Wort is a brewing term that means, essentially, unfermented beer. It is beer before it is the beer that we drink and it is important for homebrewers to understand what wort is and how it factors into the beer making process.
What is Wort?
Many things must happen in the beer making process before we even get to the fermentation stage, which is when beer actually becomes beer. It all begins with making the wort, which will give the beer its fundamental flavors, including those of the grains and hops that the brewer's recipe calls for.
Think of wort as a 'beer starter.' It is the sweet, malty liquid that begins by converting starches in malted grains into sugar (the process of mashing). Hot water is added to the mash to allow the enzymes to finish the conversion from starch to sugar. This is the wort.
The Make Up of the Wort
This mixture then goes through a process called lautering. During this stage, the grain husks and other solids are separated from the liquid wort.
Note: Homebrewers will often skip the mashing and lautering stages by starting out with a liquid malt extract.
The resulting wort - that now clean, sugary liquid that can be as much as 90% water - is now ready for brewing. The color of the wort is usually the same as the final product.
At this stage, the carbohydrate and basic sugar content can look something like this:
- 12% monosaccharides,
- 5% sucrose,
- 47% maltose,
- 15%maltotriose, and
- 25% higher saccharides (e.g. dextrin) (Kapral, Oxford Companion to Beer)
This is a general guide and will vary based on the grains used in the mash.
Each grain will add different characteristics to the flavor of the finished beer. For instance, using rye in a rye IPA will give it a spicier flavor while oats used for oatmeal stouts will produce a smooth, somewhat creamier taste.
Boiling the Wort and Adding Hops
Wort remains unstable until it is boiled, which sterilizes the liquid and halts the starch to sugar conversion.
Hops are added to the liquid wort during boiling and they serve a few functions, primarily to add the final flavors to the working beer. They are often added to the wort in three stages while boiling.
- Bittering hops are added first to balance the sweetness of the sugary wort and are typically given an hour in the boil.
- Hops that are more floral, earthy, and/or citrusy in character are added right around 15 minutes before the end of the boil to add their desired flavors to the wort. These might be considered 'flavoring' hops.
- Finally, the finishing hops are added at the end of the boil or right after it is done. The focus of these hops is to add aroma to the wort.
After boiling, this now-flavored wort is cooled. It is ready for the yeast to be added and for the process of fermentation to begin.