I'm trying to cook some dried corn that normally is meant for popcorn.
I've soaked it 36 hours using bottled water and then rinsed it multiple times with tap water.
After that I cooked it for about 1 hour, yet the corn is still hard? What do I do?
Popcorn does not soften.
There are five main types of corn: dent, sweet, flour, and popcorn. These types vary slightly in their composition but they share a similar basic structure:
Dent corn is used almost exclusively as animal feed. Incidentally- it is the only type that I ever saw for sale in Germany which might explain why all the Germans I met thought we were crazy for eating corn on the cob.
Sweet corn has a soft hull and much more sugar in the endosperm- It is eaten as whole kernels.
Flour corn has a couple delicious starches in the endosperm and a manageable hull. Manageable in the sense that it can be ground to release the starches.
Popcorn is unique in that the hull is freakishly thick and not porous. When the popcorn is heated the steam inside the kernel forces the hull to shatter- releasing the steamed starches which instantly solidify in the air.
The hull is made out of cellulose and is indigestible to humans and insoluble in water unless treated with inedible amounts of acid (or acetone). Boiling popcorn might partially rehydrate the interior starches but it won't soften or remove the hull.
Popcorn can be ground into a course corn meal. In this case the starches are mechanically liberated for our polenta or cornbread enjoyment.
I have never heard of boiling popcorn and was intrigued that @rumtscho said that she had seen it. The only single reference I was able to find online for boiling popcorn was to make parrot food. This website at least recommends cooking the corn in a slow cooker for 10 hours. This is in line with times for cooking whole wheat berries. You might give it a try.
You can do it. My family has done it before, and I like the outcome. The texture is not the same as with vegetable corn, it is mealier, and the outer skins are much tougher. It is up to you whether you like it.
And for substitution, I don't know what is available where you live, but around here canned corn kernels are really cheap and available all year round. They are just cooked kernels, maybe some salt, nothing more. Pour out from the can into the casserole (maybe drain first) and you are done.
Hard corns can be cooked the way native peoples cooked it. If it is dry then you must 'lye' it first. This is done by putting wood ash ( about 2 cups) from fully burned hard wood into a big pail of water . Strain the lye water into a cooking pot. Boil your corn kernels gently for about an hour. Thoroughly rinse the corn free of lye water. Now you can prepare the corn whatever way you want.
The corn must be freshly picked and undried to cook without 'lye-ing' it first.
Not really: popcorn is made from a special variety of corn which has very low moisture, and is very dry and hard. Corn meant to be eaten as whole kernels (as oppposed to ground into meal, or as popcorn) comes from sweet corn varieties, which are not suprisingly, higher in sugar, and harvested prior to their drying.
Instead, you want canned or frozen corn kernels.
People, people people! If you don't have slaked lime, or don't want to burn your arms off with slaked lime, then just substitute BAKING SODA.
All you need to make hominy is an alkaline solution, which you can make by mixing any alkaline powder (like baking soda, quicklime or slaked lime -- or "cal" in Spanish) in boiling water. The effect of an alkaline solution is to break down the cell wall in the cells of the dried corn (since those cell walls of plant cells are soluble in an alkaline solution), which makes the corn kernals soft and the husks loose so you can remove them.
To make hominy with baking soda, use proportions of 2 to 1 water to dried corn, and use 2 tablespoons of baking soda for every quart of water. I do the boil-and-wash thing twice to make sure they're good and soft and all the pieces of husk are off. Don't forget to prepare the dried corn before this process by soaking it in water overnight.
If you are trying to make Pennsylvania Dutch style dried corn, be aware that this is dried sweetcorn, and not a hard corn like maize, dent or popcorn. It was a popular method of preserving sweetcorn before the advent of freezing and canning, and the dish remains popular to this day because the reconstituted corn has a significantly different flavor, robust and nutty, that makes it suitable as a winter dish.
You can dry sweetcorn yourself in a dehydrator, warm oven, in the sun (pdf) or a smoke-house (for a New Mexican twist on the dish), or you could purchase it online from John Copes, which has been in the business of drying sweetcorn for more than a century.
I cook dried corn with wood ashes at a 1:3 (One part ash and 3 parts corn) in a pressure cooker for about 40 minutes. It works great. Then thoroughly rinse.
I also cook the dried corn with wood ashes by boiling the corn for one minute and then keeping it in a insulated box for 12 hours. It's usually self cooked soft. If not boil it once more for one minute and return to the insulated box for a few more hours.
You can try doing it like the Native-Americans and use Lime (not the fruit).
There are different types of corn. Maybe you are using the corn for popcorn; that won't do it. You need the kind of dry corn for boiling: that won't take that long to cook.
Cook it in a pressure cooker for 40 to 50 minutes.