Tip for cooling with an ice bath

[gr8shandini]

I've seen a few questions on here recently regarding cooling wort using an ice bath. I've got an immersion chiller for beer, but when I make stock I use the ice bath method. One day, it triggered a memory from way back in thermodynamics class where they demonstrated that the rate of heat transfer is proportional to the difference in temperatures between the media.

Using that information, I was able to significantly speed up the cooling by saving the ice for the end of the process. Using a bath of just cold tap water, the temperature comes down from boiling to about 120 in just a few minutes. At that point, I set up an ice bath in the other half of the sink and transfer the pot over. Using this method, I'm able to get into the 70s in about 15-20 minutes where it would take 40 or more just using a single ice bath.

Of course, if you have plenty of ice, using it from the get go would be best. But if you only have one shot at it, save the ice for when it will do the most good.

 

[tally350z]

What temp are you able to get down to with your Immersion chiller?

 

[verbhertz]

Good tip for those without a cooler.

 

[Mongzilla]

You could add salt to the ices bath to drop its freezing point, as long as it would not damage your gear and did not get in the wart.

 

[gr8shandini]

What temp are you able to get down to with your Immersion chiller?

I use the IC on beer since I normally brew all-grain and trying to chill 5 gallons with an ice bath is pretty dicey for no other reason than just trying to haul that much scalding hot liquid around.

But to answer your question, it normally takes me about 10 or 12 minutes to get below 90, but the final temp depends on the temperature of the water supply. In my area, that varies from about 55 degrees in the winter to about 80 in the dead of summer. I can normally get within 3 to 5 degrees of the water temp within about 30 mins. That usually gets me down to pitching temps fairly quick, but in the summer, I have to give up and just throw it in the fermentation chamber a little warmer than I like. The yeast don't really get to doing their thing for a few hours anyway, so I figure the damage is minimal.

 

[nasa258e]

about 80 in the dead of summer.

Ewww

 

[gr8shandini]

You could add salt to the ices bath to drop its freezing point, as long as it would not damage your gear and did not get in the wart.

I don't think that would really buy you much. It's important if you're doing something like making ice cream which has a freezing point slightly below that of normal water because of all the dissolved sugars. But in terms of cooling something hot, the magic of the ice is the energy required to change from the solid to liquid phase. It takes far more heat to take water from 32F to 33, than to go from 31 to 32 or 33 to 34. So the fact that you can chill a brine solution below the normal freezing point doesn't matter as much as the actual melting of the ice.

 

[BrutalBrew]

This is how I do it. Salt does help. It slows the melting of the ice. BUT its not so much of a big differents that its worth the money of how much salt you need to be effective. I use a tub that gives me about 8" clearance on each side of my pot set in the middle. I sit it on a metal pie pan upside down in bottom of tub. It keeps bottom of pot from touching plastic bottom and helps water circulation. I add 2 large bags of ice (22lbs each i think) Then I add cold water from garden hose untill the water level is level with wort in pot. You can tell because the pot will start to float if you fill up more that pot has in it. You DONT want that, but no big deal if slightly above pot level. You can hold down pot with one hand. Using other hand take a spatula and stir the water carefully in 1 direction to keep the ice water rotating around your pot. I run a thermometer in the small hole in lid. I cool 5.5 gallon batchs to 65-70 in 15 mins constantly. BUT by the time you have cooled 2 or 3 batchs you could have built your own submersion chiller for same amount of money youve spent on ice.

 

[unionrdr]

I do a cold water bath 1st to scrub off some of the initial heat. Then drain the sink,put the pot in,& fill the sink to the top with ice. Then top that off with cold water. You get the maximum amount of ice that way. I can chill down to about 70F in 20 minutes,which is great for reducing/eliminating chill haze when the bottles go into the fridge.

 

[temptnmonkey]

Good advice. I do this too. I also try to get the wort moving in a whirlpool each time I put it in the water.

 

[tonyc318]

This is how I do it. Salt does help. It slows the melting of the ice. BUT its not so much of a big differents that its worth the money of how much salt you need to be effective. I use a tub that gives me about 8" clearance on each side of my pot set in the middle. I sit it on a metal pie pan upside down in bottom of tub. It keeps bottom of pot from touching plastic bottom and helps water circulation. I add 2 large bags of ice (22lbs each i think) Then I add cold water from garden hose untill the water level is level with wort in pot. You can tell because the pot will start to float if you fill up more that pot has in it. You DONT want that, but no big deal if slightly above pot level. You can hold down pot with one hand. Using other hand take a spatula and stir the water carefully in 1 direction to keep the ice water rotating around your pot. I run a thermometer in the small hole in lid. I cool 5.5 gallon batchs to 65-70 in 15 mins constantly. BUT by the time you have cooled 2 or 3 batchs you could have built your own submersion chiller for same amount of money youve spent on ice.

You cool 5 gallon batches in an ice bath in 20 mins? That's incredible and a ton of ice!

 

[duboman]

You cool 5 gallon batches in an ice bath in 20 mins? That's incredible and a ton of ice!

I agree, I generally do about 30-40 batches a year and 22lb bags of ice are about 5 bucks which translates into $300-400, that's a lot of IC's or some super nice 15g SS kettles!

 

[bigbeergeek]

Salt does help. It slows the melting of the ice.

Not to nitpick, but salt speeds the melting of ice -- that's why they spread it on frozen roads etc.

 

[jwplessner]

But to answer your question, it normally takes me about 10 or 12 minutes to get below 90, but the final temp depends on the temperature of the water supply. In my area, that varies from about 55 degrees in the winter to about 80 in the dead of summer. I can normally get within 3 to 5 degrees of the water temp within about 30 mins. That usually gets me down to pitching temps fairly quick, but in the summer, I have to give up and just throw it in the fermentation chamber a little warmer than I like. The yeast don't really get to doing their thing for a few hours anyway, so I figure the damage is minimal.

Yep, Philly tap water gets too hot in July-August for immersion chiller only. I started to use a pond pump plus ice water to lose those last 10-15 degrees. I disconnect the immersion chiller from the tap and connect the outlet hose to the pump, then run ice water the opposite way through the chiller.

 

[unionrdr]

I only need about 1/2 a 20lb bag of ice in the sink around the BK to get down to about 70F in that 20 minutes. But I do stir the wort ocassinaly while the sink is too full of ice to stir.

 

[Andrew5329]

You may not want to sit there babysitting it, but agitating the ice bath does speed up the process of cooling considerably, otherwise you get a layer of warm water surrounding your pot.

 

[tonyc318]

Just brewed today. Did wirlpool of wort while stiring water on outside of BK. Also drained and added more cold water. Did partial boil so added it to cold water in the FV. Hit 62 for my temp before pitching my yeast.

 

[Big-R]

Yep, Philly tap water gets too hot in July-August for immersion chiller only. I started to use a pond pump plus ice water to lose those last 10-15 degrees. I disconnect the immersion chiller from the tap and connect the outlet hose to the pump, then run ice water the opposite way through the chiller.

I was wondering in about the pump idea! I made a IC with larger diameter pipe then others use. It works really well, but I can't catch all that water. In a MI winter is took 15min on tap water to get it to 70. I just moved to Seattle, where water costs double of what it did in MI, to that's the concern for me.

Good thought guys, thanks!

 

[Jwood]

its a matter of free vs. forced convection cooling. You will get the best results if you stir the wort continuously as well as move the the water in the ice bath around (while keeping the ice bath as cold as possible). Material matters as well, SS pot, aluminum pot? It all makes a difference.

I continuously stir the wort (slowly) and always keep ice in the sink and i can get it down to 60's in about 35 minutes or so. (SS pot)


Of course, on that note, once i get a bigger pot that will fit an immersion chiller i will get one without a doubt.

 

[gr8shandini]

Yep, Philly tap water gets too hot in July-August for immersion chiller only. I started to use a pond pump plus ice water to lose those last 10-15 degrees. I disconnect the immersion chiller from the tap and connect the outlet hose to the pump, then run ice water the opposite way through the chiller.

Yeah, I've been thinking of doing that as well. However, I'm in the process of upgrading to a 10 gallon brewhouse and I think I'm going to opt for a plate chiller instead. Then I'll use the IC I already have in a bucket of ice toward the end to pre-chill the water.

 

[unionrdr]

I've been thinking the last winter of making a dual coil chiller myself. One side's tap input goes into the other side of the sink in ice water before it goes into the coil in the hot wort,then into the 1st sinks drain.
Should cool faster that way.

 

[JDFlow]

Using a bath of just cold tap water, the temperature comes down from boiling to about 120 in just a few minutes. At that point, I set up an ice bath in the other half of the sink and transfer the pot over. Using this method, I'm able to get into the 70s in about 15-20 minutes...

This works, tried it yesterday. Thanks for the info, gr8shandini!