Malt aroma & flavor
Low. In darker versions, any of roasted malt, caramel, or chocolate aroma and flavor attributes should be present at low levels.
North American Origin Ale Styles
American-Style Sour Ale
Ale · Pale to black
What to expect
Malt character: Low. Hop character: None to high.
Reading guide · The complete guideline attributes below preserve the source’s qualifications.Color · SRM
May vary widely
May vary widely. No numeric color range is assigned.
Pale / strawBlack
Pale to black · Illustrative colors on the shared, uneven SRM scale.
Return to color discoveryAlcohol · ABV
May vary widely
No numeric range is specified.
Bitterness · IBU
May vary widely
No numeric range is specified.
Brewers Association 2026 · Printed guideline page 16 · PDF page 25. Color graphics are illustrative.
The guideline, in detail
Official style attributes, including what may be present and what should be absent.
Hop aroma & flavor
None to high
Perceived bitterness
None to high
Body & mouthfeel
Low to high
Clarity
Chill haze, bacteria, and yeast-induced haze is acceptable at any temperature.
Color
Pale to black
Fermentation characteristics
Moderate to intense, yet balanced, fruity esters are present. Diacetyl, DMS, and Brettanomyces should not be present. The evolution of natural acidity at medium-low to high levels develops a balanced complexity and is expressed as a refreshing, pleasant sourness, in harmony with other attributes. The acidity present is usually in the form of lactic, acetic, and other organic acids naturally developed with acidified malt in the mash or in kettle or post wort fermentation and is produced by various microorganisms including certain bacteria and yeasts. Acidic character can be a complex balance of several types of acid and attributes of age. Wood vessels may be used during the fermentation and aging process, but wood-derived flavors such as vanillin should not be present. There should be no residual flavors from liquids previously aged in a barrel such as bourbon or sherry.
Additional guideline notes & competition context
Beers exhibiting wood-derived characters or characters of liquids previously aged in wood are categorized as Wood-Aged Sour Beer. Fruited versions are categorized elsewhere. Competition organizers may create subcategories which reflect groups of entries based on color, hop varieties, microflora, spices, or other ingredients, etc. When using these guidelines as the basis for evaluating entries at competitions, brewers may be asked to provide supplemental information about entries in this category to allow for accurate evaluation of diverse entries. Such information might include the underlying beer style upon which the entry is based, or other information unique to the entry such as ingredients or processing which influence perceived sensory outcomes.
Technical specifications, including gravity
Original Gravity (°Plato) May vary widely • Apparent Extract/Final Gravity (°Plato) May vary widely • Alcohol by Weight (Volume) May vary widely • Hop Bitterness (IBU) May vary widely • Color SRM (EBC) May vary widely (May vary widely EBC)