Potions of fire breath were made of orange-flickering liquid that gave off smoke, made from ash infused with the magic of fire-breathing Dragons. When consumed, the potion warmed like a fine whiskey, but quickly grew to the point of discomfortability. This discomfort caused a need to belch burbles within the user's stomach, which would fly forward in the form of an Evocation of fire.
Both the heat level and quantity of the released flames paled in comparison to a true Potion of Dragon's Breath, but potions of fire breath were more commonly accessible as they did not require draconic parts to synthesize.