Double immersion chiller?

I was a bit frustrated yesterday by the time it took to get my brew down to reasonable temperatures using my immersion chiller. With the temps in the 80-90s in DC, reasonable temperature meant around 80F (ground water was around 75), which was acceptable for my saison, but not for any other brews.

I was thinking of getting another immersion chiller to use first, which I would immerse in a bucket of ice water, and then lead that chilled water to a secondary chiller submerged in the wort. I’m thinking I will be able to avoid using a pump this way, and can just use the standard tubing thats provided. I really want to be able to get the internal temps down far enough for lager pitching temps.

It seems like a pretty simple idea, and I know others have had success using additional counterflow chillers in ice water, but I just wanted a sanity check and see if others have done/tried this.

I do something similar. My hose feed to the immersion chiller is a 50’ coil hose and put that in a cooler full of ice on its way to the chiller. works like a charm.

If you have a fridge or chest freezer to lager, you can chill it as cool as it will go, then you can cap your carboy with an undrilled bung or put the lid on your bucket and leave over night to cool down to temp. Then in the morning, aerate, and pitch your yeast.

I was not able to get satisfactory results from a pre-chiller even when I sat and stirred the ice water bath and kept the flow really low, but with a $20 Harbor Freight pond pump recirculating ice water through the IC, I can easily get 12-18 gallons of wort down into the low 60s.

I was originally thinking about doing this but I didn’t know about the type of pump (brand, power), or how I would hook it up. The double immersion chiller seemed to make sense in my head how to hook it up so my brain went there instead.

I would, however, prefer to have a cheaper more effective method. I see a 14.99 264 GPH fountain pump from Harbor freight, which would be great if that’s good enough. Not entirely sure how I would hook it up though. How is yours hooked up?

I imagine that with the recirculation, you chill the wort down with standard tap water before using the ice water right?

Thanks for the help

[quote=“chaglund”]I see a 14.99 264 GPH fountain pump from Harbor freight, which would be great if that’s good enough. Not entirely sure how I would hook it up though. How is yours hooked up? I imagine that with the recirculation, you chill the wort down with standard tap water before using the ice water right?[/quote]264 gph is plenty (same as the one I have). I chill with groundwater down to 100-110F with about 20 gallons total, then put the pump in the bottom of a 5-gal bucket and cover it with ice, add water to the top of the pump, shut off the hose and attach the IC directly to the pump outlet (I put a two-foot piece off the male end of an old garden hose and clamped it to the pump’s post), then put the IC’s outlet down into the bucket and turn on the pump. The returning IC water has to percolate down through the ice to get to the pump, so the water going into the IC is very cold. Every now and then I’ll add more ice and pull the return line out and reduce the water level in the bucket.

I do this on my 5 gallon boils. I built two identical immersion chillers and put standard hose threads on them. I cut up an old hose and added new ends to make short sections of hose to go from tap to chiller in bucket of ice water then out to chiller in wort. It has worked very well for me. I will occasionally stir the ice water and find the “out” end gets very cold and brings the wort temp down fast.

The way I made my two chillers I can stack one on top of the other then connect and out to an in and have one giant chiller for a 10 gallon boil.

Sometimes I coil my hose in a batch of ice water. If I have extra ice in the house. I need to do a test with a timer to decide if it makes a worth while difference

Any little bit would help, but I doubt you get much of a temperature exchange across rubber. Not saying there is anything wrong with what you are doing but copper would definitely pick up more of the cold temps.

And I only would think of this because back in college I had a roommate who is now a chemical engineer and after taking a class on thermo dynamics was standing in line at a fast food place and started mentally calculating the heat transfer rate of the burger, through the wrapper, under a heat lamp.

Immersing the fermentor with the 80 degree wort in a bucket of ice water for about 5 minutes also works to get it down into the 60s.

FWIW, I use an IC for 20 gallon batches. Once the wort is within 10 degrees of the water supply temp, I don’t bother with the IC any more, there just isn’t enough temp difference between the chiller and the water supply to efficiently chill any further. That is the point I transfer to fermentors and place them in the bucket of ice water to get it down to where I want it.

Tap water with the IC until the wort is around 100-120 and then stop the tap water and connect a submersible pump in ice water to bring the wort down as low as you need.

Don’t buy a “pond pump” unless it is clearly over 1/3HP. Most pond pumps are rated for a lot of flow but no power, mainly for low resistance situations such as a little fountain at most. This means you may not get a good flow if the pump doesn’t have the guts, and a regular IC has a great amount of resistance. Get a decent submersible from Harbor Freight or the other cheap tool companies for about $50 and you’ll be happy. Mine works like new and has to be 7 years old now.

Also, pre-chillers are notoriously inefficient. Get a good IC and a good submersible pump and put the chill water where it works the best.

[quote=“Dean Palmer”]Don’t buy a “pond pump” unless it is clearly over 1/3HP. Most pond pumps are rated for a lot of flow but no power, mainly for low resistance situations such as a little fountain at most. This means you may not get a good flow if the pump doesn’t have the guts, and a regular IC has a great amount of resistance.[/quote]The $20 264-gph pond pump from Harbor Freight has eight feet of head and has no problem pushing a steady flow through a 50’ 1/2" diameter IC about five feet above the ice bucket. I’ve used mine hundreds of times and it’s still going strong, but YMMV of course.

That’s the kind of rating you need. Eight feet of head pressure works.

Good, because I ordered one an hour ago.

Thanks for all the advice! Looking forward to the new process.