Yes, mustard can be left out, but refrigeration is recommended for optimal flavor retention.
While refrigeration isn't strictly necessary to prevent spoilage, it will help maintain the mustard's flavor and quality over a longer period. Major brands like French's state that their mustard has a shelf life of 18 months in a squeeze bottle and 24 months in a glass jar from the date of manufacture, even without refrigeration. However, storing it in the refrigerator will help preserve that sharp, tangy taste for as long as possible.
Consider the following:
- Flavor: Unrefrigerated mustard may experience a gradual decline in flavor intensity.
- Safety: Mustard's acidity helps inhibit bacterial growth, making it relatively safe at room temperature.
- Shelf Life: Refrigeration generally extends the palatable shelf life.
In summary, leaving mustard out won't necessarily make it unsafe, but for the best flavor experience, refrigerate it after opening.
