zuò / mù sī dàn gāo / de / shí hou / xū yào / xiān / yòng / lěng shuǐ / pào ruǎn / jí lì dīng做慕斯蛋糕的时候,需要先用冷水泡软吉利丁。When making mousse cake, you need to first soften the gelatin in cold water.