In the fall, the climate gradually changes from cool to cold, and the crabs grow stronger. The digestive glands and ovaries of female crabs grow into crab roe in preparation for winter and reproduction in the coming year (crab roe becomes crab roe in spring). At this time, when you peel off the crab shells, you can see a lot of yellow, sticky stuff among the shells and lumps of crabs, which is the raw crab yolk. When cooked, the crab yolk turns red, and the darker the red, the stronger the crab. Male crabs also gradually accumulate fat in preparation for winter and grow into crab paste (commonly known as crab oil). When you peel off the shell of a male crab, what you see in the same place is white, sticky stuff, which is crab paste (crab oil). When cooked, the crab paste becomes translucent. The more crab paste there is, the stronger the male crab is.

Crab roe and crab paste are not only delicious, but also nutritious, which is the essence of crabs.

In the wild, by the ninth month of the lunar calendar, the crab yolk of female crabs grows the most plump; by the tenth month, the crab oil of male crabs grows the thickest. Therefore, in the past to eat crabs, there are "nine female and ten male" said. Meaning: the lunar calendar in September to eat female crabs, the lunar calendar in October to eat male crabs.