My MLT has a false bottom, and I have quite a bit of wort in the recirculation plumbing at any given time. In fact, I have wort sitting about an inch above the grain bed that doesn't contact the mash until it drains into it.
When I calculate mash thickness, should I include *all* my wort (i.e. the volume of my strike water), or just the wort that is in contact with the grains?
If it is just the wort in contact with the grains, I would have to subtract out 2 gallons from my false bottom, a gallon or more for my plumbing, and about a gallon for the wort abobve the top surface of the grain.