Spoiled stock often exhibits a sour or off-putting smell, a cloudy or discolored appearance, and may contain mold or excessive bubbles. These are clear indicators that the stock is unsafe to consume.
Determining if stock has spoiled involves assessing several key characteristics. Here's a breakdown:
Smell: This is often the first and most obvious indicator. Fresh stock should have a mild, savory aroma. Spoiled stock will have a distinctly sour, rancid, or otherwise unpleasant odor. Trust your nose; if it smells 'off,' it probably is.
Appearance: Examine the stock's color and clarity. Fresh stock is typically clear or slightly opaque, depending on the ingredients. Spoiled stock may appear cloudy, discolored (e.g., greenish or gray), or have a slimy texture.
Mold: Check for any visible mold growth on the surface or around the edges of the container. Mold is a definitive sign of spoilage.
Bubbles: While some bubbling can occur naturally during the cooking process, excessive or unusual bubbling, especially after the stock has been refrigerated, can indicate bacterial activity and spoilage. This is particularly true if the bubbles are accompanied by a foul odor.
Taste: If the smell and appearance seem borderline, a tiny taste test (a very small amount!) can help. However, if you have strong suspicions of spoilage based on smell or appearance, it's best to err on the side of caution and discard the stock. A sour or 'off' taste confirms spoilage.
Remember that commercially prepared stock in sealed containers should be used by the 'use by' or 'best by' date printed on the packaging. Once opened, it should be refrigerated and used within a few days. Homemade stock typically has a shorter shelf life than commercially prepared stock.
To extend the shelf life of homemade stock, cool it rapidly in an ice bath before refrigerating or freezing. This prevents bacterial growth and helps maintain its quality. Divide the stock into smaller portions before freezing for easier use later.