Wort Chiller not great

[TheWiggman]

That thread will go on in history Stu. For the mathematically inclined, I did a post which describes what happens in circular pipes used for cooling. There's lots of good advice, but just as much misleading advice in there too.

One issue with your idea OP is that you are effectively warming the ice bath with tap water, just as you are cooling the wort with the water that comes out of the ice bath. You are adding energy into the system by the way it's designed, whereas you want to take it away.
The ice bath + pond pump idea makes more sense because energy is not being added to the system, it is equalising across the system. However this isn't a good idea until the wort is cool, otherwise it will equalise very damn quickly.

• Don't bother with the ice bath until the wort has approached ambient temp, otherwise you're wasting energy warming up the ice when you start your cooling.
• THEN move to an ice bath and circulate between the two coils with the pond pump as suggested
• Move BOTH coils around as suggested above, or circulate liquid
• The cooling liquid needs to be colder than your target temp if you want it to drop. If the cooling liquid doesn't come out out very cool (i.e. 8-10°C for a lager) then you need more ice

 

[Adr_0]

Don't ever recirculate energy in a heat exchanger. You will end up warming the wort again until everything balances out. You can add ice again but your quantities of ice will approach what you need for an ice bath and you lose any benefit of actually using a heat 'exchanger'.

The only effective way to cool is single pass. Eliminate recirculation from your vocabularies and you will start winning.

If you are limited by the amount of ice you have, doing the first step with tap water is a good idea. If you have a few bags, why not use it all the way through and in 15min you're done.

 

[TheWiggman]

I'm a bit confused by your logic Adr_0. As you'd be well aware, almost all industrial heat exchanger unit use recirculating fluid. Cooler on one end, heat source on the other. Once acts to cool the liquid, the other acts to take heat away from the system by putting it into the liquid. How is this any different?
The energy isn't recirculated so to speak, it's transferred through each coil. Isn't OP using an ice bath and that's the whole point?

 

[Adr_0]

I'm a bit confused by your logic Adr_0. As you'd be well aware, almost all industrial heat exchanger unit use recirculating fluid. Cooler on one end, heat source on the other. Once acts to cool the liquid, the other acts to take heat away from the system by putting it into the liquid. How is this any different?
The energy isn't recirculated so to speak, it's transferred through each coil. Isn't OP using an ice bath and that's the whole point?

If the tap water gets cooled by an ice bath, then goes into a coil that cools the wort, that's awesome.

If it goes into an ice bath, then into a coil that cools the wort, then goes back into the ice bath, that's bad.

If the pump is just used to save stirring the ice bath, that's great...as long as no heat goes back into ice, then into the wort, then ice eetc . again bad news.

 

[TheWiggman]

If it goes into an ice bath, then into a coil that cools the wort, then goes back into the ice bath, that's bad.

Why? Assuming it's a closed system (i.e. tap's off)
Water cooled by ice bath > heated by wort > cooled again by ice bath then that's good. Ice bath temp will slowy rise and as a result the wort temp will drop. Pumping fresh 25°C water though the ice bath is worse than pumping wort that is approaching the ice bath temp. Which it will because their temps will converge as the system approaches equalibrium.

 

[Drew]

Well you need to add new water to the ice bath. Option 1 - tap water. Option 2 - recirculate. I would choose the colder of the two - which at this point of the procedure would be the recirculated water.

 

[Ducatiboy stu]

It seems a bit silly to be recirculating your chiller back into the ice bath at the beginning of the cycle

The water coming from the chiller is going to be very hot which will heat up your cooling water to the point of eventual equilibrium..

Better to remove the bulk of the heat with tap water then use the ice to get to final temps

 

[TheWiggman]

As per post #21

 

[Adr_0]

That thread will go on in history Stu. For the mathematically inclined, I did a post which describes what happens in circular pipes used for cooling. There's lots of good advice, but just as much misleading advice in there too.

One issue with your idea OP is that you are effectively warming the ice bath with tap water, just as you are cooling the wort with the water that comes out of the ice bath. Why is this an issue? You are lowering the temp of the cooling water, which provides more cooling power for your wort = a good thing. You are adding energy into the system by the way it's designed, whereas you want to take it away. That is 100% correct.
The ice bath + pond pump idea makes more sense because energy is not being added to the system, it is equalising across the system. You want to remove the heat though, not keep it within the system otherwise you end up with the ice bath scenario I described above, and you need about 10-15kg of ice to cool 20L of wort. However this isn't a good idea until the wort is cool, otherwise it will equalise very damn quickly. Fair enough if you are limited by ice. Otherwise you can save some water (spend money on ice instead) by using ice all the way through - trade off is up to the operator.

• Don't bother with the ice bath until the wort has approached ambient temp, otherwise you're wasting energy warming up the ice when you start your cooling.
• THEN move to an ice bath and circulate between the two coils with the pond pump as suggested This contradicts your 100% accurate statement above, i.e that you want to take energy away from the system. If you put it back into the ice bath, suddenly your ice water is 40-70°C and you are 'cooling' your hot wort with this, which will quickly equalise. To actually remove heat from the system you need to store this hot water somewhere else, allowing the 1-2°C ice water to keep flowing in. It means you lose that water, but being ice cold it means you use less of it.
• Move BOTH coils around as suggested above, or circulate liquid
• The cooling liquid needs to be colder than your target temp if you want it to drop. If the cooling liquid doesn't come out out very cool (i.e. 8-10°C for a lager) then you need more ice

 

[Ducatiboy stu]

You need one of these between the chiller output and ice bath to remove the heat from the chiller water

or you have a large tank of ice water

 

[TheWiggman]

Maybe you're misunderstanding me Adr_0, I said cool the wort down to ~30°C THEN use the ice bath. If the ice is 1-2°C and the wort is 30°C, then the net result will be somewhere in between.

Or what about an HDPE water container Stu? h34r:

 

[detunednath]

Thanks all. Great advice & much appreciated!

 

[detunednath]

Brewing a lager tomorrow.
My plan, after all the excellent advice I've received here, is as follows:

1) Tap water through wort chiller - running out into the pool.
2) pond pump immersed in bucket of ice - recirculating ice water through wort chiller, back to bucket of ice. Means I don't actually need the ice coil right? Any point in hooking it in line in the ice bucket anyway?

I'll let ya know how I go!

On the point of moving the chiller around though - won't this stir up trub? Recently wort was looking quite clear before I moved the coil around while chilling. I assume that's just a trade off? Move coil = more efficient chilling but with stirred up trub?

 

[HBHB]

On the point of moving the chiller around though - won't this stir up trub? Recently wort was looking quite clear before I moved the coil around while chilling. I assume that's just a trade off? Move coil = more efficient chilling but with stirred up trub?

Yep, and as it chills further the trub will settle quite fast.

 

[Sambrew]

Don't ever recirculate energy in a heat exchanger. You will end up warming the wort again until everything balances out. You can add ice again but your quantities of ice will approach what you need for an ice bath and you lose any benefit of actually using a heat 'exchanger'.

The only effective way to cool is single pass. Eliminate recirculation from your vocabularies and you will start winning.

If you are limited by the amount of ice you have, doing the first step with tap water is a good idea. If you have a few bags, why not use it all the way through and in 15min you're done.

I find that recirculating water from my 2500L rainwater tank through my chiller works just fine! Maybe it just comes down to thermal mass? If you have a big enough Ice bath for the input of recirculated heat to be insignificant you're winning, but a bucket aint gonna cut it. Replacing the Ice during recirculation increases your "cooling" capacity.

 

[Adr_0]

Brewing a lager tomorrow.
My plan, after all the excellent advice I've received here, is as follows:

1) Tap water through wort chiller - running out into the pool.
2) pond pump immersed in bucket of ice - recirculating ice water through wort chiller, back to bucket of ice. Means I don't actually need the ice coil right? Any point in hooking it in line in the ice bucket anyway?

I'll let ya know how I go!

On the point of moving the chiller around though - won't this stir up trub? Recently wort was looking quite clear before I moved the coil around while chilling. I assume that's just a trade off? Move coil = more efficient chilling but with stirred up trub?

Maybe you're misunderstanding me Adr_0, I said cool the wort down to ~30°C THEN use the ice bath. If the ice is 1-2°C and the wort is 30°C, then the net result will be somewhere in between.

Or what about an HDPE water container Stu? h34r:

Ok, fair enough.

Brewing a lager tomorrow.
My plan, after all the excellent advice I've received here, is as follows:

1) Tap water through wort chiller - running out into the pool.
2) pond pump immersed in bucket of ice - recirculating ice water through wort chiller, back to bucket of ice. Means I don't actually need the ice coil right? Any point in hooking it in line in the ice bucket anyway?

I'll let ya know how I go!

On the point of moving the chiller around though - won't this stir up trub? Recently wort was looking quite clear before I moved the coil around while chilling. I assume that's just a trade off? Move coil = more efficient chilling but with stirred up trub?

You still absolutely need the ice coil. Plastic hose doesn't conduct heat that well, and you need surface (copper tube) to remove the heat from the tap water before it goes into the wort.

How big is your batch size, 23L?

If you can leave the first coil in a bucket of water until you get your wort to 30-40°C, then chuck in a 4kg bag of ice yes you will get somewhere in the 10-15°C range.

 

[detunednath]

So to update on today's brewing: pretty successful!

Ended up dropping pond pump in the pool & recirculating that through immersion chiller til wort hit about 32°C. Seemed to stabilise there even though pool was at 27°. Guess that's the inefficiency of heat transfer through copper?

Then switched to recirculating ice water from a bucket. 2 bags of ice and about 100g of salt. Pond pump clogged with ice at first - took me 5 mins to realise what was going on. Then dropped wort to about 15°C.

Was happy with this so pitched. All up about an hour from boil to 15°. I'll Probably be faster without problems I now know to look out for.

Cheers for all the advice! Very much appreciated!

 

[GalBrew]

Salt is probably not going to be great for your coil long term.

 

[Adr_0]

What is your batch size Nath?

 

[mb-squared]

given your skills at bending copper tubing, you'd be able to whip one of these up in no time: http://www.thegatesofdawn.ca/wordpress/homebrewing/wort_chiller/

run your boiling hot wort through that and it will come out the other side at whatever temp your tap water is. then, if you want colder temps, continue your wort's journey through one of your current coils that you've immersed in an ice bath and your wort will come out the other side at whatever temp you want (depending on flow rate).

This is what I do (CFC followed by immersion coil in ice) and I'm able to turn 50+ litres of boiling wort into 50+ litres of icy cold wort in less than 10 minutes.