# Glycol For Plate Chiller



## PistolPatch (19/7/09)

I was wondering if anyone has made any progress in using a cube of glycol solution to run through their plate chiller.

As I often simultaneously do two double ale batches or two single lager batches, I am considering cooling my batches initially with my immersion chiller and then using a plate chiller to get them to a few degrees below pitching.

I have a freezer compartment in one of my fridges that holds a cube and I imagine would get down to about minus 20 degrees. So...

1. Has anyone tried this?
2. What percentage glycol solution do you use?
3. Where do you buy glycol and what sort should you use? (I hear polypropylene glycol is slower to react with copper then ethylene glycol?)
4. How much does it actually chill?
5. What chiller did you use?

Hope someone has tried this or that at least someone can help with one or two of the questions.

Thanks a lot :icon_cheers: 
Pat


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## seravitae (19/7/09)

I did the math for this exact outcome (someone using a freezer with water/glycol from freezer to chill wort) a little while back - search my name and see if you can find it.


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## PistolPatch (19/7/09)

Tracked your post down here thank you sera.

My head swivelled a bit at the maths but I think I got it eventually 

I understand your point on the energy required to melt ice but in my situation, the melting of the ice will create a logistical nightmare and be time-consuming.

Just realised I can actually get 2 cubes in my freezer section so I reckon I'll go 2 cubes of 40% propylene glycol and that should get me there after chilling the bulk with my immersion chiller.

I'll try anything once!

Now where to get the glycol easily???? Auto shop do the job do you think?

Thanks sera :icon_cheers:


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## Sully (19/7/09)

The Automotive stuff will do the job - HOWEVER risky if you get cross contamination - Automotive Coolant + Consumption = DEATH (almost). 

CB sell a food grade Glycol or check Andales website and see if there is one local to you, I doubt it will be able to be posted. 

HTH

Cheers

EDIT: link to CB glycol > HERE


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## jjeffrey (20/7/09)

Ethanol brine solutions (modern household metho is ethanol) are commonly used for heat transfer applications in the food industry because of the potential contamination issue (instead of glycol). A solution of about 40% by volume will allow the solution to remain as a liquid at -20deg C. In rough terms, you will need about 2 cubes (40L) of ethanol brine at -20deg to drop 40L of wort from 40degC to 20degC.

The heat capacity of most brine solutions (be they alcohol or glycol based) are generally about 0.6-0.8 times that of water. To simplify the maths, what this means is that if you use the same amount of brine (ethanol, glycol, whatever) as you have wort, you will need about 50% more temperature change in the brine than you get in the wort. Eg- cool you wort from 40 to 20 (20degrees difference), heat your volume of brine up from -20 to 10 (30 degrees difference).

Personally I used a couple of trays of ice, and use a little plastic kitchen tidy bin as an ice holding tank. I do this because you need a smaller volume of ice than what you would need for a brine (because of the energy of freezing). Chuck in the slabs of ice, top up with water, then pump the "ice water" from the bin through the HE and back into the bin. The greater the temperature of wort you need to drop, the more ice you make. If you don't have enough ice, you can always get bags from the servo. I generally drop 60L of wort from 40deg to 15deg with the equivalent of 3 bags of ice.

jj.


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## seravitae (20/7/09)

pete, no worries, im sure you'll sort out what's best for you.



I'm intrigued though, why do you say melting ice will be a logistical nightmare?

jjerffrey - good points. Although, bear in mind that the temperature of the coolant to the temperature of the wort will determine the heat flux. Calculating things in such theory as you've done might work by chance, but generally speaking, the colder the chiller, the better, as you can have a much faster flow rate due to higher heat flux. That's why wort cools quickly the first 10-20C, but then slows down as its temperature starts to approach the temperature of your chiller/water..

Hot things cool down quicker, Colder things heat up quicker, if you get what i mean. 

I am keen to see the results of this project.\

P.S Ice is infintely cheaper than food grade glycol, it may be cost prohibitive in your case, with two cubes.


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## jjeffrey (20/7/09)

Patch, if you do use a sub-zero coolant system (glycol, ethanol, whatever), make sure you start the wort running before you turn your coolant on, otherwise you will freeze it up (another reason why I prefer ice water)



sera said:


> jjerffrey - good points. Although, bear in mind that the temperature of the coolant to the temperature of the wort will determine the heat flux. Calculating things in such theory as you've done might work by chance, but generally speaking, the colder the chiller, the better, as you can have a much faster flow rate due to higher heat flux. That's why wort cools quickly the first 10-20C, but then slows down as its temperature starts to approach the temperature of your chiller/water..
> 
> Hot things cool down quicker, Colder things heat up quicker, if you get what i mean.



sera, that's true, which is why I outlined figures that would give a minimum differential of 10 degrees between the wort and the coolant. It's not chance, it's based on my professional experience.

For continuous operations (say the wort was draining from the kettle to the fermenter via a plate heat exchanger), we normally work on an approach temperature (that is, diff. bw hot and cold side of HE) of at least 20 degrees when we size plate heat exchangers. With a fixed brine volume (a recirculated brine loop), what happens is the 1st lot of wort is bloody cold, and then the wort temp coming out of the HE increases as the coolant volume absorbs the energy. The temperature of the last wort may actually be higher than what you want, but when it mixes in with the rest of the chilled volume, the overall temp will be where you want it. Generally, you see a fixed temperature differential between the hot and cold side- it's not time dependant.

Using an immersion coil rather than a continuous process in a plate HE (batch operation), my calcs show that you can actually cool down 40L of wort from 40 to 20degrees with only 24L of brine that has an initial temp of -20. As you point out thou, this would take a bloody long time (hours, depending on the heat exchanger). 40L of brine will alow the same cooling to occur without reducing the approach temperature below 10 degrees C, and hence speed up the process considerably. With most heat exchangers available to the homebrewer, we are talking about less than 40 minutes. My kit will acheive it in about 10 minutes using this rule of thumb, but I have a very large exchanger. We have found that a target final temperature difference of 10degrees is a good balance with batch operations. More than this and the coolant requirements become very large. Less than this and the time requirements become considerable.  

jj.


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## seravitae (20/7/09)

Yep, i dig what you're saying.  Seeing as I use/planned an actively cooled system, my chiller loop provides a constant temp source (theoretically infinitely large chiller volume) so flow rate directly determines output temperature, but yes, i see now in a passively cooled system, as the brine temp goes up, the heat flux goes down, but successive mixing of the incoming wort to the wort already passed through the chamber has a gradient that balances the energy in both the wort and the brine. So yeah, i guess in this case it's balanceable. 



mm, food for thought. (now where's my dinner!)


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## Thirsty Boy (20/7/09)

I'll re0inforce what jjeffry says about the chiller freezing. You really really will need to watch that. Counter flow plate chillers freeze like a bastard when you are using a sub-zero coolant. It makes a spectacular mess when you are talking about pumped systems and plate and frame chillers - in a gravity system and a brazed chiller like HB people use... ti would just stick solid and give you a pain in the bum.

My vote would be for using an immersion chiller in a bucket of ice water - to pre-chill the water for your plate chiller. You should (if your plate chiller performs like my MM chillout) be able to get your wort to within around 10C of your chiller water temp and not be going too slowly -- so if you pre chill you tap water down to 2-3C via a pre-chiller. Thats lager pitching temps straight out of the chiller. First pass.

Glycol (or an ethanol/brine) will of course work - just not as well as an equivalent lump of ice and some water would, and it presents problems with freezing, contamination and finding a pump thats happy with -20C liquid.

If the spirit of adventure drives you -- by all means play with glycol, but if you just want to get the job done. Then I reckon you are better off with chilled water and ice to keep it that way.


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## PistolPatch (20/7/09)

First the bad news. I just arrived home with 10lts of glycol to find all the above posts. I didn't realise all this good advice would come in today. I must admit, as I was buying it, the phrase, "taking one for the team," sprang to mind - again 

Maybe I'll go and spend a couple of grand on a flooded font or something  

I might have an idea though! (See at the end. This is where I will bore you to tears.)

*Sully:* Thanks mate. I had no idea there was a food grade one. I am now a proud owner - lol - purchased it from Hoshizaki Lancer in Canning Vale.

*jjeffrey:* Thanks for all your detail jj. That is really clear. (There is a little bit at the end though I might have to read a few times before it sinks in fully.) Didn't even think of the bloody freezing up of the plate chiller. My goodness! Thanks for your tip because freezing the chiller would have been the first thing I managed to do for sure! I'll explain the logic of my wanting to avoid ice below in my reply to sera. Your calcs have given me some hope though so all is not lost.

*sera:* Glad to hear you are keen to hear the results. So am I!!! Thanks once again for your other post too on the energy of melting ice. The logisitcs of why I wanted to avoid ice for the plate chiller (ordered and on its way - more lol) are, for a start, I'd need a whole lot of relatively small containers for it and would have to fill them each time and spill water all over the carpet that my brewing fridges sit on in my apartment. The idea of just being able to use the 2 cubes (which fit perfectly in the freezer compartment of my fermenting fridge) take them out and gravity feed them through the plate chiller back into another cube, is fairly simple and I thought would save a bit of water too. In an apartment, cleaning etc is always a nightmare. Cube in, cube out, cube back in sounded great to me!

*ThirstyBoy:* I have the MashMaster Chillout MkIII on its way! I am just going to gravity feed it probably by giving it a hoist up on my BIAB pulley so it is quite high. I have never used a plate chiller before and am worried the viscosity of the gllycol mix might be a bit thick. Your post gave me an idea though if it all doesn't work as I have a pre-chiller - see Summer Plan below. Thanks mate! (I am really trying to think ahead here to the summer when our tap water can get up to 26 degrees, sometimes a tad more believe it or not.)

[The following is me thinking out loud and pretty boring - even to me! You'll see I have given up so read at your own peril! I have also come to a fairly obvious conclusion fairly quickly for the likes of me!]

*The Two Plans... Both are a Guess* 

OK so I have a pre-chiller, an immersion chiller and a plate chiller at my disposal. Quite ridiculous really but I hate waiting to pitch. I also have a pond pump but it has low head and I don't want to go through the hastle of setting it up. I have 2 plans, one for this weekend when tap water is 18 degrees and one for the summer when tap water can reach 28 degrees. 

I will, of course, have 2 x 23 litre cubes of glycol which I assume I can get to -18 degrees in my freezer though I don't have a thermometer that goes this low. (And let's pray I bought enough glycol so it doesn't freeze. I'll throw it in the freezer tonight.)

7 degrees Celsius = the goal for lager pitching and then I'll let it rise up to 10 degrees because hopefully I can!
19 degrees Celsius = the goal for ale pitching.

Finally, I want to waste as least water as possible but then again, I want to balance this with considerable laziness and some speed. I want to use all the cooling energy I have available conveniently.

*For this Weekend - Tap Water at 18 Degrees*

Due to the charity event, Australia's Biggest Brew Day I am doing 2 single batches on Saturday (one lager and one ale) and on Sunday I am doing 2 double batches (also a lager and an ale). So this weekend should be interesting at least. Each single batch = 23lts into fermenter.

Saturday - Single Batch day - Assume same boil end time so I will chill the Lager and the Ale simultaneously.

Step 1- Whirlpool and then gently add sterilised chillers. (Usually add chiller 15 minutes before boil end but I will, for the first time, have taps on my kettles and will need to whirlpool. Also have a little pre-filter now for the plate chiller). So, put main (big) immersion chiller in lager and pre-chiller (small) in ale. Wait until temperature drop becomes slow in the lager, probably around 25 minutes max if I agitate the chillers from time to time and even with slow garden hose flow. I assume the temperature of the lager at this stage will be about 30 degrees and the ale is any man's guess - maybe 50 degrees.

Step 2: For convenience, leave both chillers in at slow garden hose flow rate. Set up plate chiller. Run 1 cube of glycol through and hope for the best!

*End of Plan for Now*

My head is spinning and I think that is as far as I can sensibly plan until I actually do the first run on Saturday.

My confidence levels are fairly low but then again my expectations are high. Maybe it will turn out well for ales? Who knows?

Thank you all for your help and your interest. I will keep you posted of course and please feel free to change my initial plan above.

:icon_cheers: 
Pat


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## PistolPatch (20/7/09)

Can see Saturday becoming a nightmare - lol!

Does anyone know where I can buy an inline thermometer to put at the back end of the plate chiller?

Might as well spend more money


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## Thirsty Boy (21/7/09)

Nothing to do with chilling effectiveness - but I would chill with the immersion chillers first, then whirlpool after you take em out -- or whirlpool with them in there. I'm not sure of the size (diameter) of your chillers, but sort of normal ones you should be able to get a decently effective whirlpool going with the chillers still in there, and it will actually help the chilling process along. Then there is no mucking up your trub cone trying to stick a chiller in there all gentle like.

*Ice anybody* .. if you use ice as a way to pre-chill your water before it gets to the plate chiller, it can be relatively mess free. A 5kg bag of ice does a respectable job of chilling a whole batch down - so if you are just chilling 28C water down to 3-4C water, you are going to need a whole lot less. Say 3 icecream tubs ... hang on, thats 6L anyway!! Surely you can fill and freeze 3 ice cream tubs without making a mess.

So - here is an alternate plan for you. One that I think might be easier (no pumps required). I think you should still do your plan/s .. but maybe try this one down the track too 

- Knock the guts out of the temperature in the way you decribed with your immersion chillers
- take the chillers out and whirlpool
- while the whirlpool is happening/resting, put both your chillers into a bucket of water (preferably one you have had in the fridge overnight). Run your water supply through them both in series, then to your plate chiller.
- plonk an ice cream tub sized block of ice into the bucket and jiggle it round till the water gets cold
- cool your wort via the plate chiller and water that has run through both pre-chilling coils
- jiggle the pre-chilling coils around to maintain effectiveness - replace ice block when its nearly gone

OR - skip the part where you initially cool the wort with the immersion chillers. With a chillout mkII and 12 tapwater, I am able to get my wort straight from the kettle to about 21-22C in one pass. If that tap water were 3-4C (as in exiting your pre-chillers) you would have to be getting your wort down to less than 15 ... surely thats close enough??

Or who knows -- your glycol thing might work perfectly and be no trouble at all. Just tossin' some options at you PP ole buddy.

TB

PS - inline thermometer. See this guy's site and this solution. Same could be done with a bit of half inch copper pipe and some hose clamps.


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## PistolPatch (21/7/09)

Thanks Dan. Great to see some real-life figures. More confidence!

I wonder if those in line thermometer guys can deliver by Saturday 

In another year, you will see that PP is a no-chill fanatic! I better get it all right first though eh?

Spot and thanks,
Pat


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## Screwtop (21/7/09)

PistolPatch said:


> Thanks Dan. Great to see some real-life figures. More confidence!
> 
> I wonder if those in line thermometer guys can deliver by Saturday
> 
> ...




Pat, if you've got a MM MashMate or even a Fridgemate, grab yourself a MM 1/2" SS probe. I have one plumbed into the outlet of my plate chiller, when time comes for chilling the MashMate is no longer required for monitoring mash temp so I unplug the probe and swap to the one in the probe in the chiller outlet to monitor the wort temp exiting the chiller. Run tap water through the chiller and while recirculating back to the kettle for whirlpool. After 15 min whirlpooling wind back the flow of wort and the temp should drop to 20 - 30. Swap over then to a bin full of ice water with a submersible/bilge pump and recirc the ice water, with the flow of wort slowed down you will have sub 20 wort in no time flat. adjuct the flow rate to obtain pitching temp. Slow wort flow is useful as you can pitch your yeast into the bottom of the fermenter and dribble in the wort at the top of the fermenter, takes about 20 min to fill the fermenter with good aerated wort. I used to recirc from the swimming pool at the last address, here I recirc from the rainwater tank, minimal water wastage.

Screwy


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## kirem (21/7/09)

I am building up a recirculating water system for a plate chiller.

It is an esky that slides into the bottom of my brewery frame and has an aquarium pump that pumps water from the esky through the plate chiller, through a peltier effect water cooler sump (taken from an office water cooler) back into the otherside of the esky.

I purchased another march pump for the kettle so I can recirculate the kettle on its self through the chiller.

The aquarium pump and water cooler will be controlled by a surplus PID temperature controller running in on/off mode.

I have used a similar system in the past, without recirculating on its self and it gave me enough confidence to develop this idea further.

I freeze water in those 2L ice cream containers and just add those to tap temperature water in the esky.

My kettle has fittings to generate a whirlpool.

I will find out how it all works this week.

I did think about glycol, but the pros/cons compared to iced water (already discussed in this thread) gave it the tumbs down for me.


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## PistolPatch (21/7/09)

Thanks Screwy! I might have to give you a call re how you plumbed the probe in. Sounds flash!

Seeing as I had way too many beers last night, I never got around to mixing up my glycol  

Was just about to do it and then remembered from my pub days that the glycol mixes were always slowly agitated.

If I do my glycol mix without having any sort of movement in it, is it just going to freeze up on me or should I go ahead?


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## Screwtop (21/7/09)

Like so Pat, I cut the leads on the probes leaving a short flying lead with polarised line connectors sealed up at the cable entry with silicone. The long lead from the MashMate is disconnected from the probe in the HERMS HE wort out after mashing to the probe on the chiller wort out. 




Screwy


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## Thirsty Boy (21/7/09)

ooooh - nice!!


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## PistolPatch (21/7/09)

Tis eh?

Thanks Screwy. I think for this weekend, I'll drill a hole in my silicone hose and shove a probe in there. That'll do it.

Instead of drinking tonight I am going to mix up my glycol and cross my fingers. It's been a very expensive brewing week this week


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## jjeffrey (21/7/09)

kirem said:


> I am building up a recirculating water system for a plate chiller.
> 
> It is an esky that slides into the bottom of my brewery frame and has an aquarium pump that pumps water from the esky through the plate chiller, through a peltier effect water cooler sump (taken from an office water cooler) back into the otherside of the esky.
> 
> ...



very similar to my setup, although I found the peltier water cooler bizo to be somewhat ineffective for chilling- just doesn't have the capacity to remove so much heat (good for temp control in the fermenter tho). I do a cool with tap water through the exchanger 1st, then rig up the ice-water circuit when the wort is somewhere b/w 40-50deg. You'll find you chew through the ice otherwise. for 40L, i'll use about 2 bags of ice.

I went from a system that TB described (immersion coil in kettle, then run wort through another copper coil in an icebath on the way to fermenter) to the one you have just described. I now use only 30% of the water, and can chill down to 10degrees- plus the whirlpool action rocks (and no coil in the way to make eddies). There's something about watching cold-break forming before your eyes and forming a big jelly mass in the centre of the kettle that's kind of like poetry. I found that I still needed to stir to start the whirlpool tho (my little diaphram pump is too slow). Wasn't a fan of the plate chillers using this method- I found it collected break/hops and gummed up readily. You may want to consider a strainer or pre-filter. I use a double pipe heat exchanger for this reason.

No-chill guys, can't you see the all fun you miss out on?


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## PistolPatch (28/7/09)

jjeffrey said:


> No-chill guys, can't you see the all fun you miss out on?



FOR SALE - 46LTS OF 40% GLYCOL!
Must sell - Going Overseas :unsure: 

Oh man, what a debacle that weekend was! Check out my link at the end of this post for the simple way I used to do things!

Here's the glycol results....

*Single Batches*

Put small immersion chiller in Lager kettle and this fed my large immersion chiller in the ale kettle. Lager reached 26 and ale 32 degrees as the small chiller had the coldest water entering it. (Still surprised at the difference as the small chiller is tiny and the large one is huge.)

I then took the chillers out and whirpooled.

I then ran the ale through the plate chiller and hit about 18. I then put the small chiller in a bucket and filled that with about 20lts of the glycol. This fed the plate chiller. And the end result was, wait for it, 13 degrees - a whole 3 degrees difference  

*Double Batches*

On the Sunday I had helpers and we let the kettles cool to about 80 degrees and then whirlpooled. We then let them sit for about another 3/4 hr as we needed a rest. The kettles had cooled to about 60 degrees.

We then sterilised and gently added the large immersion chiller to the lager kettle. This was fed by the outlet from the plate chiller. The ale was dropped from the 60 degrees through the plate chiller into the fermenters and we reached about 20 degrees though the temp changed up and down due to some major plumbing problems - lol!

Once the ale was done, we dragged the mini immersion chiller into play and put this in a bucket filled with 20lts of glycol. This fed the plate chiller and PC outlet fed the large immersion chiller still sitting in the lager kettle.

I forgot to measure the temp of the lager before we dropped it through the plate chiller but the long and short of it was we only got about 17 degrees.

*Summary - Don't Do What I Did!* 

On all brews, only a 3 degree difference. The lowest temp we saw was 13 degrees right at the beginning of transfer.

I wish I had seen sera and jj's posts before buying that bloody glycol because...

Anything apart from ice is a waste of time and energy.

Thanks to everyone for their help here. I am now going to go and think of a way that I can use ice conveniently in my apartment.*

Thanks again,
Pat

* It's funny looking back. Check out the solution I was using almost 3 years ago for lagers in my Gold Coast apartment where I was really stuck for space. This worked a treat. Definiteley time for me to stop and have a think before I reach into my wallet again.

Edit: Just had a look at the linked post and what is not obvious is that I used to have my fermenter in that esky sitting above the fridge. The pump pumped the chilled water up to the fermenter sitting inside the esky.Looking at the photo in this post will make it clearer.


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## jjeffrey (28/7/09)

Bugger.

Coolant systems CAN be useful, but a small homebrew scale system will just not have the energy absorption capacity required for chilling.

They are good for controlling fermentation temp during summer though (or in QLD most of the year- here in vic you need the belt heater 4-6 months of the year). Only low level heat transfer is required for this. You can use a temp controller and a little pump from dick smiths or jaycar to push the coolant through an immersion coil, which sits in your fermenter. You can keep the coolant in your freezer during the process, use a peltier device, or pump from an esky and change the coolant on a regular basis (last option sucks balls on account of effort required).

EthGycol don't go off. Your car will never overheat again :icon_cheers:


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## PistolPatch (28/7/09)

jjeffrey said:


> Bugger.
> 
> EthGycol don't go off. Your car will never overheat again :icon_cheers:



LOL!


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## PistolPatch (28/7/09)

Actually jj, I am just thinking about the way I used to do it as linked above. In those days, I only had 10lts of iced water to pump around the mini immersion chiller inside the fermenter. Now I have 46lts of glycol  

I need an extra fridge here but I am not game to have 4 fridges in my apartment :huh: 

I think I will go back to basics and maybe set up a "cool compartment" to fit 2 fermenters that will imitate the esky set-up I linked above. I had no problems with copper in my fermenter so what''s the worry? This will get the freezer part of my fridge/freezer doing something useful.

Maybe this debacle could turn into something great?

Spot!
Pat

P.S. I wonder if my pond pump can handle pumping -15 degree glycol?


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## Online Brewing Supplies (28/7/09)

PistolPatch said:


> Actually jj, I am just thinking about the way I used to do it as linked above. In those days, I only had 10lts of iced water to pump around the mini immersion chiller inside the fermenter. Now I have 46lts of glycol
> 
> I need an extra fridge here but I am not game to have 4 fridges in my apartment :huh:
> 
> ...


Copper in fermenters is no good.Off to study more beer judging info!
GB


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## PistolPatch (28/7/09)

How much, "no good?"

Worse than using 65 degree rated hose to no chill? (That'll upset someone - naughty me! :lol

Seriously though, if they used to boil the wort in copper kettles, is having it in the fermenter worse?

If so, what do you suggest as an alternative as my mind is already racing back to adopt my old mini-immersion chiller days to my current set-up.

What pumps (small and cheap) will handle glycol?


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## riverside (24/8/09)

PistolPatch said:


> Thanks Screwy! I might have to give you a call re how you plumbed the probe in. Sounds flash!
> 
> Seeing as I had way too many beers last night, I never got around to mixing up my glycol
> 
> ...


Spot on PistolPatch, you must run a agi pump with a glycol mix. Next time try Actrols in Oconner for your glycol.


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## jjeffrey (24/8/09)

PistolPatch said:


> Seriously though, if they used to boil the wort in copper kettles, is having it in the fermenter worse?
> 
> If so, what do you suggest as an alternative as my mind is already racing back to adopt my old mini-immersion chiller days to my current set-up.
> 
> What pumps (small and cheap) will handle glycol?



Regarding pumps, the issue with the low temp is that any rubber seals will go really hard at the low temperature. This isn't a problem for static seals, but any seals on moving parts will wear pretty quick. The best option is a magnetic drive pump, which will have an impeller contained in the pump casing (no shaft seals). Most aquarium pumps are mag drive (so you are probably good to go), as are March pumps. If your pump DOES have seals on moving parts, I'd give it a go anyway and replace the seals when they wear out (they are generally just o-rings, so not a big expense).

Regarding copper coils, the issue here is that a small amount of dissolved copper in the wort is good, but a large amount is toxic to the yeast. In the kettle, you've a short exposure time and a pH of around 5. The result is a relatively small (non-toxic) amount of copper that gets dissolved into the wort. In the fermenter, you have an exposure time of around 300-400 times more than in the boil, and the pH is around 4 so you get heaps more copper being dissolved. You will get attenuation problems if you have copper in your fermenter.

So what do you use instead of copper? The important thing to consider in fermentation vessel coil design is that the heat transfer required is sweet FA. This means that you don't really need to make the coil out of a material that is a good heat conductor. I use 1/4" SS tube coz I can get it easy and it's easy to bend, but plastic AG pipe is also fine. Another easy one is clear PU tube, or pnumatic tube for those that can pinch it from work. Bendy tube is way easier than stiff tube. Make sure there are NO joints inside the fermenter- the coil needs to be continuous so that if a joint leaks you don't pump coolant into the brew. Start with a length of around 5m, and if you don't get enough cooling, put a longer length in. Also, coiling coils need to be at the top of your brew (hot wort floats on cold wort). The way I do mine is I put a couple of cable glands in the lid of the fermenter (you will need a rubber seal, o-ring or silicone on the gland bulk-head). Cable tie your coil together and suspend it from the lid via the tube tails through the cable glands. You can easily adjust the height by lossening the boss nuts on the cable glands, pulling/pushing the tube tails and tightening up again.

jj.


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