As written, this recipe is not extremely spicy but there is some spiciness in the background. The prepared horseradish can be a source of heat depending upon which brand you use. The greater potential comes from the blend of peppers in the Herb and Spice Blend. Cayenne is the hottest, followed by the white pepper. The black pepper also adds some spiciness but the dimension it adds is most important for creating a profile perfect for a dipping sauce. The blend of these three ground peppers provides a wide range of spiciness that you can control. Adjust the quantities of the horseradish and peppers until you get just the level of heat you desire.