Coconut chutney ferments after refrigeration primarily due to the presence of naturally occurring microorganisms like bacteria and yeast, which thrive on the sugars and moisture present in the chutney, even at refrigerated temperatures. These microorganisms produce acids and gases, leading to fermentation and spoilage.
Coconut chutney, a popular South Indian condiment, is made from fresh coconut, spices, and sometimes yogurt or lentils. These ingredients naturally harbor microorganisms. While refrigeration slows down microbial activity, it doesn't completely halt it. Here's a breakdown of why fermentation occurs:
Microbial Growth: Bacteria and yeast are present in the raw ingredients. Even after grinding, these microorganisms survive.
Sugar and Moisture: Coconut contains natural sugars, and the chutney has a high moisture content, providing an ideal environment for microbial growth.
Temperature: Refrigeration slows down the growth of these microorganisms, but some can still thrive at low temperatures, albeit at a slower rate.
Acid Production: As the microorganisms consume the sugars, they produce acids (like lactic acid) and gases (like carbon dioxide), which cause the chutney to sour and ferment.
Lack of Preservatives: Homemade coconut chutney typically lacks preservatives that would inhibit microbial growth.
To extend the shelf life of your coconut chutney, temper mustard seeds and curry leaves in oil and add it to the chutney. The oil acts as a barrier against air, and the spices have some antimicrobial properties. Also, always use a clean, dry spoon when serving to avoid introducing additional contaminants.