Just to make sure, here's how I proceed for a 13l batch:
- Heat ~19l at 78C (173F)
- Transfer 12l to the MLT (after pre-heating), add grain => should be at 67C (153F).
- Heat the rest of water (7liters) at 173F
- After 50min, I pour 2 liters of wort and put it back (manualy) to the MLT, just...