I make beer on a 10 gallon (45 litre scale) and after boiling the sweet liquor with the hops it has to be cooled quickly to get a hot break that
precipitates out the proteins to leave a clear liquor ready for fermentation.
I use a 25 litre brewing bucket and a small garden pump that pumps the water through a submerged soft copper coil in the hot liquor tank. I cool the
cold liquor tank by using giant ice cubes made by filling plastic shoe storage boxes with water and freezing them down in my deep freeze. I tried
plastic drink bottles like Peach but the heat transfer due to the insulating effect of the plastic was too slow. I have to use 15 - 20kg of ice per
batch.