Some people are taught from childhood that it is not customary to leave a spoon in a bowl with prepared food.
Others may forget or see nothing wrong with the habit at all.
In fact, you shouldn't do this for various reasons. First of all, it's worth noting that such food starts to spoil much faster.
This is especially important in the summer, since the shelf life of any prepared food is significantly reduced.
There is also an opinion that leaving a spoon in food can cause deterioration of the digestive system and even lead to poisoning.
The thing is that the spoon is made of materials that have the ability to oxidize. Because of this, the chemical composition of the food may change.
Also, do not forget that there are harmful microorganisms on the spoon. When they get into food, the process of its spoilage accelerates. For the same reason, the risk of poisoning increases.