Distilling spirits

Into each cask or hogshead, throw nine gallons of water heated to ninety degrees of Farenheit’s thermometer, to which add forty pounds of Indian corn meal; agitate the mass briskly, and let it stand two hours, that it may open and prepare the grain for dissolution; now twelve gallons of boiling water are added, and briskly worked with the oar, then suffered to stand fifteen minutes – on the top of this, four gallons of luke-warm water are gently poured, and ten pounds of malt gently worked on the top, so as not to intermix with the corn meal, which is in that state suffered to stand thirty minutes, then fourteen gallons more of boiling water are added to the mass, and worked as before: this in that state is suffered to stand sixty minutes, then forty pounds of rye meal are now added, and worked well, and just as before the whole mass is suffered to stand from two to four hours, in proportion to the state of the weather: the calculation is, when cold water filled to within six inches of the top of the cask, will bring down the whole mass to seventy-five degrees. It is now yeasted … covered … and left until fit for the still

-Theory and Practice of Distilling by Michael Krafft, 1804

I brew my own beer- my understanding is that distilling is just one step further. After brewing your beer you just boil out the alcohol. Obviously your ABV will determine how much you get per quantity.