Question

Why the butter developed bad taste and smell when left outside for a long time

Answer 1

Related pages: Taste  ·  Off-flavors  ·  Grades  · 

Butter varies in flavor, both good and bad. Flavors can be: absorbed, bacterial, or chemical. Left in the open air, butter turns rancid quickly. This is why a butter crock (which keeps the butter away from air) is valuable. Due to its high water content, the size of the water droplets in the water-in-oil emulsion being less than 6 µm, butter is subject to rapid microbiological spoilage at normal temperatures.



It used to be that one farmer’s butter tastes different from another’s because of the pasture. You could taste the pasture. Most dry feeds (like hay or concentrates), silage, green alfalfa, and various grasses produce feed flavors in butter. Butter would taste different if the cow was eating feed (alfalfa, sweet clover) or weeds (onion grass, dandelions). Today, most cows eat pretty standardized diets, but the smell of the barn will affect flavors, as does the amount of time since the cows last ate. Cows impart an odor and taste within 30 minutes of eating or breathing grass or corn silage, legume hay, or brewer's grains. Similarly, butter will readily absorb flavors and odors from your refrigerator.