When purchasing, you can refer to:
First, pinch it with your hand. Usually, pure auricularia auricula has less water content and is easy to crush by hand; Pinch it and put it away, and the fragments can be well stretched and elastic. However, the soaked auricularia auricula contains a lot of water and is not easy to crush.
Second, try again with your mouth. Good fungus tastes pure, not only has no peculiar smell, but also tastes fragrant. Inferior black fungus is different, the fragrance can't be tasted, but it has a strange smell. Not to mention toxic and harmful, just saying "delicious" is not enough.
Third, you can buy less and use blisters first. The inferior auricularia auricula soaked in ink will smell of ink, and it can still be smelled if you smell it carefully. In addition, when dealing with auricularia auricula, it is indispensable to use water to make hair. If you find that the water soaked in fungus turns black, don't eat it. Black fungus will not fade. If so, prove that it has been dyed with ink or other pigments.