What efficiencies can I expect from the G70? Nat September 20, 2021 12:02 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 that can be brewed with on the G70? G70 Manual Operation Features Post Brew Day App Notifications What do I clean the Grainfather G30 or G70 with?