The science of brewing

How the beer you love gets from grains in a field to beer in a glass

Mark Hendricks, Science & Technology Editor Ω

This board shows the process that the raw ingredients undergo to become beer once it's arrived at a brewery. Mark Hendricks/The Omega

This board shows the process that the raw ingredients undergo to become beer once it’s arrived at a brewery. Mark Hendricks/The Omega

The beers that so many people enjoy around the world undergo quite a remarkable process from field to glass. There are four key ingredients that go into making beer: barley (or other cereal grains), hops, water and yeast.

To get a detailed view into the process of making beer, I spoke with Chris Stewart, assistant brewer at The Noble Pig.

It all starts with barley in a field. The barley is harvested and sent to a malting facility. Malting is the process of soaking the harvested grain and then drying it with high heat to produce a partially germinated grain. The barley is then roasted to a desired level depending on the type of beer being produced, a light roast for lagers, a heavier roast for porters.

The grains are then coarsely ground and mixed with hot water at a brewery in a process called mashing. Mashing breaks down the starches present in the grains and converts them into simple sugars that will be used later in the brewing process.

The liquid (which is now a mixture of simple sugars, water, and barley juice) is extracted from the leftover mash. This liquid is known as the wort.

These hops, grown on the patio of The Noble Pig Brewhouse, will be added to beer to produce flavour and bitterness. Mark Hendricks/The Omega

These hops, grown on the patio of The Noble Pig Brewhouse, will be added to beer to produce flavour and bitterness. Mark Hendricks/The Omega

The wort is boiled and hops are added to the mixture. Hops give beer its bitterness and some of the flavour, the rest being determined by the types of cereal grains used and the temperature of the liquid. Once the boiling process is completed, a whirlpool is induced to separate the chunky hops and other congealed proteins from the liquid. The process is almost done but we still don’t have beer.

The wort is cooled and moved into a fermenter where the yeast is added. The addition of yeast officially changes the wort into beer! This is where those simple sugars produced earlier come into play. The yeast eats the simple sugars and converts it into alcohol and carbon dioxide.

The beer is then cooled in the fermenter, causing the carbon dioxide to bond to the beer (this is carbonation) and is left to age for at least a month depending on the type of beer being made. At this point it is ready to be pumped through the pipes of your local brewery and poured into a glass for your enjoyment!