1, uncooked crabs: due to insufficient steaming crab time, the crab is not fully cooked, there may be crab paste bitter, can be put back into the pot for a period of time, the crab is thoroughly cooked before eating, there is no problem.

2, sick and dead crabs: due to crab disease or crab has died, resulting in some changes in the crab body, causing the crab yolk bitter, this crab yolk can not be eaten.

3, environmental pollution: due to the survival of crabs in the water quality, there may be some chemical toxic substances, etc., resulting in crab yolk bitter, can not be eaten.