Beans do get softer the longer you cook them and if you cook the beans too long it can lead to them becoming too soft and mushy and even fall apart.
Overcooked beans don't get hard and instead overcooked beans become soft and mushy and even can fall apart as the prolonged cooking of the beans break down the cell structure of the beans which makes then very tender and lose their desired texture.
When the beans are very soft and almost mushy they are overcooked and when the beans are still hard or crunchy it means the beans are not fully cooked.
Undercooked beans are hard and when your beans are still hard they should be cooked longer until they soften.
Once softened they are fully cooked when they can be easily mashed with a fork.
You can speed up the cooking time of the beans by soaking them in water overnight and they will cook faster the next day.
Some beans take 1 hour and some beans take 2 hours to fully cook.
When beans are cooked and ready to eat the beans should be soft enough to mash with a fork against the side of the pan without much resistance but not too soft where the beans become too mushy.
When the beans are fully cooked they should be tender, soft and easily mashed using a fork and you should be able to squish them with the fork without too much resistance.
If you eat the bean it should be soft with no hard or grainy texture and easy to chew.
If the beans are not easy to squish or are still hard then they require further cooking.
Eating crunchy beans is generally okay although when you eat crunchy beans that are not fully cooked you can possibly get lectin poisoning, especially if you eat too many of them.
I've eaten some undercooked beans and crunchy beans before and didn't get sick but there's a possibility of getting sick from them so it's best to fully cook the beans until they are soft to prevent the possible lectin poisoning.
The food poisoning you can get from beans is a food poisoning called phytohaemagglutinin poisoning also known as lectin poisoning.
Lectin poisoning from beans can occur when you eat undercooked beans or raw beans due to the toxins that are contained in the beans.
Many beans contain the natural toxin phytoaemagglutinin which is removed when the beans are fully cooked.
Lectin poisoning is a type of food poisoning that is caused by consuming lectins.
Lectins are proteins that are found in plants which can be harmful to humans in certain circumstances.
Symptoms of lectin poisoning include stomach upset, diarrhea, vomiting and nausea.
Foods that contain the lectins include wheat, castor beans and kidney beans.
Wheat lectin can have negative effects when consumed in high concentrations or when consumed raw.
Castor beans contain ricin which is a potent lectin poison.
Kidney beans contain phytohaemagglutinin which is a lectin that can cause your red blood cells to clump together.
Eating kidney beans that are raw or undercooked can cause lectin poisoning.
The lectins can also cause changes in your stomach and intestines including denudation and epithelial cell necrosis.
Lectins can also bind to the walls of your digestive system and can cause increased permeability, leaky gut syndrome and seeping bowel syndrome.
Most lectins are not harmful to humans and many foods that do contain lectins are a good source of nutrients.