Home & Garden Home How to Keep Berries Fresh for a Week (Video) By Jerry James Stone Writer California Polytechnic State University Jerry James Stone is a food blogger, vegetarian chef, activist, and internet personality who started writing for Treehugger in 2004. our editorial process Twitter Twitter Jerry James Stone Updated October 11, 2018 ©. Jerry James Stone Share Twitter Pinterest Email Home Sustainable Eating Pest Control Natural Cleaning DIY Family Green Living Thrift & Minimalism © Jerry James Stone In this video I explain how to best store fresh berries like raspberries, strawberries and blackberries so they do not mold. Or at least not anytime soon! With this method, the berries should stay fresh and plump for five to seven days, on average. Up to ten days for strawberries.