I blew my friend Amy’s mind with this trick last week. Basically, you can massively extend the life of your herbs and salad greens by replacing some of the oxygen in their storage bag with carbon dioxide. You can either squeeze the air out, or if you want to be really thorough you can use your mouth to inhale it. Then just fit the bag over the nozzle of your Sodastream and add a few puffs of CO2 before sealing it off.