Experimenting with a faster way to immersion cool

For years I've used a simple copper wort chiller and had good luck and quick chills. However, that was when I lived in the land where tasty and cold water came out of my taps. Here in South Texas, where we get liquid limestone barely below ambient air temps out of our taps it wasn't nearly as effective.

One thing I've done and it was some help was using a second immersion chiller in a bucket of water and then placing ice in the bucket to chill the water before it passes through the chiller in the kettle. This was still not very good and I wished I could cool the water down further. The ice was a frozen water jug. The exchange of heat and the mass of the copper, etc. in the bucket meant that it wasn't getting the water much below tap temp.

Salt water freezes lower than regular water, (this is the principle behind adding rock salt to an ice cream freezer), so I added sea salt to boiling tap water until no more salt would dissolve. This water was placed in a water jug and dropped in my deep freezer.

I used it a couple days ago and the temperature dropped from just off a boil and down to under 140F in just a few minutes--I didn't expect it to be so quick so I didn't clock it. I literally killed the flame, hooked hoses to the boiled chiller, turned on the water, dropped in the ice jug, checked for leaks and run off location, then when I checked the wort it was at 140F and dropping like a rock. It was beautifully clear too. Of course, once the wort was down to about 85F the jug was warm and melted so the effect was lost--and the last few degrees took far longer than the first 125 deg. I will make another one to finish up the next batch and also clock results.

I used the brine jug, yesterday, to cool a fermenter in a swamp cooler tub--and it worked great. I put it back in the freezer with another regular water jug to refreeze. The other jug is rock solid and the brine is still not frozen and down to -11C (around 12F, which I checked with a calibrated upper-end digital thermometer to make sure).

I expected when the water froze for the salt to drop out of solution but it is back in solution when the water melts.

Someone will tell me it is my imagination and it may well be. However, I thought I would post the idea here and see if others want to try it.

You don't have to dissolve the salt in boiling water. Almost as much will dissolve in cold water. The little extra will come out of solution as it cools.

alien said:

You don't have to dissolve the salt in boiling water. Almost as much will dissolve in cold water. The little extra will come out of solution as it cools.

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I'm not a scientist. I only play one on the internet. I had forgotten that when I did it. Here is Texas it is usually sugar that we are trying to dissolve in a liquid. I had a brain fart while doing it and assumed it would work better with boiled water. Live and learn!

I've done the pre chiller and it's not so great.

Much better is using a cheap garden pump to recirulate ice water through the immersion chiller in the brew pot. Use tap water to get the initial cooling. Then change over to the pump and ice water. With ice water you can go to whatever temp you want in no time.

In any case, stiring the wort (whirlpool) raises the effectiveness of an immersion chiller. So always stir.

Sorry, not buying it. I think you’re backing up. The ice will cool more than the saltwater.

You’d think the saltwater would absorb more heat. The specific heat of ice is .5 cal/g right. Water is 1.

But this ignores the heat of fusion. As water freezes it gives off 80 cal/g. That’s a bunch. http://en.wikipedia.org/wiki/Enthalpy_of_fusion

Look at it in reverse. It takes as much energy to go from 32F ice to 32F water as it does to go from 32F water to 176 F.

I hope I got all that right.

Wynne-R said:

Sorry, not buying it. I think you’re backing up. The ice will cool more than the saltwater.

You’d think the saltwater would absorb more heat. The specific heat of ice is .5 cal/g right. Water is 1.

But this ignores the heat of fusion. As water freezes it gives off 80 cal/g. That’s a bunch. http://en.wikipedia.org/wiki/Enthalpy_of_fusion

Look at it in reverse. It takes as much energy to go from 32F ice to 32F water as it does to go from 32F water to 176 F.

I hope I got all that right.

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I'm not trying to sell it. I'm sharing what I tried and what I observed so others can experiment with it or so others more knowledgeable can interpret what I observed or correct my assumption.

BTW, I'm not using the salwater until it is fully frozen.

just to be clear... your putting a plastic jug filled with frozen ice water directly into the brewpot?

I believe if you are using a frozen jug to chill you will get the same results without the salt. If you plan on using a second jug (not recommended) make sure it is very clean and sanitized before dropping it in because you will be near the temperature that will allow bacteria to take hold.

maida7 said:

just to be clear... your putting a plastic jug filled with frozen ice water directly into the brewpot?

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Not even close. I am using the frozen jug in the bucket with the pre-chiller. It is to cool the water going through the worth chiller.

Now that I re-read it I realize it was not clear. I used a wort chiller with the cooling water passing through a pre-chiller coil. The pre-chiller is in a bucket of water into which I placed a jug of frozen saltwater. The purpose is to lower the temperature of the jug below the usual freezing temperature of fresh water and so that it will hopefully melt slower.

cluckk said:

Now that I re-read it I realize it was not clear. I used a wort chiller with the cooling water passing through a pre-chiller coil. The pre-chiller is in a bucket of water into which I placed a jug of frozen saltwater. The purpose is to lower the temperature of the jug below the usual freezing temperature of fresh water and so that it will hopefully melt slower.

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you would be much much much better served by using a small cheap pump to recirculate the ice water from the bucket through the immersion chiller in the brew pot and back to the bucket. In my experience this method is vastly superior to using a pre-chiller.

oh and don't forget to stir the brew pot while you're chilling. The stiring makes a huge difference in how fast a immersion chiller works.

maida7 said:

you would be much much much better served by using a small cheap pump to recirculate the ice water from the bucket through the immersion chiller in the brew pot and back to the bucket. In my experience this method is vastly superior to using a pre-chiller.

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Yes, I could get better results by buying a pump and setting it up. I could also get great results with (fill in the blank with any number of devices I don't have). The post is an experiment to get more efficiency with what I already have and not a request for how to do it better with more expense and more technology. Thanks anyways.

cluckk said:

Yes, I could get better results by buying a pump and setting it up. I could also get great results with (fill in the blank with any number of devices I don't have). The post is an experiment to get more efficiency with what I already have and not a request for how to do it better with more expense and more technology. Thanks anyways.

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I though you were seeking a "faster way to immersion cool". Do whatever you want.

I may try that later when I can afford it.

Are you doing full boil AG
If not why not try ice in the wort. If you are careful and freeze water in sealed containers to keep out germs it will cool your wort faster than any other method

Full boil AG--yes. Ice in wort, not if my life depended on it.

I think that is the funniest thing. Full boil AG you don't need to add any water.
But I have added ice to extract kits and partial mashes SEVERAL times and yet i am still alive and have not had any infected batches. I think the ice on wort mith will die a slow death just like you MUST rack to secondary for clearing your beer.

sorry for the hijack.

I don't understand what the salt is buying you here.

A jug of water placed in a freezer will freeze solid, and end up at the same temperature as a jug of salt water. The jug of salt water will freeze at a lower temperature, but once both have been in the freezer for a day or so, they'll both be frozen solid, and equally cold. Adding the salt doesn't allow the ice to get any colder - it simply means the phase conversion occurs at a lower temperature.

If you added salt to the WATER in the bucket into which you're dropping your pre-chiller coil and the frozen jug of water, then I can see how THAT might make a difference, since you could get that water down below 32° F and have it still be liquid (allowing a more efficient heat exchange with the coils than unsalted water at 32° F or ice that is frozen solid and which would be difficult to keep in full contact with the entire coil surface area), but I don't think the salt in the ice in the frozen jug is buying you anything at all.

Instead of putting the jug of ice in the pre-chiller bucket of water, why not put ice and salt directly into the pre-chiller bucket, maybe top off with water if necessary. Ya know, like old time ice cream making using the bucket of rock salt and ice. That gets cold...

cluckk said:

I may try that later when I can afford it.

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The pump is not very expensive. Something like this should work fine.

So, do you recirculate the water back into the same container or start with a very large container of ice water?

cluckk said:

So, do you recirculate the water back into the same container or start with a very large container of ice water?

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Recirculate back to the same container with the ice water.

I'd recommend using tap water for the first 100F then switch to the pump and ice water.

And don't forget to stir. Stiring (aka whirlpool) is very important.

Much better is using a cheap garden pump to recirulate ice water through the immersion chiller in the brew pot. Use tap water to get the initial cooling. Then change over to the pump and ice water. With ice water you can go to whatever temp you want in no time.

In any case, stiring the wort (whirlpool) raises the effectiveness of an immersion chiller. So always stir.

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This was going to be my exact post. I tried putting salt in my ice-water bucket once, but I don't think it's worth it. Stirring makes a huge difference; my effort is better spent stirring.

If you can recirculate the pre-chiller (or just have someone move it around) it will help also. The water around the pre-chiller heats, and then doesn't cool as well. moving the water in the pre-chiller bucket will help as much as stiring/moving the wort.

Sorry cluckk, I totally misinterpreted your first post. As long as the brine is freezing you’re fine. It will absorb slightly more heat than the plain water, but be a lot harder to freeze.

Heat transfer is proportional to the difference in temperature. So if the brine freezes at 12F and your freezer is at 10F it’s going to take a while.

I agree with maida7. A closed system would be way more efficient. That’s how I do it, with an Eco396 pump.

cluckk said:

So, do you recirculate the water back into the same container or start with a very large container of ice water?

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I live in Tucson Arizona, so I understand what you are going through.

So here is my recommendation.

1. Place a 50' immersion chiller in the wort.
2. Get/buy/steal a pump, and place it in a large tub or a large cooler.
3. Fill the tub with tap water and add some ice, 15 minutes before flame out.
4. At flame out, turn on the pump, and start chilling.
5. Absolutely stir, I made an automatic stirrer out of an electric screw driver.
6. DO NOT RECIRCULATE, water a tree. Recirculating just heats up your cold water. Not good.
7. After about 6 minutes my 10 gallons is below 140 degrees.
8. Now add more ice to the tub. And if necessary more water. I use a lot of water, not very green of me, put my trees like it, and they are green.
9. I have a kegerator, the freezer part is dedicated to making ice.
10. 10 gallons chilled to 60 degrees in 20 minutes.

This is my Texas Recommendation

Place a 50' immersion chiller in the wort. I wait till flame out...some people put it in earlier to sanitize it 'more' or something

Get/buy/steal a pump, and place it in a large tub or a large cooler.

Put some tap water in the tub but no ice yet.

At flame out, run tap water through the chiller. Stir continuously, but don't splash. If you run the water full-blast, it will cool the best. If you want to save water, you can slow the flow down, but I just capture the water in buckets and 'spill' it on my parched lawn after it cools down. My city's water restrictions may not allow watering the lawn in the summer, but say nothing about brewing and clumsiness.

Monitor the output temperature. When the output temperature drops from "OMG burning" to "I can hold my finger in it now" but still hotter than "piss warm", dump ice into tub, turn on the pump, and start pumping ice water.

Do not recirculate YET. Monitor the output temperature of the chiller. If the water is coming out of the chiller warmer than your tap water, discard the water from the chiller, and keep topping off your ice bucket with cooler tap water.

As soon as the output temperature of the chiller is comparable to the output temperature of your tap water (i.e. 'piss warm' here in TX), then start recirculating the water instead of discarding it. There's no point using warmer tap water if the chiller water is coming out cooler than the tap water.

Result: 5 gallons chilled to pitch temps in like 10 minutes, with optimal ice and water usage. It takes me about 2 Target bags of ice...maybe 15lb? But it's free from the fridge.

These machines are your friend...

cluckk said:

I may try that later when I can afford it.

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You don't need a high end pump for this, like a march, etc. Use an aquarium or pond pump, I think I am using about a $30 pump to make this happen when I used this technique. I would have a 5 gallon bucket with ice and water. I'd pump it through the IC back into the bucket. The problem is when I am doing 10+ gallon brews, I went through more than a bag of ice. The cost of the ice will soon outweigh the cost of the pump.

Even with cold water the last 20-30 degrees will always take too long. I used to live in cold tap country and still felt the wait was too long. I would use tap water to bring the temp down to 125 then recirculate ice water to get it the rest of the way. I also did the freeze bottle thing to immerse in the chilled water bucket. The problem is like the one in an IC chiller: A boundary layer forms where the coldest water and hottest wort no longer come into contact. With an IC it is simply a matter of agitating the IC to keep wort moving around. Keeping the icy water effective in cooling when in a water bottle is not as easy.

My next scheme to make the cooling fast and cheap is to try and pre-chiller. In the bucket with the pre-chiller will be ice filled water bottles and a bag of ice. I will also place my pond pump in this bucket to keep water circulating and prevent boundary layers. I will also be agitating both the pre-ciller and IC to speed things up. My goal is 12 gallons of wort chilled in under 10 minutes.

BetterSense said:

This is my Texas Recommendation

Place a 50' immersion chiller in the wort. I wait till flame out...some people put it in earlier to sanitize it 'more' or something

Get/buy/steal a pump, and place it in a large tub or a large cooler.

Put some tap water in the tub but no ice yet.

At flame out, run tap water through the chiller. Stir continuously, but don't splash. If you run the water full-blast, it will cool the best. If you want to save water, you can slow the flow down, but I just capture the water in buckets and 'spill' it on my parched lawn after it cools down. My city's water restrictions may not allow watering the lawn in the summer, but say nothing about brewing and clumsiness.

Monitor the output temperature. When the output temperature drops from "OMG burning" to "I can hold my finger in it now" but still hotter than "piss warm", dump ice into tub, turn on the pump, and start pumping ice water.

Do not recirculate YET. Monitor the output temperature of the chiller. If the water is coming out of the chiller warmer than your tap water, discard the water from the chiller, and keep topping off your ice bucket with cooler tap water.

As soon as the output temperature of the chiller is comparable to the output temperature of your tap water (i.e. 'piss warm' here in TX), then start recirculating the water instead of discarding it. There's no point using warmer tap water if the chiller water is coming out cooler than the tap water.

Result: 5 gallons chilled to pitch temps in like 10 minutes, with optimal ice and water usage. It takes me about 2 Target bags of ice...maybe 15lb? But it's free from the fridge.

Click to expand...

I really like this idea:
"As soon as the output temperature of the chiller is comparable to the output temperature of your tap water (i.e. 'piss warm' here in TX), then start recirculating the water instead of discarding it. There's no point using warmer tap water if the chiller water is coming out cooler than the tap water."

This just became part of my SOP.

Thanks.