When putting different beers into different categories there are many different measures that one can use. The most obvious ones are the beers colour and its alcoholic content. However, there are other criteria that people use to distinguish between certain beers. The most obvious criterion is of course the alcoholic content of the beer and is measured by the amount of alcohol present. It is usually written on the sides of bottles or on the side of the serving taps for draught beers and is expressed as a percentage number.
This is the ratio of alcohol to the volume of the beer. A low strength beer is likely to read around 3.2 % while a stronger beer will be over 4%. Although the rise may seem minimal there are many that will testify that a small percentage change can have a rather marked difference on the consumer at the end of the evening. The alcoholic content percentage of the beer will be determined by how much sugar the brewer decides to add. During the fermentation process the yeast eats the sugar and turns it into alcohol so more sugar added makes the beer stronger. Some brewers even add different types of sugar to change the alcoholic content and the taste. You do not need to taste a beer to spot differences between them. The colour of a beer can change markedly, and this is affected by the type of malts that have been added to them. Stouts are black, and this is as a result of using roasted malted barley in a similar way to how coffee beans are prepared. The highly heated sugars, amino acids and grains to form the dark colour.
The more intense the heating the darker the beer is likely to become. Lagers and American beers are yellow and almost see through in colour. This is as a result of them being brewed at much lower temperatures and with yeast that tends to sit at the bottom of the mix during fermentation. British Bitters are somewhat in between these two extremes with the heating process being hot but not as extreme as the stout process. The use of yeast that rises to the top during the fermentation process allows for chemicals known as esters to be formed which gives the Ales their robust colours. The way a beer is colour coded is by the standard reference method.
The actual taste of the beer will separate major beers from each other. The most defined difference is between a beer and a lager. The first thing before the taste buds are even activated is that the lager is likely to be fizzier than the beer. Using a completely different type yeast during fermentation the lager is likely to have a cleaner, smoother and crisper taste. The lager yeast can survive in much cooler temperatures than the bitter yeast and lies at the bottom.
Bitters and Ales have a fruitier flavour and aroma, as their yeast is more mixed in during the fermentation process. Also, the fermentation process is faster than with the lagers, so the flavours have not had time to have been filtered away. There are a number of ways to differentiate between separate beers and basically it will be the individual who will pick on one particular aspect to suit their own particular taste. There are hundreds of different beers and lagers today and all of them have their own unique selling point.