Beer is the world's most widely consumedalcoholic beverage; it is the third most popular drink overall, after water and tea. It is thought by some to be the oldest fermented beverage. Beer is produced by the saccharification of starch and fermentation of the resulting sugar.

The starch and saccharification enzymes are often derived from malted cereal grains, most commonly malted barley and malted wheat. Unmalted maize (US: corn) and rice are widely used adjuncts to lighten the flavor and because of their lower cost. The preparation of beer is called brewing. Most beer is flavoured with hops, which add bitterness and act as a natural preservative, though other flavourings such as herbs or fruit may occasionally be included. Some of humanity's earliest known writings refer to the production and distribution of beer: the Code of Hammurabi included laws regulating beer and beer parlours, and "The Hymn to Ninkasi", a prayer to the Mesopotamian goddess of beer, served as both a prayer and as a method of remembering the recipe for beer in a culture with few literate people. Today, the brewing industry is a global business, consisting of several dominant multinational companies and many thousands of smaller producers ranging from brewpubs to regional breweries.

The strength of beer is usually around 4% to 6% alcohol by volume (abv) though may range from less than 1% abv, to over 20% abv in rare cases.

Beer forms part of the culture of beer-drinking nations and is associated with social traditions such as beer festivals, as well as a rich pub culture involving activities like pub crawling and pub games such as bar billiards.
Beer is made from four basic ingredients: Barley, water, hops and yeast. The basic idea is to extract the sugars from grains (usually barley) so that the yeast can eat it up and spit out alcohol and CO2 thus making beer.

The brewing process starts with grains, usually barley (although sometimes wheat, rye or other such things.) The grain is harvested and processed. This is done by heating, drying out and cracking the grain. The main goal of malting the grains to isolate the enzymes wanted by brewers so that it’s ready for mashing.
The grains then go through a process know as mashing, in which they are steeped in hot, but not boiling, water for about an hour, sort of like you were making tea. This activates enzymes in the grains which causes it to begin to break down and release the sugar inside of it. Once this is accomplished you drain the hot water from the mash that’s full of the sugar from the grains. You’ve now got a hot, sticky sweet liquid called wort which is basically unmade beer, sort of like dough is unmade bread.

The wort is boiled for about an hour during which time hops are added at various points.

What are hops? Hops are the small, green cone-like fruit of a vine plant. They provide bitterness to balance out all the sugar in the wort and provide flavor. They also act as a natural preservative, which is what they were first used for.
Once the hour long boil is up the wort is cooled, strained and filtered. It’s then put in a sealed container and yeast is added to it. The brewing is now complete and fermentation begins. The beer is then stored for a couple of weeks at room temperature (in the case of ales) or many many weeks at cold temperatures (in the case of lagers) while the yeast works its fermentation magic. Basically the yeast eats up all that sugar from the grains that’s in the wort and spits out CO2 and alcohol as waste products.

You’ve now got alcoholic beer, however it is still flat and uncarbonated. The flat beer is bottled, at which time it is either artificially carbonated like a soda, or if it’s going to be ‘bottle conditioned’ it’s allowed to naturally carbonate via the CO2 the yeast produces. After allowing it to age for anywhere from a few weeks to a few months you drink the beer, and it’s delicious!