Irish Red Ale distinguishes itself from Scottish Bitters by using which ingredient?

Irish Red Ale is distinguished from Scottish Bitters primarily by the inclusion of flaked barley. This ingredient contributes to the characteristic mouthfeel and body of the beer, enhancing its smoothness and drinkability, which are signature traits of Irish Red Ales. Flaked barley helps in achieving a fuller, creamier texture without significantly affecting the flavor profile, allowing the subtle malt sweetness and caramel notes to shine through.

While barley malt is fundamental to both styles, both utilize it as a base. Wheat is not typically a defining ingredient in either style, thus not relevant to the distinction. Caramel malt may appear in both but is not a defining feature to distinguish Irish Red Ale from Scottish Bitters; it is the specific use of flaked barley that creates a noticeable differentiation. The use of flaked barley is crucial in providing that smooth, rich mouthfeel that sets Irish Red Ales apart from their Scottish counterparts.