The HBRC is a complete beer recipe calculator. With it you can quickly determine the recipe gravity from different malts and extracts, and the bitterness contributions from different hop additions, for any batch size between 5 and 12 gallons.
Side One offers two functions: a Gravity-Volume Converter, and a Gravity Contribution Calculator. The gravity-volume converter is useful for figuring the change in your wort gravity between the initial boil volume and your final recipe volume (OG). Simply line up the scales for the initial volume and gravity readings (Slide A), and read off the corresponding gravity at any other volume.
The Gravity Contribution Calculator works similarly. Simply line up Weight scale to the Yield of a particular ingredient, and read its gravity contribution on the scale below as a function of wort volume. For instance: One half pound of Steeped Crystal Malt yields a gravity of 1.003 at 3 gallons, 1.0045 at 2 gallons, and 1.006 at 1.5 gallons according to the scale.
