and, to this day, remain shiney (I live in Cocoa Beach Florida and keep my house open to the humidity and salt air a lot ).

All my skillets and pans hang on a rack in the kitchen
I have some stainless ones. They are all old style Farberware (good stuff).
The cast iron skillets are my favorites: A few big letter "GRISWOLD"s, one "Good Health Skillet" and a couple of "WagnerWare".
The most versitile one is my "GRISWOLD 8 777 CHICKEN PAN" a deep skillet with thin sides and bottom. excellent for corn bread!
All the iron ones are old U.S. Made from the 20s through 50s. The craftmanship is remarkable, especially the GRISWOLDs!
The bottom line. Do what you want, seasoning and cleaning wise.
But never...........
1. put a cast iron skillet in a dishwasher.
2. Put cold water on a hot skillet. (Crack! and/or Warp!!)
3. Test for skillet "hotness" with your tongue.

i cook quite a bit of stuff in my cast iron skillet. Fatty stuff.

I also use it for cornbread.

I seasoned it with bacon fat. I wash it with a brush and hot water. No soap. Never soap.

And my bacon grease sits in a metal cup (like from a soda fountain) on my counter top, next to the stove. But we use it quite a bit.