How deep should sap be?

[oldboyscout]

I have a 2x3x7" pan and am wondering how deep I should keep the sap in while boiling. Any thoughts? Does deeper take longer?

[jmayerl]

run it as comfortably as you can. the more shallow, the faster boil. depending on how hot the fire is underneath makes a difference also. I run a pretty hot fire and usually run 1/2-3/4" deep, but if im doing anything else at the time I'll go 1-1 1/2" because things happen quick when it nears syrup.

[oldboyscout]

holy cow a half inch? You're brave!
I did figure shallow was better though. I guess I'll have to babysit it. I got used to doing yardwork while it was boiling 3-4" deep.