Bottled horseradish will keep in the refrigerator 3 to 4 months after opening
Q. How long can bottled horseradish keep in the refrigerator? I need a teaspoon for a smoked salmon ball and I’ve had mine a long time. But it doesn’t have any visible mold, and it has a great fragrance.
A. The official date for commercially prepared, bottled horseradish is 3 to 4 months after opening. However, there’s a trick to know about horseradish. The bottled stuff loses potency pretty quickly after you open it. Take a taste from a freshly opened bottle and a bottle that’s been open for as little as a couple of weeks and you will probably be able to detect a big difference.
So you have a choice. If you want the nose-clearing punch and heat of horseradish, it’s worth buying another jar, especially if you’re making something that really depends on it, such a sauce to serve with roast beef. But if you just want a little heat and a hint of flavor for a recipe a bottle that has been open a while may be fine.