I'm still a newbie home brewer who has been using the ice bath method of cooling hot wort. For my last batch, I made a slight variation that made a huge difference in the cooling time of my wort in this method.
While I waited for my wort boil, I filled up a bathtub with about 6 inches of cold water. Earlier in the day, I bought four of those huge bags of ice you can get at any gas station for a buck each. About an hour before it was time to chill my wort, I dumped two of these bags of ice into the tub. By the time it was time to chill my wort, the bath water temperature was a few degrees from freezing point with a large amount of ice still floating.
I added the hot brew pot to the bath, then added the other two bags at ice. Throughout the chilling process, the bath water remained a constant temperature, as the melting ice kept the water at near freezing temperature. After a half hour, my wort was at 53 degrees! Crap. Too low! Unfortunately, I underestimated how much quicker it would be so I don't have the exact timing it took to get the wort down to an ideal 70 to 80 degree pitching temperature.
Some theory crafting: Once the water hits near freezing it will remain so as long as there is still solid ice melting. With the volume of water much greater than the 2.5 gallons of wort in the brew pot, the pre-chilled bath water effectively becomes a heat sink at a stable near freezing temperature as long as solid ice remains.
If you add ice while your water is at a cool room temperature, it is cooling both the wort and the water.
Tip: watch for buoyancy on your brew pot! It could float away and I had to put a couple bricks on top of the lid so it would stay submerged.
While I waited for my wort boil, I filled up a bathtub with about 6 inches of cold water. Earlier in the day, I bought four of those huge bags of ice you can get at any gas station for a buck each. About an hour before it was time to chill my wort, I dumped two of these bags of ice into the tub. By the time it was time to chill my wort, the bath water temperature was a few degrees from freezing point with a large amount of ice still floating.
I added the hot brew pot to the bath, then added the other two bags at ice. Throughout the chilling process, the bath water remained a constant temperature, as the melting ice kept the water at near freezing temperature. After a half hour, my wort was at 53 degrees! Crap. Too low! Unfortunately, I underestimated how much quicker it would be so I don't have the exact timing it took to get the wort down to an ideal 70 to 80 degree pitching temperature.
Some theory crafting: Once the water hits near freezing it will remain so as long as there is still solid ice melting. With the volume of water much greater than the 2.5 gallons of wort in the brew pot, the pre-chilled bath water effectively becomes a heat sink at a stable near freezing temperature as long as solid ice remains.
If you add ice while your water is at a cool room temperature, it is cooling both the wort and the water.
Tip: watch for buoyancy on your brew pot! It could float away and I had to put a couple bricks on top of the lid so it would stay submerged.