[blatz]

Even in the heat of summer?  Where do you live Alaska?

assuming directed at me - no, i live in the opposite - south florida.

the first CFC with 75-80df groundwater knocks the wort to 90-100df approx, the second one, being fed with 36-40df ice water loop knocks it down below 50, lower dependent on how much i restrict the wort flow with a ball valve.

In the heat of summer, for a lager, i'll need 30-40# of ice, 20-30# for an ale.  During the winter 10-20# less respectively.

[blatz]

btw as another poster mentioned, the same effect can be achieved with an IC by using hosewater to knock down to ~100df and then switching from the hose to a sump pump recirculating a loop of ice water until it hits your desired pitching temp.

[jeffy]

btw as another poster mentioned, the same effect can be achieved with an IC by using hosewater to knock down to ~100df and then switching from the hose to a sump pump recirculating a loop of ice water until it hits your desired pitching temp.

Yes, I'm also in Florida and I chill the kettle with ground water to less than 100 first.  It depends on the time I have - sometimes I can get it to 85.  Then I switch to recirculating ice water, but I usually just run the chilled wort straight into the fermenters instead of trying to cool the whole kettle.  One 20# bag does 10 gallons down to the upper 50's for me.

[HoosierBrew]

btw as another poster mentioned, the same effect can be achieved with an IC by using hosewater to knock down to ~100df and then switching from the hose to a sump pump recirculating a loop of ice water until it hits your desired pitching temp.

+2

[S. cerevisiae]

Ice is amazing stuff.  It takes ~80 calories of heat to convert 1 gram of ice at 32F to 1 gram of water at 32F whereas it only takes 1 calorie of heat to raise one gram of water one degree Celsius.  This amount of energy is known as the latent heat of fusion for water.  What latent heat of fusion for water means in layman's terms is that 1 gram of ice can sink 80 degrees Celsius from 1 gram of wort during the phase change from ice to water.  A 5-gallon batch of 1.060 wort water weighs approximately 48lbs; hence, 48lbs of ice will drop 5 gallons of 1.060 wort from boiling to 20C (68F) during the phase change from ice to water, and that is before the wort and the melted ice water reach equilibrium (i.e., equalize in temperature).  Forty-eight pounds of ice is roughly 5.75 U.S. gallons of water.  If the wort is dropped from boiling to 20C during the phase change from ice at 32F to water at 32F, then we have 5.75 gallons of 32F cooling water and 5 gallons of wort at 68F before the liquids reach equilibrium, and 5.75 * 32  + 5 * 68 / 10.75 = 49F wort after the liquids reach equilibrium.  Granted, this scenario is for a 100% efficient heat exchange system, but it does illustrate the power of ice when it comes to cooling.

[Biran]

I use a recirculating immersion chiller to get it down from boiling to around 100*F.  It is in series with a prechiller that sits in a bucket.  Once I am in the 100*F range, I dump ice water into the prechiller bucket to bring it down to pitching temp.  I am usually completely chilled within an hour or so.  When it is over 100*F ambient I just chill as much as a I can and then put it in the fridge over night.

[gymrat]

I get my water down to 100 or less depending on the weather,  then switch to a pond pump and recirculate ice water. Last summer on a mid 90s day I went from boiling to 65 in half an hour.

[EThome]

My last two batches I used a cooler with ice water and a submersible utility pump connected to my IC. Used two 20 lb bags of ice (it helps having a Lang Ice House nearby) and got the wort from boiling down to 70F within 20 - 25 minutes. Wastes sooooo much less water.

I'm currently freezing gallon jugs of water in the freezer compartment of the kegerator to use next time in lieu of having to buy bags of ice. I'm hoping 4 or 5 should do the trick.