Garlic clove has turned to a firm jelly texture

The green in the center can have a bitter taste, and many chefs prefer to remove them. If the taste and color don't bother you, it will not cause problems for the dish.

The brown end tends to a have a harder consistency than the rest of the clove, so may cause a problem depending on how you cook the garlic. If you're cooking it in a manner that leads to a very soft and mushy piece of garlic, you'd be better off discarding it. (Boiling in soup, for example.) It probably would not make much of a difference if you were browning the garlic for a topping.

There are three signs you want to look for on garlic that indicate you may not want to use it:

1. Signs of mold, especially black mold. Discard the garlic.
2. Soft to finger pressure. It is rotten. Discard.
3. Sprouted. While it is still safe to eat (if it doesn't have other issues), it may be bitter.

Good garlic should be quite hard when pressed with your fingers, and preferably is not sprouted. Some people even remove the green core of partially or beginning to sprout garlic when they prep.