immersion chiller - bottom up or top down

[kwazulu]

I built my chiller (10mm copper) so the cold water goes into the coils at the top, but reading Graham Wheeler's "Brew your own British real ale", he notes the cold water should go in through the bottom coils first. Its been easy to get my wort down to about 25/26C in current config, but struggling to get lower than that even when the tap water temp is lower than 20C. I am planning on switching the connectors around for the next brew but was wondering, does anyone know if it really matters?

fwiw - I have been _gently_ stirring the wort while chilling.

thanks in advance.

[Blackaddler]

Bottom up and stirring, to move the hot wort over the coils.

Just put one hand on the outlet pipe, and you can feel how quickly it goes cool if you stop stirring.

The nearer the wort temperature gets to that of the cooling medium [tap water] temperature, then the cooling effect gets less and less. Unless you can get some really cold water from somewhere [eg. a chiller], you're always going to struggle with the last few degrees.

There's a graph to illustrate it somewhere .

[kwazulu]

Swapped the hoses round on my chiller for yesterday's brew and gently stirred throughout; chilled it faster and lower than I have previously managed to. Result!