Mash Tun issues

[RobinW]

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.

 

[Hermies]

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 .

 

[RobinW]

.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.

 

[Hermies]

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 .

 

[RobinW]

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

 

[barls]

try your green grocer and ask for broccoli boxes

 

[droid]

Could you buy a coil and recirculate through the urn?

 

[RobinW]

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

 

[Judanero]

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

 

[Hermies]

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 .

 

[RobinW]

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.

 

[warra48]

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.

 

[pcqypcqy]

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.

 

[pcqypcqy]

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.

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

 

[RobinW]

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.

 

[pcqypcqy]

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.

 

[Ducatiboy stu]

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.

 

[pcqypcqy]

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.

 

[Ducatiboy stu]

20-26ltr esky is perfect for 5kg mash

 

[RobinW]

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.