Aroma: The best examples have some malt aroma, often (but not always) with a caramel quality. Mild to moderate fruitiness. Hop aroma can range from moderate to none (UK varieties typically, although US varieties may be used). Generally no diacetyl, although very low levels are allowed.
Appearance: Medium gold to medium copper. Good to brilliant clarity. Low to moderate white to off-white head. May have very little head due to low carbonation.
Flavor: Medium to high bitterness. Most have moderately low to moderately high fruity esters. Moderate to low hop flavor (earthy, resiny, and/or floral UK varieties typically, although US varieties may be used). Low to medium maltiness with a dry finish. Caramel flavors are common but not required. Balance is often decidedly bitter, although the bitterness should not completely overpower the malt flavor, esters and hop flavor. Generally no diacetyl, although very low levels are allowed.
Mouthfeel: Medium-light to medium body. Carbonation low, although bottled and canned commercial examples can have moderate carbonation.
Impression: A flavorful, yet refreshing, session beer. Some examples can be more malt balanced, but this should not override the overall bitter impression. Drinkability is a critical component of the style; emphasis is still on the bittering hop addition as opposed to the aggressive middle and late hopping seen in American ales.
Comments: More evident malt flavor than in an ordinary bitter, this is a stronger, session-strength ale. Some modern variants are brewed exclusively with pale malt and are known as golden or summer bitters. Most bottled or kegged versions of UK-produced bitters are higher-alcohol versions of their cask (draught) products produced specifically for export. The IBU levels are often not adjusted, so the versions available in the US often do not directly correspond to their style subcategories in Britain. This style guideline reflects the "real ale" version of the style, not the export formulations of commercial products.
Ingredients: Pale ale, amber, and/or crystal malts, may use a touch of black malt for color adjustment. May use sugar adjuncts, corn or wheat. English hops most typical, although American and European varieties are becoming more common (particularly in the paler examples). Characterful English yeast. Often medium sulfate water is used.
Commercial Examples: Fuller's London Pride, Coniston Bluebird Bitter, Timothy Taylor Landlord, Adnams SSB, Young's Special, Shepherd Neame Masterbrew Bitter, Greene King Ruddles County Bitter, RCH Pitchfork Rebellious Bitter, Brains SA, Black Sheep Best Bitter, Goose Island Honkers Ale, Rogue Younger's Special Bitter