How to build a cool box mash tun

[HisDudeness]

Lost a couple of degrees over an hour with 12l of water in it, I am hoping it will be no more than a degree of loss with a full size mash. If it is more I will be cannibalising some camping gear! :lol:

 

[baggybill]

Nice work :thumb:and great post too:hat:

I might end up going down this route after spending hours faffing about with a bag today again... I seem to lose a helluva lot of time between mash end and boil, faffing about trying to sparge in various ways

 

[HisDudeness]

Nice work :thumb:and great post too:hat:

I might end up going down this route after spending hours faffing about with a bag today again... I seem to lose a helluva lot of time between mash end and boil, faffing about trying to sparge in various ways

That was exactly what persuaded me to do this, trying to haul the mash bag out of my boiler was resulting in lots of spilt wort and scalded hands. Leaving the grain in the tun should keep things a lot cleaner and easier!

 

[HisDudeness]

Any particular reason this was moved from the 'how to section'? Is that not the most appropriate place for this post or am I missing something!

 

[keat64]

Did you cut slits on both sides of the manifold.
Maybe if you fitted it with slits down, there would be less dead space ?

 

[HisDudeness]

Did you cut slits on both sides of the manifold.
Maybe if you fitted it with slits down, there would be less dead space ?

No, they are on one side only and they are already face down (it looks the other way in some of the photos but thats the marks from the rollers on the pipe cutter). I think the manifold sits a bit higher than it could because the plastic base sort of springs up in the middle and stops it sitting flat. Im hoping once it has had a couple of mashes in it the plastic will be sort of ironed flat by the heat and weight. Either way it doesnt really matter too much just need to account for the extra litre with more sparge water.

 

[HisDudeness]

Tried it out today with a 19L batch results were as follows:

Grain 4.05kg
Target 66c Mash with 11L
Strike water 74.5c
Actual Mash Temp 66.2
Ambient room temp was 21c

After 1 hour the centre of the mash was still at 66c after stirring to equalize the temparature the temp was 65.3c

Just under a degree loss over 1 hour :mrgreen:

I sparged with two 9L batches at 73c, temp was a bit lower than intended as I lost more heat than expected when pouring water from boiler into the tun. Think I need this at around 85 next time.

After boil and cooling the OG was on target and hit the expected 72% efficiency. Success! :thumb:

 

[HisDudeness]

One small addition to the tun was some insulating foam around the stem of the tap, I noticed this was pretty hot during the mash so thought this might help a bit.

 

[HisDudeness]

The cooler was only about half full with this batch so it should be able to handle grain bills up to about 7-8kg total depending on mash thickness.

 

[HisDudeness]

Using a mash tun meant I could lauter the wort before draining which seemed to clean things up nicely and the resulting beer has much less trub in the fermentor (less than a cm, I would get an inch or more using a mash bag).

The batch sparge method I used was as follows:

Stir grain at end of mash time

Recirculate a few litres using a jug til wort is clear of debris and particles

Fully drain mash tun (I collected about 6.5L from first run off)

Add first batch sparge water to give 75-77c in tun (9L in this case) stir, leave 10-15mins

Stir again and recirculate then drain (Collected about 8.5L)

Add second batch sparge water (9L again) stir, leave 10-15mins

Stir again and recirculate then drain (Collected about 8.5L)

Check pre-boil volume and sparge a little more if required

I found this method very easy to follow and apart from a few issues hitting correct temps it all went well, it was far far easier and less messy than using a mash bag!

 

[keat64]

Some cracking tips there dudeness.
Can't wait to have a go.

 

[marinali29]

amazing post :thumb:

 

[garmel52]

Great Post.I have all bits and pieces to build my Mashtun the same as yours apart from the 1/2 BSP plastic tank connector.Can you post a link or let me know where you bought it please.ps GREAT PICS

 

[HisDudeness]

Great Post.I have all bits and pieces to build my Mashtun the same as yours apart from the 1/2 BSP plastic tank connector.Can you post a link or let me know where you bought it please.ps GREAT PICS

Here is the one I got:
http://www.ebay.co.uk/itm/201397480265?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT
The threaded pipe is quite long on this one so I cut it down with a hacksaw, also you may need to wrap some PTFE round the thread to keep the leaks out. I used the rubber washer on the inside of the tun.
Hope that helps :thumb:

 

[Tony1951]

Thanks Mr Dudness. This is an excellent post. This si the next beer related project for me and the guide makes it much easier and less likely that I waste time ruining something by guessing at what to do.

Cheers.

 

[garmel52]

Thanks for that ORDERED.Now I need to work on SWMBO For a brew kettle then it's the Dark Side!!!:thumb:

 

[Notlaw]

Crikey... how did I miss this when I was trawling the forum?!?!

Cracking guide. I think I'll format into a document to save me having to try and follow online instructions (bound to end up with a dropped/drilled tablet!)

Cheers!

 

[Tony1951]

Thanks for that ORDERED.Now I need to work on SWMBO For a brew kettle then it's the Dark Side!!!:thumb:

Dark side? Come into the light brother.

You can always use a15 litre pot on the stove while waiting to convince swimbo - just mind you don't slop wort about in the kitchen like I did or you might get a thick ear... :)

 

[garmel52]

Yeah thought about starting with a 15litre pot might give it a go:thumb:

 

[Dutto]

Daft question maybe but why have you got the slots on the top-side of the manifold?

If you had them on the under-side wouldn't that result in less deadspace?

PS 32ltr Thermos Coolbox due to arrive in two days time and all tubing, elbows etc ready to go!