L

Lager: A classification of beer styles made with a bottom fermenting yeast, lagers generally are smooth, elegant, crisp, and clean.
Lagering: The period during which lager beer is aged.
Lager Yeast: Also known as bottom-fermenting yeast, this teasy does best at temperatures between 33-50 degrees F. Has a tendency not to flocculate or form a head of yeast on the surface of the brew.
Lambic: Wheat beer originally produced in the Bruxelloise region of Belgium with a strong acidic character from the spontaneous fermentation from wild yeast.
Lautering: The separation of solids (the mash) from the liquid malt extract called wort.
Lauter Tun: A large vessel with a perforated false bottom. It is used to strain the sweet wort off the spent grains after mashing.
Lead: An ion that causes haze and is toxic.
Light Ale: In England, an alternative term for bottled bitter. In Scotland, a dark ale of low gravity.
Liquefication: See dextrinization.
Liquor: A brewers term for water used in brewing.
Lovibond: A scale on which malt, wort, and beer color are usually measured.
Lupulin Glands: The tiny yellow sacs found at the base of the petals of the hop cone. They contain the alpha acids, beta acids, and hop oils.
Lupulone: See beta-acid.