This morning I brewed a Kolsch all grain. I had previously crushed the grain myself, using a new Corona grain mill. I thought I cruahed the grain too fine and that I'd have trouble but everything went fine. No cloged mash tuns and my strike temp was perfect. No apparent problem with the sparge. I measured the volume of the wort and SG in the kettle both before the boil and after the boil and after the wort had cooled. According to Promash the SG should be 1.044 to 1.050. Fine, mine was 1.042. Now the problem, when I plug the 1.042 into the Promash efficiency determinator, check the box for sample taken from kettle and fill in the volume amount, Promash tells me that I have 50% efficiency that ideally I should get a 1.062 SG. If that's true why do they originally say that the SG should be 1.044 to 1.050 Also is there any explanation why I got such a lousy efficiency. 50% really stinks. This beer will probably taste like pond water or worse yet like Bud Light