IBU – International Bitterness Unit, provides a measure of the bitterness of beer, which is given to the beer by the hops used during the brewing process.
krausening – adding newly fermenting beer to older beer. From krausen, the thick foamy head on fermenting beer.
Reinheitsgebot – Bavarian beer purity and taxation law enacted in 1516. Only water, malt and hops were allowed as ingredients. Malt and hops were both taxed as opposed to other possible ingredients.
Wort – is the liquid that comes out of the mash tun when you make beer. It’s not beer yet since it hasn’t fermented, but it has the sugars from the barley and a unique flavor.