Refractometer: A tool that measures the density of a solution. It's used to take readings in during brewing. A refractometer used for brewing, features a Brix scale which measures sugar content in the wort.
Degrees Brix: is the sugar content of an aqueous solution. One degree Brix is 1 gram of sucrose in 100 grams of solution and represents the strength of the solution as percentage by weight (% w/w).
Vorlauf: Is the process of clarifying the wort from the mash tun. Slowly move the wort into a container and then pouring softly back onto the top of the mash trying not to disturb the grain bed. The propose is to establish the grain bed as a filter for the wort being drawn off. The grain husks will then act as filter and enhance clarity.When the wort runs mostly clear, the vorlauf process is complete and sparging may begin.
OG: Original Gravity
FG: Final Gravity
OG and FG are both used in the ABV calculation
ABV: Alcohol by Volume
How much alcohol is in your beer.
(OG - FG) x 131.25 = ABV%
Used in secondary fermentation when monitoring density in pertaining to ABV calculation
hydrometer: An instrument for measuring the density of liquids.
It allows you to take readings for: OG, FG, SG, by buoyancy. You'll record your measurements at various intervals of the beer making process to use in the calculation for your ABV.
CO2: Carbon Dioxide
A bi-product of yeast. Yeast eat sugars in your brew and create alcohol and "Bubbles."
DME: Dried Malt Extract
Dried "extract" (like flour) is processed grains to make your wort and/or to add to your boil/brew.
LME: Liquid Malt Extract
Wet "extract" (like molasses) is processed grains to make your wort and/or to add to your boil/brew.
IBU: International Bittering Units (Tinseth)
How hoppy your beer is.
Rack: To siphon or transfer beer from one container to another.
Dry Hopping: Adding hops to the wort after the boil. Dry hopping increases the hops character of the aroma and flavor of the final beer without increasing the bitterness or IBUs.
BJCP: Beer Judge Certification Program