Buttermilk
Buttermilk is a dairy drink made by adding lactic acid bacteria to milk to produce a fermented dairy drink. Traditionally, it was made from the nearly fat-free milk remaining after churning butter from cream, which was cultured with natural bacteria prior to and during churning, giving a slight sour taste to the buttermilk and preventing spoilage. However, with the ubiquity of refrigeration in industrialized countries, butter in those areas is typically made from uncultured or "sweet" cream. Therefore, most modern buttermilk is specifically produced by inoculating fresh, pasteurized milk, and is available in different levels of fat content.
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