Rosin is made by pressing material between two heated plates. No solvent, just heat, pressure and a filter bag.
The variables that decide the result:
- Plate temperature — lower gives a lighter, more aromatic yield, higher pushes out more of it but darker.
- Pressure and time — a few tens of seconds is enough.
- Bag mesh — measured in microns. A finer screen lets less contamination through.
Flower rosin is pressed straight from dried material, hash rosin from bubble hash. The second is cleaner, because the material was already cleaned up before it went in the press.
Cold cure means the finished rosin is left to rest in the cold — it lightens and thickens into a creamy consistency. Hot cure does the same thing warmer and faster.