Back To Basics: Barley

Barley is one of the earliest cultivated cereal grains, but very little of it is directly used for human consumption anymore. Now it is primarily used as livestock feed, and as an ingredient in alcohol. Barley, in its harvested form, isn't usable in making beer, and that is why the malting, kilning and mashing processes are needed.

Barley seed during the malting process

Through using heat and moisture the malting process tricks the barley into starting the germination process. This process releases newly created and preexisting enzymes from the aleurone layer.

These enzymes begin to break down the insoluble starches, proteins and carbohydrates within the endosperm into smaller carbohydrates, amino acids, lipids, and soluble starch. The whole reason that these transformations are taking place is to give the acrospire energy to grow, and eventually become an adult plant. 

We don't want this process to waste energy growing the acrospire any longer than necessary when it could be saved to be turned into alcohol instead. That is why the process is stopped by kilning the barley when the proper balance between resource conversion and acrospire growth is reached. 

The process of kilning drys and roasts the barley. The temperature that the barley is kilned at determines the characteristics of the finished product. Base grains and specialty grains are the two classifications of kilned barley, and they have very different functions in the brewing process.

With a lower kilning temperature, base grains have retained a majority of their enzymes, and have a lighter roast. These grains will be the source of the majority of the fermentable sugars that will be present in the wort, but they don't contain these sugars until they go through the mashing process. The mashing process creates these sugars by soaking the barley in hot water with the correct conditions for the enzymes to break starches down into fermentable sugars. The liquid that results from the mashing process can then be dehydrated to create malt extract.

Specialty grains don't need to go through this mashing process, because they have been roasted in a way that no further sugars could be extracted from their starch reserves. Instead of adding fermentable sugars their function is to add flavor, color and body to beer. These grains only need to be steeped to impart their characteristics on a beer.

Barley is one of the basic building blocks of beer. Using barley that has gone through the malting, mashing and kilning processes can produce a wide array of complex color and flavor profiles in your beer, but most importantly it will provide yeast with fermentable sugars to be turned into alcohol.