Thank you for your suggestion. Yes, from the top of the waterline to the base of the bath is approximately 15cm. I do occasionally use a skewer to keep things in a vertical position, or use some of the excess plastic from the evacuated vacuum bag anchored underneath the waterbath lid to keep the food in an appropriate position.
Sure forced circulation does make a difference, see http://forums.egulle...ost__p__1729644 . My stockpot is 9L nominally, I use 7-8L water and an indoor fountain pump, and I never noticed a problem with meat cuts up to 700g or up to 3 bags, hanging vertical on a skewer (see http://forums.egulle...ost__p__1699134 ). If your bag is not in a vertical position, it might impede convection. As your bath is a bit shallow (post #3304) you might at least bring your bag to an oblique position by placing some weight in the bottom of the bag, see post #3384.
My waterbath also came with a metal grill which has about 2cm clearance underneath, so that incase an item was to sink to the bottom of the tank, it wouldn't sit against any heaters, and would also allow currents of water to pass beneath it.
However, I would be interested in an effective method of forced convection in water of a temperature up to 80C. I know people suggest air stones... but how effective are they at regulating and circulating 7 litres of water to be at complete uniform temperature??
Edited by Guy MovingOn, 24 March 2010 - 10:33 PM.