What efficiencies can I expect from the G70? Nat October 23, 2020 16:02 Updated This depends a lot on your grain bill, grain crush and recipe. Our overall testing has yielded efficiencies between of 70-85%. Related articles Instructions - G70 All Grain Brewing System What are the minimum and maximum grain bills I can brew with on the G70? G70 Manual Operation Features Post Brew Day App Notifications What is BU/GU?