I always run off a 1/2 gallon jug from the mash tun at the end of the sparge. It is usually around 1.015. I freeze this and thaw out a few days before the next brew day. I boil this for 20 mins with some added DME to get around 1.040 to my starter 24 hrs prior to pitching. I pitch it all at high krausen...to my sanitized yeast harvesting ball jar (1/4 qt) and my fermenter...just thought I'd share