Many people save money by purchasing a large block of rosin, especially those who play the cello professionally. If you play regularly, I recommend investing in a larger block, but bear in mind that there is a shelf life. Typically, rosin lasts between six months and two years. You can extend the lifespan of your rosin by making sure it is properly sealed. Professionals who buy blocks of rosin will likely have to store it in a large, airtight container.