A sprouted garlic bulb.
Why Does Sprouted Garlic Taste So Different?

NEWS

By ELIAS NASH
Garlic that has been sitting in your kitchen for a while might have green stalks sprouting from its center, but rest assured, there is nothing dangerous about these protrusions.
This happens because the levels of antioxidants in garlic increase as it sprouts. From a cooking standpoint; however, sprouted garlic can pose an issue, as it has a bitter flavor.
The sprouting process triggers a chemical change that reduces the garlic's natural sugar level and makes the clove itself bitter. But sprouted garlic is not a lost cause.
In dishes that only call for a clove or two, you probably won't taste any difference, but if you're making a dish where garlic is a primary flavor, use un-sprouted cloves instead.
To avoid getting sprouted garlic, store garlic bulbs whole, as they spoil faster when the cloves are separated, and choose a cool, dry storage space, away from any sunlight.