Yes or you can put the cob in a freezer bag then into the vac bag for two weeks.I have done it both ways.I think going into the vac bag in sweat make the process start quicker.But either way will work i think.The sweat is very important.If your at a good temp you will see some moisture buildup inside the bag during the process.Peace pleaseOne question, is the vac bag sealed for that first 24 hour sweat?