Scottish heavy ale is moderate in strength and dominated by a smooth, sweet maltiness balanced with low, but perceptible hop bitterness. Hop flavor or aroma should not be perceived. Scottish heavy ale will have a medium degree of malty caramellike, soft and chewy character in flavor and mouthfeel. It has medium body, and fruity esters are very low, if evident Yeast characters such as diacetyl (butterscotch) and sulfuriness are acceptable at very low levels. The color will range from golden amber to deep brown. Bottled versions of this traditional draft beer may contain higher amounts of carbon dioxide than is typical for mildly carbonated draft versions. Chill haze is acceptable at low temperatures.
Though there is little evidence suggesting that traditionally made Scottish-style heavy ales exhibited peat smoke character, the current marketplace offers many Scottish-style heavy ales with peat or smoke character present at low to medium levels . Thus a peaty/smoky character may be evident at low levels (ales with medium or higher smoke character would be considered a smoke flavored beer and considered in another category).
Scottish-style heavy ales may be split into two subcategories: Traditional (no smoke character) and Peated (low level of peat smoke character)