How long does the fish glue usually stew: 30 minutes to 3 hours. The stewing time of gelatin is related to the size and age of gelatin. The smaller the gelatin, the easier it is to cook. The smaller the gelatin, the shorter the stewing time. Generally, Ejiao with a small head and a small year can be cooked in about 30 minutes to 1 hour. However, if the gelatin is large or old, the stewing time will be longer, which may take about 2-3 hours or even longer. There are also different varieties and different meats. Some fish glue is small, but it is resistant to stewing, but it is relatively rare.