Answered by Zhong Kai, Associate Researcher at the Department of Risk Communication, China National Center for Food Safety Risk Assessment: The "white fluff" growing in vinegar is most likely a Kahm yeast film produced by Mucor. Mucor is widely found in the environment and thrives in high temperature, high humidity, and poorly ventilated conditions. Mucor has a wide range of uses in the food industry, such as for starch fermentation, decomposing soy protein, and making fermented bean curd and douchi. However, these are specifically selected strains that do not produce toxins or cause disease. If the white fluff in the vinegar is solely caused by Mucor, removing the Kahm yeast film and continuing to consume it should not be a major issue. However, there are other pathogenic bacteria in the air that, if they also multiply in the vinegar, could pose a health threat. Therefore, it is best not to continue consuming vinegar that has grown white fluff.
To prevent vinegar from growing mold, pay attention to the following points:
1. Always cover the vinegar container tightly during storage, especially after use, and store it in a cool, low-temperature place to avoid contamination from airborne microorganisms.
2. Choose a container size appropriate for your family's consumption. For larger families, a large barrel or bottle of vinegar is suitable. However, for a small household of two or three people, a small bottle is sufficient to avoid prolonged storage.