Mamacity says: I took my 37-year-old sourdough starter out of the freezer and fed it. It’s still bubbling after all these years. When I stopped baking bread for local restaurants, I started keeping my starter in the freezer, taking it out and feeding it mostly before holidays or reunions. I last used it for Thanksgiving 2021. If you treat it right, it will never go bad, and the older it gets, the better it is. Kind of like. . . us.