I recently got a new single coil immersion wort cooler and while thinking about plumbing it in I came up with a question.
Which way should the water flow, should the cold water go in the bottom of the coil and flow out the top or the other way round.
From an ex physicist's point of view it seems fairly obvious that if the wort temperature was the same at all depths then the direction of flow would not be relevant. But, in a real container of wort that was cooling I would expect the temperature of the liquid to be lower at the bottom than at the top, which makes the situation a lot more complicated.
I suspect I am thinking about this to much but has anyone considered this difference or done any experiments.