# Mash Tun issues



## RobinW (28/10/17)

I'm building up a 3V system but have some issues with the mash tun. Now this is an old coleman cooler, I mean about 30 years old. The lids a bit bent but I'm working on fixing that and a strap fixes it in the short term.

I'm getting a 3degree+ drop over an hour even with pre heating it a lot.

I suspect it's too big, 40L, and I'm dropping in 15L of water. I think there's too much head space. I'd like to try a hi density foam plug. The bottom is smaller than the top so in theory I can cut a plug to go half way down.

Any clues on where to get this foam. I got a clark rubber near by but the web site is useless for searching.


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## Hermies (28/10/17)

Big Green shed . I just cut a peice of styrofoam to shape and covered it in cloth tape hardly lost any temp over the hour mash .


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## RobinW (28/10/17)

.PolyStyrene. That'd be a lot cheaper. What's this cloth tape you mention? Gaffa tape?

I just tried the green stuff on the boiler today. Got a solid rolling boil going with the lid half on.


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## Hermies (28/10/17)

yeah gaffa tape will do .

Nice that insulation works a treat . I use it on my mash tun which is a 50lt keg hardly lose any temp it's even better with the HERMS .


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## RobinW (28/10/17)

I couldn't get a real boil going. 
Added that flooring as a test and it's away. 
Water in the sight tube bounces up and down and you hear it boiling.
Getting there.

I know a place that sells 2" thick sheets of Polystyrene but only in 2.4x1.2 meter slabs.
I'll look around.
Cheers


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## barls (28/10/17)

try your green grocer and ask for broccoli boxes


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## droid (28/10/17)

Could you buy a coil and recirculate through the urn?


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## RobinW (28/10/17)

I got a coil that need some love and that's an option but small steps.


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## Judanero (28/10/17)

I hear floating a sheet of al foil on the surface of the wort/mash also helps reduce heat loss


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## Hermies (28/10/17)

RobinW said:


> I got a coil that need some love and that's an option but small steps.


Well actually it wouldn't take much to stick it in the urn and pump the wort through it all you need is some hose connections from mash tun through the pump into the coil and back into the mash tun and you have yourself a HERMS system which will give you better control over the mashing proceedure .You could also cut out one of the tiers as you do have a pump. My suggestion would be to raise the mash tun a little higher so that you can gravity feed into the boil kettle and then you could bring down your urn (herms) and place it to one side of the boil kettle or mash tun and that way it would make it easier to carry pour and transfer liquids more safely and less strain on your back as well as having a more relaxed brew day . You have a great little set up going it just needs a little tweaking and it would make life a lot easier .


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## RobinW (29/10/17)

It's not a matter of just sticking it in the Urn. 
What you can't see is that the coil is so big it sits on the element and weighs close to 8 Kgs. 
Also water in the Urn can vary in temp by around 4 degrees so it would need a stirrer.
That's a completely separate project which I'll get around to eventually.
After I sort the cooler, I need to get the plate chiller setup and working.
As for water, I'm pumping it from the keg to the Urn and that's working well for me.


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## warra48 (29/10/17)

You do need to insulate your mash from the head space in your mash tun. It's where you are losing your temperature. I personally use 2 layers of yoga mat cut to fit, and I don't lose more than ½ºC over an hour or more. The other suggestions of polystyrene etc wil also work.


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## pcqypcqy (29/10/17)

I take it people are talking about something inside the Eski to reduce he headspace, but another option is to just add another layer around the outside. The cheapo yoga mats would probably go alright. Once you've arrested your temperature drop, you can then dial in the preheat accordingly.


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## pcqypcqy (29/10/17)

RobinW said:


> It's not a matter of just sticking it in the Urn.
> What you can't see is that the coil is so big it sits on the element and weighs close to 8 Kgs.
> Also water in the Urn can vary in temp by around 4 degrees so it would need a stirrer.
> That's a completely separate project which I'll get around to eventually.
> ...



Also, if you wanted a HERMS set up, could you not use the plate chiller but with hot water from your urn?


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## RobinW (29/10/17)

The whole outside of the esky is cool to the touch. I don't don't see any significant heat loss there. 
Bunnings has 1200x600x30 pressure extruded polystyrene insulation panels for $12. One of them will do this and another job for me.
I'd need a second pump to use a plate chiller.


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## pcqypcqy (29/10/17)

RobinW said:


> The whole outside of the esky is cool to the touch. I don't don't see any significant heat loss there.
> Bunnings has 1200x600x30 pressure extruded polystyrene insulation panels for $12. One of them will do this and another job for me.
> I'd need a second pump to use a plate chiller.




True enough with the pump.

That insulation should do the trick then, good luck with it.


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## Ducatiboy stu (29/10/17)

pcqypcqy said:


> *I take it people are talking about something inside the Eski to reduce he headspace*, but another option is to just add another layer around the outside. The cheapo yoga mats would probably go alright. Once you've arrested your temperature drop, you can then dial in the preheat accordingly.



Correct.

I just cut the lid of a broccoli box down to sit *on the mash in the esky*. This will help A LOT. As Warra stated, get less than 1º drop over 1-1/2 hrs

Just adding another layer of insulation wont have as much effect.


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## pcqypcqy (30/10/17)

Ducatiboy stu said:


> Correct.
> 
> I just cut the lid of a broccoli box down to sit *on the mash in the esky*. This will help A LOT. As Warra stated, get less than 1º drop over 1-1/2 hrs
> 
> Just adding another layer of insulation wont have as much effect.



True, but if you weren't keen on having something like that in your mash, you could insulate the outside of the whole thing and adjust your pre heat accordingly.

When I was using an eski for a mash tun, I was lucky and found a taller one with a smaller plan area, so I always had a more compact mash, even for smaller volumes, so headspace wasn't an issue. But if I was worried about it dropping (on a particularly cold/windy day for example), I'd just wrap it up in something and it usually helped.

Sounds like the OP has this sorted now.


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## Ducatiboy stu (30/10/17)

20-26ltr esky is perfect for 5kg mash


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## RobinW (30/10/17)

No joy here. Got the foam board yesterday arvo and cut a plug to go half way down. Still saw a 2+ degree drop over an hour.

Cut the plug so it sits on the water. Wrapped the ball valve with a towel. The manifold connects to it and it was hot and leaching heat.

It's still loosing between 0.2 and 0.4 every 10 minutes. I think the old coleman has seen better days.


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## TwoCrows (30/10/17)

Some eskies have more thermal mass. This means you would need to pre heat for a longer period of time or start at a higher temperature and allow the insulation to store/ remove water temp.

I haveand have used a 60ltr techni ice cooler and it sucks away all my heat as a mash tun. I scrapped it.


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## pcqypcqy (30/10/17)

RobinW said:


> No joy here. Got the foam board yesterday arvo and cut a plug to go half way down. Still saw a 2+ degree drop over an hour.
> 
> Cut the plug so it sits on the water. Wrapped the ball valve with a towel. The manifold connects to it and it was hot and leaching heat.
> 
> It's still loosing between 0.2 and 0.4 every 10 minutes. I think the old coleman has seen better days.




If you're losing heat over the whole mash, I'd say the overall insulative effect is not enough. Maybe try wrapping the outside as well and see if this arrests the fall. I know you've said it's cool to touch, but if you work out the heat loss in joules over the surface area of the eski, I doubt the surface temperature of the plastic would raise appreciably even with the heatloss you're describing. But, if you insulate the outside as well, you will lock it all in (or at least slow it down), so with the right pre heat you should be able to maintain a much more consistent temperature.

There are calculators around to work out the strike temperature to give you a target mash temperature, so you can dial in your start temp quite precisely. I used the built in stuff with beersmith and found it was pretty good.

What's your target mash temperature?


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## RobinW (30/10/17)

I'll move straight into plan B. Got that coil zip tied up and suspended in the urn. I'll try that but it'll need more work I'm sure.

I have beersmith.


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## Hermies (30/10/17)

RobinW said:


> I'll move straight into plan B. Got that coil zip tied up and suspended in the urn. I'll try that but it'll need more work I'm sure.
> 
> I have beersmith.


Good job now you are almost there with your mash tun problem .


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## RobinW (30/10/17)

Seems promising but there are issues to overcome.
I'll need to almost fill the Urn to cover the coil. Have to make more RO water.
Drop over 10L into the cooler and some of the coils are exposed but not critical. There are lots of coils.
You have to combine Urn temp and pump flow to get correct mash temp. Will need some experience with that one.
Leading on from that, there's a need for me to keep the Urn under sparge temp.
Certainly maintains a stable mash temp once you get it where you want it.
I'll need a couple more quick connects, a better way than coat hangers to suspend the coil and the stinking ball valve on the pump is leaking at the handle.
I'm pretty sure I'll get it sorted. Cheers all.


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## malt junkie (30/10/17)

RobinW said:


> Seems promising but there are issues to overcome.
> I'll need to almost fill the Urn to cover the coil. Have to make more RO water.
> Drop over 10L into the cooler and some of the coils are exposed but not critical. There are lots of coils.
> You have to combine Urn temp and pump flow to get correct mash temp. Will need some experience with that one.
> ...


Love your persistence, it took me years to build up my first 3v. Stupidly I sold it and moved on to 1V which I built; nothing wrong with 1v but I miss some bits and You can more easily stretch volume and gravity, and do other tricky shit that with 1v would just be a pain in the aRse. Sadly short of a stand, a couple of pumps and a couple of burners I have everything needed to go to 3v @60L herms, for some reason I want to be able to go 1hl 1060 so 1 big kettle short. Stay the course, work , kids, wife, life need to continue to fund the brewery expansion


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## RobinW (30/10/17)

It was always the plan to use the coil as a herms but not at this stage of the game.
It was 350mm diameter when I got it. God knows what the guy was using it in.
I rewound it around a corny keg and was going to shorten and solder it to suit the Urn.
It certainly needs a good clean probably inside and out.
Chucking it in now is just another pause in my plans I guess.
Oh well ...


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## Hermies (30/10/17)

RobinW said:


> Seems promising but there are issues to overcome.
> I'll need to almost fill the Urn to cover the coil. Have to make more RO water.
> Drop over 10L into the cooler and some of the coils are exposed but not critical. There are lots of coils.
> You have to combine Urn temp and pump flow to get correct mash temp. Will need some experience with that one.
> ...


Cut a coil or two to fit in the urn properly . I purchased a 7lt Big W pot for $11 and stuck 3mt of copper in it and get a ramp time of 1*C per min of course I had to buy a PID and have had it running for near on 10yrs . No complaints here .So if you do it now then the job is done and you kill two birds with one stone .


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## RobinW (30/10/17)

It's a 2400watt 48L Urn. All the 240V cables get melting hot when it's on. I can't run anything else when the Urn is on. I have to use an extension cord right now so bought a 15 Amp job and dremeled down the earth pin so it would fit in a 10A socket. My nephew the electrician recons the thermostat is slow, it overshoots a lot, so I had to get a PID to get the right temp, another delay. The thermowell for the pid is still coming. I was planing to replace the urn, the thing is just a hassle. I estimate that coil at 15 meters just in loops. But I'll work it out.


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## Hermies (30/10/17)

RobinW said:


> It's a 2400watt 48L Urn. All the 240V cables get melting hot when it's on. I can't run anything else when the Urn is on. I have to use an extension cord right now so bought a 15 Amp job and dremeled down the earth pin so it would fit in a 10A socket. My nephew the electrician recons the thermostat is slow, it overshoots a lot, so I had to get a PID to get the right temp, another delay. The thermowell for the pid is still coming. I was planing to replace the urn, the thing is just a hassle. I estimate that coil at 15 meters just in loops. But I'll work it out.


Are you able to get into the bottom of the urn where the thermostat is and wipe off the thermal grease .For this is the most likely point of all where it is slow


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## RobinW (30/10/17)

Yeah, been there done that, it did nothing. I've been working with electronics and electrical stuff all my life. I prefer the controller to be honest.
Was only $25 off fleabay, it's digital and I got 2 other thermometers here that agree with the sensor. The thermowell will clean up that wiring.
My nephew is going to replace the AC cable with one with thicker wires so it won't get so hot. Beats me paying for it 
I was hoping the next batch in the fermenter would be one of mine. But it don't look like it.

https://www.ebay.com.au/itm/Temperature-Controller-16A-Heating-Cooling-Home-Brew-Aussie-Plug-240V-16-A/272871990757?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649


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## Hermies (31/10/17)

If you spend the time now tinkering just think how easier it is going to be down the track to control the temps and do step mashes in fact just brew a great beer .


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## Matplat (31/10/17)

I don't run HERMS so I'm not an expert, but everything I've read about it suggests that having a large herms vessel (i.e. 40l urn) is not good for stable mash temps as you always end up overshooting your set point due to the large thermal mass controlling the coil temp.
If you're going to the effort of building a herms rig, would it be better to use a cheap big w 11l pot for the herms vessel? Or does a PID controller mitigate this issue?


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## malt junkie (31/10/17)

Matplat said:


> I don't run HERMS so I'm not an expert, but everything I've read about it suggests that having a large herms vessel (i.e. 40l urn) is not good for stable mash temps as you always end up overshooting your set point due to the large thermal mass controlling the coil temp.
> If you're going to the effort of building a herms rig, would it be better to use a cheap big w 11l pot for the herms vessel? Or does a PID controller mitigate this issue?


What's been said above is true, and a PID will to some extent try to prevent the over shoot, but in essence your trying to fry an egg with an industrial bast furnace, even if you shut down the furnace before put in your egg.... well it's charcoal. Stored energy is good, doling it out finitely is the challenge.


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## RobinW (1/11/17)

I don't think the size of the pot matters. There's a 50 gallon herms pot on utube. Controlling the heat looks like the key. Quite a few I looked at used the return mash temp to control the element and some halved the supply volts to the element while doing this so that would also limit overshoot.

I hung the coil in the Urn with a pair of SS turnbuckles I had here. Opened one hook on each a little so it could cup the tubing and hung the other end on the Urn rim then unwound them to get it as low as I could without sitting on the element or other bits. Had to clean off the sight tube and re-calibrate, the coil takes up about 5 litres of space. This was a 48L Urn.






Yesterday, I painted the MDF shelves on the stand before they turned into pulp. I was spilling water everywhere. Today I put 40L in the Urn, dropped 12L @ 75C into the cooler and after that only the very top of the coil was exposed. I added about 5L to cover the coil and set the Urn temp to 71C. I then started to recirculate from the cooler ball valve, through the coil and back to the cooler through the sparge frame. The cooler tap was wide open but the new pump valve was just open. I found a 1.7C difference between Urn temp and cooler temp so setting the Urn to 70.7C and the pid to turn on at 70.3C gave me 69C at the cooler. Cooler temp drifted back and forth between 68.9 and 69.2 over a 1 hour period while the Urn often overshot up to 72.5C without any effect on the cooler temp. In fact when playing with Urn temp it took ages for Urn temp changes to show up in the cooler temp. I'm pretty sure I can use this. 






The original cooler lid won't fit with the sparge frame in there so I used a piece of that foamboard to keep the steam in. I painted it with epoxy paint to hold it together. Tomorrow the Urn comes down to a lower shelf and the cooler goes up. Not the prettiest solution but it looks fixed to me.


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## Ducatiboy stu (1/11/17)

There are way more important things in life than loosing a few degrees with your mash

Honestly, at the end of the day it makes **** all difference, especially when you consider that most of the conversion is done in the first 30-40mins

No need to get all hung up about it


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## RobinW (1/11/17)

I think your missing the point. I have a cooler that looses almost 5 degrees an hour even after an hour of pre-heating.
I've fixed it in a big way and the only outlay was a new ball valve for the leaky one on the pump.
All the other bits where on hand.


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## Matplat (2/11/17)

Nice work Robin, looks like you're winning!


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## Ducatiboy stu (2/11/17)

RobinW said:


> *I think your missing the point*. I have a cooler that looses almost 5 degrees an hour even after an hour of pre-heating.
> I've fixed it in a big way and the only outlay was a new ball valve for the leaky one on the pump.
> All the other bits where on hand.



Nope


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## Dave70 (3/11/17)

Ducatiboy stu said:


> There are way more important things in life than loosing a few degrees with your mash
> 
> Honestly, at the end of the day it makes **** all difference, especially when you consider that most of the conversion is done in the first 30-40mins
> 
> No need to get all hung up about it



Pretty much this. 
On the back of some article I read, somewhere, likely here, I decided a full volume mash, no sparge, 2V system best suited my needs best. 
I enjoy my brew days and dont need some leaky hoses or some malfunctioning March pump interfering with my enjoyment. Which is to say, my drinking.


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## RobinW (4/11/17)

My plan is to eventually do concentrated double batches. I have a pile of 15L cubes here.
I should have the boil space to do a 30L batch. 15L in the fermenter, then add 5L of water to temp plus yeast.
Then the other 15L in a cube for ron. Only got room in the fridge for one bucket.

Still need a couple more test runs including a clean up run to make sure I got all the connectors right.
That plate chiller is amazing. Pumped boiling water through it the other day, it came out cold to the touch.
Good ole Gumtree...


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## RobinW (30/11/17)

Pumped 4 brews though so far and temp stability is no longer an issue.
Beer smith tells me 79% mash efficiency on the last brew but I still had volume issues.
I forgot to count losses in the chiller, almost 2 litres in that thing and it's so small.
Thanks to all for the help and prompting, I'm cooking now


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