1. Look at the color and shape of the pleats. The pleats of crimini mushrooms are thicker and slightly silver-gray in color, while crimini mushrooms in some areas are slightly yellow.2. Pinch the stalk of crimini mushrooms. The stems of crimini mushrooms are solid and firm when pinched, without a hollow feeling. 3. Look at the color of the cap. The middle part of the cap is dark red or dark purple, but the surrounding color is lighter than the middle part.4. When you look at the color in the water after soaking, the crimini mushroom itself will fade to a rose-red color. But the color is slow and uneven in the process of spreading. And the infected fungus will turn red quickly. Extended information:Red mushroom is a kind of large mycorrhizal fungi, which is a kind of precious wild edible fungi. It is widely distributed all over the world. In China, it is mainly distributed in Fujian, Yunnan, Jiangxi, Liaoning, Henan, Sichuan, Guangxi and other provinces, with an altitude of 300~1000mm, and a vertical distribution of vegetation and soil, with a gradient of 10~45° from gently sloping to sloping. Most red mushroom varieties are edible. Red mushrooms not only have a unique flavor and taste, but also have a very high nutritional content. Red mushrooms contain protein, carbohydrates, minerals, vitamin B, vitamin D, vitamin E, essential amino acids, polysaccharides, copper, zinc, iron, manganese and other essential trace elements.