There’s no reason to freeze formula. Just mix the powder and water—or use premixed liquid ready-to-feed formula—when you need it. Powdered formula should be used within one month of opening the can or tub. You can store a prepared (but untouched) bottle of formula in the back of the fridge for 24 hours. Opened containers of ready-to-feed and liquid concentrate formulas are good for 48 hours. Your fridge should be at 4°C or 40° F.
Have more bottle-feeding questions? Download our chart here and put it on the fridge—it has the answer to all your questions.