thoughts on faster chilling

[itsnotrequired]

i am presently chilling with a stainless steel counterflow chiller and it takes a long time to get down to pitching temps (pumping through chiller, no gravity option). i know stainless isn't as efficient a chilling medium compared to copper and i was totally prepared to deal with a 15% or so increase in chilling times but it still seems way too long. maybe i'm just impatient but am looking at ways to speed up the process.

i have an old 25' copper immersion chiller from my extract brewing days. the last couple of brews, i've used that as a pre-chiller for my cooling water (tap water temps are about 67 degrees this time of year). i simply set the chiller in a 5 gallon bucket of ice water and away i go. this helped cooling times but still seems long. i then realized that i have a 25' stainless coil sitting around that i purchased when looking at doing 5 gallon batches on a HERMS system, thinking of getting that involved. my thoughts:

1. do nothing. keep using the copper immersion chiller for pre-chilling. stop bitching about chill times, drink a beer while chilling.

2. run the wort through the copper chiller, with the chiller in an ice bath and then on to the counterflow chiller (or vice versa). all my other stuff is stainless and i'd rather not run wort through the copper chiller.

3. build a second counterflow chiller out of the 25' stainless coil (insert the coil into a hose). stainless is pretty unforgiving to bend and with only a 10" diameter coil, i question being able to slip a hose over it. doesn't seem practical.

4. run the wort through the 25' stainless coil, submerge the coil in an ice bath and then onto the counterflow chiller (or vise versa). this is basically option 2 above but using stainless instead of copper. seems easier to clean.

5. option 4 above but also use the copper coil as a cooling water pre-chiller, in a second ice bath. this basically adds additional chilling to both the wort and the cooling water for the counterflow chiller.

i'm really leaning toward option 4, especially with running the hot wort through the counterflow chiller first and then through the ice bath. yes, it is another piece of equipment to clean but i am already flushing out the counterflow chiller and wort pump with hot water at the end of the day anyway, no great shakes to have the extra coil in there. the extra chilling with pre-chilling the cooling water seems excessive (would need to buy twice as much ice).

thoughts?

 

[jerbrew]

6) run your chilling water through the the copper coil submerged in ice water before entering your CFC and pump wort through CFC as normal.

I think this might take a bit of extra ice cooling down your chilling water before chilling your wort but I think it's the easiest and the best way to decrease your cooling times. Also make sure you are using a substantial flow rate of water. The more cooling water and the colder it is the faster you'll cool down your wort.

 

[kh54s10]

Get some liquid nitrogen. It should shorten your cooling time dramatically. But likely very expensive and potentially dangerous......

Or just experiment with the equipment you have to find the quickest solution.

 

[Bobby_M]

Prechillers are quite ineffective due to stratification in that stagnant icewater bath. You can make them better by agitating the ice bath the whole time but it's MUCH more effective to pump the icewater into your chiller after you've used tap water to get the kettle down to about 120F.

 

[itsnotrequired]

Prechillers are quite ineffective due to stratification in that stagnant icewater bath. You can make them better by agitating the ice bath the whole time but it's MUCH more effective to pump the icewater into your chiller after you've used tap water to get the kettle down to about 120F.

i do 'bounce' the immersion chiller in the ice bath periodically to help with stratification. i throw in about 20 pounds of ice and by the end of the chill it is all melted so it must be doing something.

i don't do any whirlpool or recirculation so the more i think about it, the more i like the idea of passing the wort through the counterflow chiller first to bring it down to 100 or so and then running it through that stainless herms coil submerged in a bucket of ice to get it that last little bit. my thinking is that the temp difference between the hot wort and tap water is a greater differential than between warm wort and the tap water, resulting in more efficient use of the counterflow chiller. the only thing i would need to get is a couple compression fittings and a couple camlock fittings (you know anyone who sells those? ). i already have the coil, the hoses, the pumps, etc., seems like a relatively cheap experiment.

regarding stratification, i always felt this was a greater issue in hot applications. with an ice bath, the colder ice floats and as it melts, cooler water falls down through the warmer waters below. those warmer waters are rising so you get decent mixing. in hot applications, hot goes up and there is nothing to move that heat back down.

 

[Bobby_M]

regarding stratification, i always felt this was a greater issue in hot applications. with an ice bath, the colder ice floats and as it melts, cooler water falls down through the warmer waters below. those warmer waters are rising so you get decent mixing. in hot applications, hot goes up and there is nothing to move that heat back down.

You would think all stratified environments would have decent convection currents but none of them are fast enough to keep up with what we're trying to achieve. The water right next to the prechiller is going to be very close to the incoming tap water's temp and when you get an inch away it's near 32.

No matter what situation we find ourselves in where heat exchange is required, you HAVE to have good agitation. This is also why hot liquor tanks with HERMS coils need stirring or recirculation.

 

[20grit]

You could add salt to the water you're putting your pre-chiller in.
Do this the day before: get a non-insulative container, toss in some water, ice cubes, and salt. Place it in the freezer. The salt will lower the freezing temperature of the liquid allowing it to drop below 32° without solidifying.
When it comes time to chill your wort, put this water into a cooler and drop in the pre-chiller. This should help in lowering the temp a bit more.

Disclaimer: I've never tried this. But to my pre-caffeinated brain, it seems like it should work.

 

[itsnotrequired]

You would think all stratified environments would have decent convection currents but none of them are fast enough to keep up with what we're trying to achieve. The water right next to the prechiller is going to be very close to the incoming tap water's temp and when you get an inch away it's near 32.

No matter what situation we find ourselves in where heat exchange is required, you HAVE to have good agitation. This is also why hot liquor tanks with HERMS coils need stirring or recirculation.

on my last brew, i recirculated the ice bucket with my water pump while chilling. holy cow, the ice melted in about 15 minutes compared to the 40 or so minutes from the previous batch without recirc. lesson learned!