Solventless refers to a method of cannabis extraction that does not use solvents, often involving heat and pressure (as in rosin) or ice water (as in bubble hash). For instance, a297. Solventless: Solventless refers to a method of cannabis extraction that does not use solvents, often involving heat and pressure (as in rosin) or ice water (as in bubble hash). For instance, a user might say, “I prefer solventless concentrates for their pure flavor and natural extraction process.” The development of solventless extraction methods reflects the ongoing innovation in cannabis concentrate production, offering a natural and chemical-free alternative to solvent-based extraction.