The Science of Beer

With the Super Bowl just around the corner you can bet that beer sales will get a major boost. This year, I urge you take a moment and think about where beer comes from and how it’s made.

All beer includes four basic ingredients: water, malt, hops, and yeast. Beer is mostly water and for that reason, it is important to start with high quality water, but brewers have a variety of standards. Some breweries use filtered water - several Belgian microbreweries even use spring water! The Brooklyn Brewery in New York prides itself on using New York City tap water.

The first step in brewing involves bringing water to a boil and combining it with malt extract, which is a monosaccharide. Malts come in dozens of varieties and can impart a diverse set of flavors from almonds, to coffee, to chocolate.

Hops are also added into the wort (unfermented beer) during the boiling process. It turns out that hops are actually flowers and are in the same family as Cannabis sativa. Like malt, hops come in wide variety of flavors, but are used to add bitterness, which is measured using the alpha acid (AA) scale. Milder beers typically have an AA of 3-5% whereas stronger ales like India Pale Ale’s may use hops with AA ratings as high as 14%.

Many people are surprised to learn that yeast is actually fungus and for every style of beer, there is a variety of yeast that is perfectly adapted to it. Yeast is really the workhorse of beer as it converts the malt sugars into alcohol and carbon dioxide. But the yeast can also add flavor and complexity to beer. For example, when wheat beer is fermented at lower temperatures (60 degrees F) the yeast will impart a distinct clove flavor. But raise the fermentation temperature to 70 degrees, and the yeast adds a banana overtone.

So the next time you enjoy a cold one, remember all the science behind beer. Cheers!


Want to read more? 
Check out these posts from the New Voices archives: Draft Beer, Not People and St. Patrick's Day Special: Beer.