Gluten Info We put no wheat gluten directly into Gravy Master. The hydrolyzed vegetable protein used in Gravy Master is corn and soy based, not wheat. It is wheat gluten that most sensitive people react to. Our supplier has informed us that while it is possible that not all the corn gluten has been completely hydrolyzed, the trace amounts that might remain should not affect most gluten sensitivities. The vinegar used in Gravy Master is apple cider vinegar. The caramelized sugar is derived from pure cane sugar, the caramel color is derived from corn syrup. Gravy Master is certified Kosher by the Orthodox Union.