What efficiencies can I expect from the G30/ G30³ ? This depends a lot on your grain bill, grain crush and recipe. In general we can say that our brewers experience efficiencies of up to 85% when using the G30. Related articles How can I improve my efficiency? What is the boil off rate on the G30 / G30³ What are the minimum and maximum grain bills for the G30? What is the difference between Brewhouse Efficiency and Mash Efficiency? What is a simple way of reducing power to the element on the G30 to lower the temperature?