A mild smell may mean your ginger has spoiled

When ginger has gone bad, the root will give off a few telltale indicators that it's time to throw it out. If it's been more than a few weeks on the counter or a few months in the fridge or freezer, you should perform a visual and olfactory assessment before using it in your recipe. The ginger's exterior layer should be papery, while the core should be firm and yellow. Ginger that is soft, wrinkled, or has visible mold growth has gone rotten.

If your ginger passes the visual examination, you should also take notice of its fragrance and flavor when using it. According to Fresh From the Gardens, low-quality or rotten ginger will not have the same strong flavor or scent. It is okay to consume ginger that is bland but not moldy (though it might not be as fun). Expect no vivid pops of flavor in your stir-fry or drink.