I am going to be moving in a few weeks so i probably wont be able to brew for a while so i was thinking about trying to get two brews done in one session. I am might start the second mash half way through my first boil, then drain once i pitch. That seems like a i might get myself into a mess though too much going on at once. Would it be possible to to re-mash/sparge the same grains and then maybe do a partial boil and add some extract? If so how would i calculate how much gravity i would be getting out of it how much extract to add?