How can you tell if a homemade liqueur has gone bad or spoiled?

Expanded Explanation

A spoiled homemade liqueur often shows visible, aromatic, or textural warning signs. Cloudiness in a liqueur that was previously clear, floating growth, fizzing, pressure buildup, sliminess, or mold around the neck or stopper all suggest contamination or instability. Any of these signs mean the bottle should be treated with caution and usually discarded.

Smell is another strong indicator. A good liqueur may evolve over time, but it should not smell rotten, sour in an unexpected way, musty, yeasty, or unpleasantly fermented unless that character belongs to the recipe. Sudden harshness, off-notes, or a strange separation that does not remix can also signal that something has gone wrong.

Taste should only be checked if the liqueur looks and smells normal. If there is any doubt, do not sample it just to test it. Good hygiene, sensible alcohol strength, full straining, and correct storage dramatically reduce the risk, but learning the warning signs is still important for safe home bottling.