What is the standard of food appreciation? How to become a professional food connoisseur?

You should constantly accumulate the experience of "taste". If you eat too much, you will know whether it is good or bad. For example, if I give you a dish, you will find that the same dish you have eaten before is tender or crisp, and so on. Naturally, you can tell good from bad. But everyone has their own preferences, such as: sweet in the south and salty in the north, spicy in the east and sour in the west. "As the saying goes," it's hard to adjust ". So it's hard.