If you just pulled your Jello out of the refrigerator and freezer and want to know if it has spoiled, there are a few ways you can tell if it’s gone bad. One is to look for pockets of watery liquid. You might also notice that the Jello tastes sharp and bitter. Other telltale signs include the appearance of dark mold or pale bacterial marks. Any time you notice these, toss them. There are plenty of health risks associated with eating spoiled food that is probably best to avoid.