How to tell ale from lager?

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Fundamentally, beer can be categorised as lager or ale. India, a largely lager drinking country, has had limited exposure to ales. But in major beer drinking nations, ales occupy a place of pride. Civilizations as far back as the Sumerians and Egyptians have been brewing and drinking what would be considered ales. Lagers, on the other hand, may have only been around since the mid-nineteenth century.

The main difference between ales and lagers is the type of yeast used in the brewing process. Ales are fermented warm and made with a top-fermenting yeast, which is a yeast that rises to the top of the brew during fermentation. Ales are stronger and more forceful in taste than lagers because of their relatively fast and warm fermentation. Many countries, including England, serve their ales at room temperature. That perhaps has spread the notion that the British drink warm beer. That is only a half-truth because while they do enjoy warm ales, they don’t have their lager at room temperature. Lagers, from the German word “lagern” meaning to store, are made with a bottom or cold-fermenting yeast that sinks to the bottom of the brew during the fermentation process.
Ales brew quickly and in some cases can be brewed in as little as seven days. Lagers on the other hand need to age before their brewing process is complete. This can increase their brewing time to more than a month or more. This longer, colder fermentation process inhibits the production of esters (which give beer a more fruity taste) and avoids other fermentation byproducts which are usually seen in ales. The lager process creates beers with a generally cleaner, smoother, crisper, and more mellow taste. Unlike ales, lagers should always be served cold.