An ester is a flavour resulting from the fermentation process. Some yeast produce fruity esters while others can be spicy, flowery, etc.
IBU stands for International Bitterness Unit and is a means for measuring the hop infused bitterness on a finished beer.
Lagering comes from the German language for storage and refers to allowing the beer to ferment, settle and mature over the course of several weeks or months. This is usually done at low temperatures which allow the yeast and various byproducts to drop out leaving behind a clear product.
Pitching is the act of adding yeast to wort. It is often considered the first time the liquid has ‘officially’ become beer.
Sparging is the act of running hot water through the grain at the end of the mash process in order ‘wash’ the sugars away from the grain. This is usually done in order to collect the wort in the kettle.
An adjunct is a fermentable ingredient, usually not grain, that can impart different flavours or result in a lighter tasting final beer.
Body refers to the ‘feel’ of the beer in your mouth. Sometimes this is referred to as how ‘thick’ or ‘thin’ tasting the beer is.
A micro-organism that is used in the brewing process to convert fermentable sugars into (among other things) alcohol.
Trub is the name for the material, along with hop debris, left after the wort has been boiled then transferred and cooled. Although it contains yeast nutrients, its presence can impart off-flavors in the finished beer.
Dry hopping is the process of adding hops late in the process, usually in the primary fermenter after fermentation has completed or into a secondary fermenter. It is meant to add extra hop aroma without imparting too much bitterness to the final beer.