Max & Min Grain Bill
The G70 system is designed for brewing larger batches. The 70L maximum preboil volume and 17kg maximum grain bill allows you to make enough wort or beer of any style as a pilot test batch or to share with your friends/ homebrew club.
With the standard pipework, a minimum batch size volume of 40L and a 8kg grain bill is required to ensure the overflow pipework is engaged during mashing which allows for the most accurate and stable mash temperature management.
With the micro pipework, a minimum batch size of 30L and 5.5kg grain bill is required for optimum function. For batches smaller than these our G30 Brewing System is optimised for batches up to 28L.
Setting up delayed heating
By holding down the heat button on the controller, the delayed heating function can be activated. You can also set up delayed heating on the G70 through the Grainfather Community App when you directly connect your device to the G70 wirelessly. You can also set your brew session in the planning stage to start at a particular time which will automatically set up delayed heating with your G70.
The Large Counterflow chiller
Water conservation is a serious concern for us at Grainfather and this is one of the primary reasons, counterflow chillers come standard with our brewing systems. To further our efforts in conservation we elected to use copper rather than stainless steel. This is because copper can have up to 20 times greater thermal conductivity than stainless steel, allowing our counter flow chiller to use less water over shorter transfer times. Copper has a long history in brewing and is relatively inert in wort and beer.
cross section of the g70 base
The heating element spans 80% of the base for optimal, even heating and the conical shaped floor allows for maximum yield of wort.
expected mash efficiencies
Depending upon your grain crush, we typically see mash efficiencies of between 72-82%. The efficiency on the equipment profile is pre-set to 80%, however, as expected with any brewing system if you are brewing at the upper limit of the grain bill you can expect the mash efficiency to drop a couple of points. At the minimum ranges of the grain bill a slight increase in mash efficiency can be observed due to the increased surface area exposure of the grains in the grain basket.
Boil off and losses
The boil off rate for the G70 is 3.5L per hour. The loss from the G70 unit is 3L and a further 2L loss can be expected if you don’t reclaim any wort from the counterflow chiller.
maximum safe Flow rate
The maximum safe flow rate for the water and wort are 6 and 3L per minute respectively. However, your ground water temperature is the rate determining factor. We recommend setting the water to between 4 and 6L per min and start reducing the wort flow from 3L per minute until the desired wort out temperature is reached.