I love, love, love having sour cream on hand. It's so versatile! I like buying the larger tubs, but hated having to throw out half of it when it went bad before it's expiration date. Once I opened it, it seemed like it started growing black spots immediately. Turns out, there's a trick to keeping it fresh longer. Only use a clean spoon dedicated to scooping and then smooth out the surface with the back of the spoon before putting it back into the fridge. The dips and divots in the surface collect moisture in the fridge and that's what causes it to start growing mold. Try it!