Stouts should be black with flavours and aromas derived from the use of roasted malts. Session Stouts are up to and including 4.9% ABV, stronger than this they become Premium Stouts, for which there is no upper ABV limit. Distinguished from Porters by having less fruitiness, though it is accepted that there is crossover between the two styles.
There are multiple variations including
Dry Stouts - Without sweetness but with an astringency which may come from unmalted dark roasted Barley
Oyster Stouts - One of three variations - designed to accompany Oysters, with the addition of Oyster shells, with the addition of whole Oysters. The last two of which will impart a subtle saltiness with addition sweetness if whole Oysters are used.
Oatmeal Stouts - The addition of Oatmeal results in a slightly sweeter more full bodied creamy stout
Milk Stouts - The addition of Lactose creates a smooth sweet stout with a more rounded and creamy mouthfeel which could also be accompanied by custard (vanilla) like notes.
Porters - Often dark brown, the roast notes are balanced by hop and fruit flavours which are not present in stout. Fruit is usually dried fruit such as rasins and sultanas, can also have notes of coffee in the roastiness.
Colour
Dark Brown to Black
Clarity
Clear to Bright, though the darkness of the beer may make this difficult to see without the use of a torch
Carbonation
Low
Alcohol
Not detectable
Hop
Not present in stout but can be earthy, grassy or peppery in porters
Malt
Present throughout, even in porters
Esters
Some fruitiness may be detected in porters but not always
Phenols
None
Fermentation By-Products
None
Body
Light to medium
Carbonation
Low
Finish Length
Medium, but can be long and linegering in the more roasty examples
Attenuation
Dry stouts tend to have long dry finishes which can be moderate to strong but this isn't as obvious in sweeter examples or Porters which tend to be minimal to moderate
Hops
Usually traditional UK grown varieties, Bramling Cross or Fuggles can be used but to play supporting role to the Malt
Malt
A large malt bill is to be expected with the greater use of heavily roasted barley to create the dark colour - Chocolate Malt, Black Malt and Roasted Barley can all be used to great effect.
Water
Often 'Burtonised' by larger brewers but town water can be used
Yeast
Ale
