McDonald’s Canada continues to reveal the secret behind its foods. Last month, the fast food giant explained why their advertised products were different from the products actually sold in store. McDonald’s continued with this PR campaign of full disclosure and revealed the secret to what is in its famous Big Mac sauce. Executive Chef Dan Coudreaut remade the Big Mac in the McDonald’s test kitchen with just everyday grocery items, such as mayonnaise, sweet pickle relish, yellow mustard, white wine vinegar, garlic powder, onion powder, and paprika. Chef Coudreaut explained that the special sauce is “just like something you would make at home.” Serious Eats double-checked this statement: as found on a list of Big Mac sauce ingredients found on the McDonald’s Canada website, the homemade version is closely similar, with four exceptions: xanthan gum (a food thickening agent), potassium sorbate (a food preservative), and calcium disodium EDTA (another preservative).