Believe it or not, even with all the different flavors and styles, the core ingredients in almost all beers are the same four simple, common ingredients. Some beers may have additional ingredients, and there are countless ways to prepare and cook these ingredients, but really all your need to make beer are grains, water, hops, and yeast. In fact in the Reinheitsgebot only allowed for water, barely, and hops – yeast was not yet known as an ingredient at that time. Today, you can find beers with a wide variety of fruits, grains, spices, and herbs. Different ingredients and combinations will give a beer certain characteristics, this is most obvious in seasonal beers that are often smooth and light in the summer compared to winter ales which may have more spice and bitterness.

What follows is a brief introduction to the ingredients of beer written with beer drinkers in mind. If you are interested in home-brewing and ingredient combinations, please check out the Beer Newb's articles on home-brewing.

Grains

When grains are roasted or otherwise cooked and fermented natural sugars are released (which, if you remember from your high school chemistry course, is the primary reason that beer has calories). However, which grains the brewer uses and how they are cooked and prepared has a great impact on the character, color and taste of the styles and individual brews you love.

The most common grain used in beer in barley, but you have no doubt also heard for white beers and oat/oatmeal stouts. A grain you may not have guessed you could turn into beer is corn (yes, corn otherwise known as maize is a grain). While today we are seeing an increase in internationalization of domestic brews, traditionally brews for different regions and countries are typified by the local ingredients. In addition to cooking methods, soil and weather also can affect the flavor of the grain and other ingredients.

Water

A large percentage of what you find in your glass is actually good ol' H20, making the choice of water a crucial component in the beer's flavor. The flavor and character of water itself is determined by the minerals and other micro-goodies floating around in there. Two of the most important minerals in affecting the final outcome of beer are magnesium and calcium. Along with other ingredients, all sorts of chemical reactions occur which may make a beer more bitter or smooth. While it is obviously possible today to use all sorts of modern science to get the exact mineral mix, the older and most established beers owe much to their natural local water supplies.

Hops

Hops have been known since ancient times when they were primarily used for the herbal-medicinal purposes. Before hops were used in the production of beer other herbs, spices, and plants were used for flavoring including heather, marigolds, and dandelion flowers. Today, hops are the most commonly used herb. Generally, the hops contribution to beer in enhanced bitterness in the taste or aroma of the beer. Like grains, the various varieties of hops have very different characteristics depending on where they are grown, and modern breweries may combine hops from all around the world to produce the desired flavors and aromas in their beers. To learn more about hops and their role in beer, check out this awesome feature article from Wikipedia.

In addition to hops, many other additives such as fruit as well as other herbs and spices can help develop the character of your beer. Common herbs and spices you will find in beers include ginsing, orange, saffron, juniper, and/or coriander. With the increasing microbrew and home-brewing culture, you may find these and maybe even more exotic extracts, herbs, and spices bringing you new flavors to enjoy.

Yeast

Finally, the last essential ingredient in beer is yeast. Relatively unknown as a vital part of the brewing process until relatively more recent times, ancient brewer's relied upon natural yeast to start the fermentation process. Beer was probably discovered by accident, when stored grain became wet and then interacted with naturally occurring yeast, resulting in the grain-keeper discovering a thirst quenching surprise. Even into the Middle Ages, brewers believed that there must be some magical or heavenly component for the production of beer. Even today, natural or wild yeast is still a crucial component of some brewing processes, especially Belgium lambics, though in most brewers they go and get all sciencey about the whole thing. It is common however to reuse yeasts from batch to batch. The yeasts serve to digest the sugars contributed the grains and other ingredients.

While there are many specific varieties of yeast, they can usually be separated into either the top or bottom-fermenting categories. Top-fermenting beers activate at fairly warm temperatures is most commonly associated with ales while bottom-fermenting yeasts are typical of lager style beers and activate at cooler temperatures.

Now that you know what goes into a beer, we encourage you to continue your beer education by learning how all the ingredients come together and the various techniques and equipment used in the brewing process. Checkout the Beer 101 Section for more information.