If you want to know your mash efficiency you should calculate based on pre boil volume and SG. If you want brew house efficiency then it is calculated based on the volume into your fermenter and it's SG. Starch conversion is tested by an iodine test.
thanks...and if I do a mash efficiency test I need to take into account the temp right?
Which efficiency to I compare to my presumed/expected efficiency?
thanks...and if I do a mash efficiency test I need to take into account the temp right?
Which efficiency to I compare to my presumed/expected efficiency?
Two ways to do the mash efficiency test. Refractometer with temperature corrections works well because you only need a drop or 2 of wort and it will cool quickly. The other is to take a hydrometer sample and let it cool before you drop the hydrometer in so the heat shock doesn't break the hydrometer.