Since I don't have a refractometer, can my hydrometer measure pre-boil runnings, at the higher mash temps? Do the temperature adjustment algorithims apply at temps reaching 150F. Do I need to to cool preboil samples?
I'm brewing my first all-grain Sunday. I have done months of research and feel confident all will go well, but want to clear up some of the finer points before zero hour. Please advise.