Flash Chiller to cool wort?

I am about to buy a heat exchanger and it got me thinking.
I have a pub style Maxi Cooler with two ins and outs.

Could I just run the beer out through the tap, through the flash chiller (down to 1-7 deg C) and then use my pump to put it back into the boil kettle, until I reach pitching temp?

Or, would I be killing something off by doing this?

Obviously, I'll be sanitising etc etc, but, would I do any adverse damage to the wort in terms of fermentability by doing this?

Thanks in advance.

DogAndDoris said:

I am about to buy a heat exchanger and it got me thinking.
I have a pub style Maxi Cooler with two ins and outs.

Could I just run the beer out through the tap, through the flash chiller (down to 1-7 deg C) and then use my pump to put it back into the boil kettle, until I reach pitching temp?

Or, would I be killing something off by doing this?

Obviously, I'll be sanitising etc etc, but, would I do any adverse damage to the wort in terms of fermentability by doing this?

Thanks in advance.

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I've been toying with the same idea myself but not tried it yet.

Well, as it was your idea first Brian ............ Haha.

DogAndDoris said:

Well, as it was your idea first Brian ............ Haha.

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I'm overseas working for the next three weeks so I'll be giving it a try when I get back. I'll report back.

Problem is the ice bank will be nowhere near large enough to cool a 23L batch, it would be good to get the last 10C ish down quickly but need sto be sterilised.

simon12 said:

Problem is the ice bank will be nowhere near large enough to cool a 23L batch, it would be good to get the last 10C ish down quickly but need sto be sterilised.

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The other option I was thinking about was to run the maxi cooler through a cooling coil in a dustbin of water, when it comes to time to chill the wort connect my water hose to the dustbin cooling coil and run that through the wort cooling coil.

BarnBrian said:

The other option I was thinking about was to run the maxi cooler through a cooling coil in a dustbin of water, when it comes to time to chill the wort connect my water hose to the dustbin cooling coil and run that through the wort cooling coil.

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I think the problem would still be at some stage 30-40C guesstimate everything would get to the same temp and cooling would stop totally or at least go the level the maxi can chill which is very very slow. It could work if you could leave the maxi chilling the dustbin water for hours and the dustbin had 5-10 times the water of the wort you want to cool all chilled to 2-3C. But the problem is still as you are chilling the chilling is getting less efficient all the time when you want it most efficient at the end. So like I said before using an immersion chiller in the normal way and using the maxi to chill the last 10Cish would work much better.

I use something like a Maxi to cool my wort. But it's not as straightforward as you might hope.

Reading the instruction manual for the cooler (that makes me weird for a start) it instructs you NOT to run liquid hotter than 40C through the coils.

That also makes sanitizing a pain, you can't recirculate near boiling wort through it. So you need a way to pump cleaner/sanitizer through the coils followed by rinse water.

I am using a shelf cooler because the counter-flow cooler had issues, but I still use the counter-flow to get the temperature down to 30C in a jiffy (big MarchMay pump at full-bore, 15mm, the issue with that CF cooler is getting down lower when the tap water is at 18C). The warm wort then goes through the shelf cooler (both coils, they are linked in series). At this point you lose control of the temperature: It starts coming out at about 12C, but as the ice wall melts it steadily rises to 27-28C (45L batch). The agitator on the cooler must be running at this time.

I've a bit of tuning with the setup but currently I get 45L of wort to 22-23C within the hour. The shelf-cooler doesn't stop its work there, it goes on supplying cold water (python lines) to coiling coils on the fermenter (ITC-308 controlled).

simon12 said:

I think the problem would still be at some stage 30-40C guesstimate everything would get to the same temp and cooling would stop totally or at least go the level the maxi can chill which is very very slow. It could work if you could leave the maxi chilling the dustbin water for hours and the dustbin had 5-10 times the water of the wort you want to cool all chilled to 2-3C. But the problem is still as you are chilling the chilling is getting less efficient all the time when you want it most efficient at the end. So like I said before using an immersion chiller in the normal way and using the maxi to chill the last 10Cish would work much better.

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What I was suggesting was chilling the bin of water down for two or three hours while brewing. Would then run mains water through the coil in the bin, thus pre-chilling it before it goes through my wort cooling coil.

OK, that makes more sense. Only thing is like I said the cooling will still get worse as it goes and you may find it works better only using it for the second half of chilling but you can experiment with that to find out.

simon12 said:

OK, that makes more sense. Only thing is like I said the cooling will still get worse as it goes and you may find it works better only using it for the second half of chilling but you can experiment with that to find out.

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I don't see that the rate of chilling will deteriorate by much. At the end of the day it's going to be a lot faster than running the water straight from the tap as I'm doing at present

It may or may not like I say try it and see. I was just saying the longer you are using the bank of cold water the hotter it will get until you try it you won't know if the cooling water is still 1C hotter than the start or if halfway through the water is no cooler than the mains water.

Let add a tad bit here because I see lots of people doing it wrong or at least what the manufacturers of plate chillers and counter flow chilers say. Ten minutes before flame out, run the boiling wort through your chiller. This will sterilize it. On flameout, turn on your water and drop the wort temp down to 70 degrees or so. Anything below 80 is fine. Once there, you can just pump your wort through the chiller into the FV. Control the flow of the water as well as the flow of the wort so it is at target temperature coming out of the chiller. My plate chiller will get boiling wort down to 70 in less than 2 minutes. Then straight into the FV. The wort coming out on mine is about 20 c.

Sorry, addon now to the OP. Why not go another direction and pump water through your flash cooler and keep recirculating it? Wouldn't that get REAL cold water going through your coil?

I have the maxicool 110 and it won't chill hot wort very quickly. I use the ss bme and use the 110 to maintain the fermentation temp. I did my 1st ag brew last week and used a counter chiller to get the temp down to 30deg an d then put into the fv and used the 110 to drop to pitching temp. It took quite a while so agree that the maxi cool is not built to facilitate large temp drops. Also the coil will not take high temps and will be a pig to clean and sanitise.

BarnBrian said:

I don't see that the rate of chilling will deteriorate by much. At the end of the day it's going to be a lot faster than running the water straight from the tap as I'm doing at present

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You "don't see that", but I do! I'm doing it for real and the rate of chilling significantly deteriorates as time progresses. And I'm still using the CFC to get the wort below 30C before it goes to the chiller.

The system is far from perfect but it is a lot faster than using tap water and the CFC alone - during Summer that would use a tonne of water to cool 45L to 20C. Some fiddling with flow through the CFC (so it is cooling to 25C say) should help me attain the target 18-20C output into the fermenter.

What I need is a data-logger to get a true readout of what the temperature is doing. Hum... I'll work on that.

JapanBrew said:

Let add a tad bit here because I see lots of people doing it wrong or at least what the manufacturers of plate chillers and counter flow chilers say. Ten minutes before flame out, run the boiling wort through your chiller. This will sterilize it. On flameout, turn on your water and drop the wort temp down to 70 degrees or so. Anything below 80 is fine. Once there, you can just pump your wort through the chiller into the FV. Control the flow of the water as well as the flow of the wort so it is at target temperature coming out of the chiller. My plate chiller will get boiling wort down to 70 in less than 2 minutes. Then straight into the FV. The wort coming out on mine is about 20 c.

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Yeap, that's pretty much what I do. Recirculate through the CFC to get the temperature in the boiler to 70-80C (any steep hops go in now) then off to the chiller and fermenter. But I still keep the CFC inline so the chiller only sees wort at about 30C.

As for your next post: Don't know much physics, but what I do know is you can't cheat at thermodynamics. The more convoluted the technique the more likely you introduce inefficiencies and the further from your aim you get. But I did like earlier suggestions to use a chiller to pre-create a large reservoir of cold water for the CFC rather than use tap water. But I haven't the room for that.

I think there is a little confusion by a couple on what the flash chiller is and what I was going to do. I'm going to put the wort straight into the chiller, not use it to chill some water to run through the coil / bin etc (that was a secondary option), as this would still waste some of the energy and result in wasting water.

I can get water from 60deg C down to the correct chilled temperature (4 or 5 degC) by just putting it straight through the flash chiller and it doesn't fluctuate (so agree with this as a good secondary measure , as the chiller is plugged in, so keeps it to that temperature). I tried this after I collected the heated water from my last brew (which I used to wash and clean everything and not just waste the water). I put 50 ltrs through and it was constant 4-5degC.

My question is, would it do anything to my wort which is running through the chiller, as it will be going from boil temperature down to 4 or 5 degC, then added back to the boil kettle to chill it down that way.

The one I used (although I do have a couple) was the Maxi 110.

Simon - You have to sterilise it before you run beer through it to serve anyway, so it will be clean and sterilised with blue line cleaner / starsan etc. These chillers aren't slow, they're flash chillers, you could run a series of 11 gallon barrels through them and the temperature won't fluctuate. I know I have a higher starting temperature, and I could use a couple of them in series.

Secondary would be to run water through it to save on waste and pump that through either a counter flow chiller or a cooling coil etc and whirlpool it, but I just wanted to use the chiller.

I'll tell you what, I'll just try it.

DogAndDoris said:

... I'll tell you what, I'll just try it.

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Good, keep us posted how you get on.

But you did ask a question to get other people's experience. And you've been given it. Choosing to ignore it is your prerogative. I'm concerned you have a distorted view of what a chiller can do - the cold water bath is something like 4-5 litres, it has an "ice-wall" (acting as a cold reservoir) of probably less than a litre, takes 1/2 - 1 hour to build up that ice (or more?), and you want it to cool 25-50L of near-boiling wort down to 4-5C with it.

Even big pubs have mammoth coolers to get the beer they serve down to 4-5C, from 10-15C. Shelf-coolers (like Maxi 310s) are for diddy little pubs.

Good luck.

My idea wasn't so much as cooling wort per say. Going opposite in that you're recirculating a fixed amount of liquid, let's just call it what I'm suggesting, a glycol chiller. You're turning your flash chiller into a glycol chiller. The reason for this is the same as a coil chiller. You want your wort to come into as little contact to un sterilized items as you can. It seems like you're trying to go some kind of economic way around a problem but the goal isn't to save water, it's to produce good beer. As for being economical I save all my chill water. I use it for cleaning, watering the garden and on heavy brew days, it's back in the HLT for a round of brewing. You can keep run off water for a week or so. Remember we're boiling the hay day of it.