It's time to add the alcohol after that. To ensure a uniform flavor distribution, gradually add your preferred rum or spirit to the gelatin mixture, making sumbmre to fully mix. Pour the mixture into bear-shaped molds, which are available online or at most kitchen supply stores. After letting the molds sit at room temperature for approximately half an hour, place them in the refrigerator for a few hours to ensure they set completely. Having Fun with Your DIY Rummy Bears.