The Science of Beer

Beer is made from four basic ingredients: a grain (usually barley but sometimes wheat or rye), water, hops, and yeast. The basic idea is to extract the sugars from the grains so that the yeast can become alcohol and carbon dioxide, leading to beer.

First, the grains are harvested and processed by heating, drying out and cracking – a step called malting. The main goal of malting is to isolate the enzymes needed for brewing. An enzyme is a protein molecule in cells that works as a catalyst to speed up chemical reactions.

Next, the grains go through a process known as mashing. The processed grains are steeped in hot water for about an hour (similar to making tea… but it’s beer tea). This activates the enzymes in the grains, causing them to break down and release sugars. Once this is all done, the water is drained from the mash, which is now full of sugar from the grains. This sticky, sweet liquid is called wort. It’s basically unmade beer, sort of like how dough is unmade bread.

The wort is boiled for about an hour while hops and other spices are added several times to create different brews. Hops are a vine plant’s small, green cone-like fruits. They provide bitterness to balance out all the sugar in the wort. They also provide flavor and act as a natural preservative, which is what they were first used for.

The cooled, strained and filtered wort is then put into a fermenting vessel to which yeast is added. At this point, the brewing is complete and fermentation begins. During this time, the beer is stored for a couple of weeks at room temperature (in the case of ales) or several weeks at cold temperatures (in the case of lagers), while the yeast eats up all the sugar in the wort and spits out carbon dioxide and alcohol waste products. Yum!

At this point, alcoholic beer is born. However, it’s still in a flat and uncarbonated state. This flat beer is bottled and can either be artificially carbonated like a soda, or if it’s going to be ‘bottle conditioned’, allowed to naturally carbonate via the carbon dioxide the yeast produces.


After allowing the beer to age for anywhere from a few weeks to a few months, you can drink the beer – and it’s delicious!