An acidic liquid, such as wine or vinegar, produces a longer-lasting paste.[25] However, even then prepared mustard loses its pungency over time; the loss can be slowed by keeping a sealed container (opaque, or in the dark) in a cool place, or refrigerator.[26] Mustard can last indefinitely without becoming inedible or harmful, though it may dry out, lose flavor, or brown from oxidation.[24] Mixin