Why did I get a low starch to sugar conversion? Kim June 22, 2020 12:44 Updated This could be due to a few factors; Incorrect grain crush Diastatic properties of the grain bill Incorrect mash temperature Wrong mash time Incorrect mash water pH Incorrect mash water calculations Mash thickness Related articles What is BU/GU? Is the 'batch volume' the final, end amount I'll finish up with? How can I improve my efficiency? Calculation - Mash and Sparge Water Volume How is efficiency defined on the calculator?