Hineka

Hineka manifests as stale, papery, or honey-like notes that mask the fresh fruit and floral character of sake. The primary cause is DMTS, which forms when methionine from rice protein degrades under poor storage conditions. UV light, even brief exposure to sunlight or fluorescent lighting, accelerates hineka development. This is why sake bottles are typically brown, green, or wrapped in paper. While hineka is almost always undesirable in fresh sake, some intentionally aged koshu (old sake) may develop complex, sherry-like oxidation notes that are considered a feature rather than a defect.