For a classic cocktail dipping sauce, add 2 tablespoons horseradish powder to 1 cup ketchup. For a thick, sharp horseradish sauce, mix 1 part horseradish powder with 3 parts water. For more of a sauce, thin out with yogurt, lemon juice or vinegar. Since heat destroys the volatile oils that give horseradish its distinctive bite, we recommend you add horseradish powder after cooking. Ingredients: Horseradish.