As part of our Bong and Rig rental program, we are adding a Rosinbomb Rocket to the program. Spend $300 to foster it for 3 days or rent for $20 a day. Press Flower, Kief into Rosin.Rosin is a solventless cannabis extract that is made by applying heat and pressure to cannabis plant material. It’s a popular method among enthusiasts looking to create a pure product without using solvents like butane or CO2. Here’s a general guide on how to make rosin using a rosin press: