Buttermilk, Kefir, Sour Cream, and Other Fermented or Acidified Milk and Cream

Butterfat content is the primary classification axis within this heading: sour cream lines are subdivided at the 10-digit level by whether butterfat is not over 45% or over 45%, and dried sour cream is further split at the 6% and 35% butterfat thresholds under US Note 8. Fluid buttermilk (0403902000) and fermented milk other than dried (0403908500) occupy separate lines. Colombia leads US import supply for this heading, with India and Canada also significant sources — a supplier mix that spans both kefir-style cultured products and traditional sour cream. USDA FSIS governs admissibility; importers should confirm establishment approval and butterfat specifications before classification.