Why shouldn't you rinse an iron wok with water right after cooking?

Foods not suitable for cooking in an iron pot
While iron woks are useful and nutritious, using them to cook certain foods can destroy the nutritional value of both the wok and the food itself, turning the resulting dishes into "poison."
This isn't meant to scare anyone; it's based on scientific evidence. Chefs who cook regularly pay close attention to this, and we hope that ordinary people will learn from them and use iron woks correctly.
Acidic foods are not suitable for cooking in iron pots. For example, foods such as tomatoes, sauerkraut and hawthorn that we often eat will damage the material of the iron pot.
Acidic foods contain fruit acids, which react with iron to form harmful substances.
Excessive iron ions that overflow from the pot can put an unnecessary burden on the internal organs when they enter the body along with the food.
Some people experience nausea or abdominal pain after eating these types of foods; this is a bodily reaction.
If you don't pay attention to it for a long time, it can easily cause unnecessary problems for your body.
Therefore, acidic foods are best prepared using stainless steel pots or other pots that will not interfere with the food itself.
Mung beans are not cooked in an iron pot.
Many people keep things simple at home, and they only prepare one pot for cooking, using an iron pot for everything.
Actually, that's not right. For example, mung beans, which we often eat, are not suitable for cooking in an iron pot.
The flavonoids in mung beans react with the iron pot, resulting in a dark black color in the cooked mung beans.
This is the effect of the combination of the two; it has turned nutrients into harmful substances.
Eating this type of mung bean all the time can lead to gastrointestinal discomfort or even other diseases.