Milk which will not be made into butter must be made into cheese.

When something cannot serve the purpose first intended for it, it should be redirected to another worthwhile use rather than discarded. The saying favors practical adaptation and making the best of available resources.

It can also urge acceptance of a changed plan: failure in one process need not mean total loss. A person should identify what remains useful and reshape it into an achievable result.

Use this proverb when advising someone to salvage value from an unsuitable material, failed plan, or disappointing outcome by choosing a different practical purpose. It suits discussions of resourcefulness and changing course.