Ask Mr. Wizard

OG is lower than target


John “Mick” Barnes • Marcellus, New York asks,

Help! I have been brewing for about 10 years and have just taken the step to all-grain. I have been reading and trying many of the recipes in BYO, and as long as I stay with extracts or partial mash, I am very close to the OGs. But when I do an all-grain batch, I am about ten points below the target OG. I know I can correct this with some DME, but I don’t want to. When you publish recipes, is it assumed that the brewer knows enough to adjust for mash efficiency, or are they already adjusted to some unknown mash efficiency? I run into the same problem with other books and publications.


The recipes published in Brew Your Own and in other magazines and books are indeed formulated with some efficiency in mind. In the case of regular columns, such as “Replicator,” the columnist
Response by Ashton Lewis.