Barfield
Honey, put on that party dress
On page 12 of Greg's book, there's a familiar and frequently requoted formula for as-is, coarse grind yield. The formula is also reposted by Stan Hieronymus at ProBrewer here.
What am I missing?
My question is: what is the magic number "0.002"? It's not discussed in the text. Assuming a typical malt from Crisp, for example, with a dry basis, coarse grind extract potential of 80.8% and a 4% moisture content, as-is coarse grind potential (including the 0.002 magic number) is 0.808/(1+0.04) - 0.002, or 0.7749 etc. If the magic number were left out, the AICG yield is 0.808/(1+1.04) = 0.7769 etc. The percentage difference between these two values is (0.7749 - 0.7769)/0.7769 = -0.0026, or -0.25 percent. That's a terribly small difference, particularly given the uncertanties elsewhere in the equation (i.e., moisture content and DBCG measurement).DBCG/(1 + moisture content) - .002 = AICG (as-is coarse grind)
What am I missing?