DIY Mash Tun

[Triker750]

Hi Folks, Little advice please.
Everywhere i look i see cool boxs used as mash tuns, question i have is do i need to use one.
I have an idea to find a large plastic box, i can get one from work, and insulate it with some fairly thick polystrene insulation, so in effect i am making a diy cool box.
Is there any reason people dont do this, is it just the cool box route is easier.?????

Just finished my Keg boiler project and its a good un, so i want to start the mash tun now, but i want to do it all for free with stuff i can get at work.

Thanks,
Bob :

 

[Moley]

Coolboxes are readily available, fairly cheap and already have just-about-adequate insulation.

In short, they are an easy option.

As long as it's food grade and you can lag it well, use anything you like.

 

[Triker750]

Cheers Moley,
I thought that would be the case from my reading on the subject.
Food grade is no problem as i work in the food trade, insulation is no problem as we have tons of it left over from a refrigeration project.
So, thats tomorrows work load sorted out. (dont let the boss catch you)
Thanks again.
Bob :

 

[Kev888]

A lot of the cheapo cool boxes work but have fairly poor insulation (1/2" styrene in the sides, none in the lid etc) and may need it supplimenting in some cases, so there's a good chance you could do a better job with a purpose-made DIY one.

So +1 to what moley said and also pay attention to the lid seal, as letting the vapour out will help it to cool.

Cheers
kev

 

[Triker750]

Nice one Kev,
Had given so much thought to the insulation on the "Box" and the drainage system i had overlooked the sealing of the lid to the body.
Got it in hand now, a few Home brews and a think will sort it.

Also if anyone sees this tonight, Will a 5.5 gallon mash tun let me do 5 gallon Brews, batch sparging./??

Bob :

 

[Kev888]

It depend on the grain bill (a bigger one means both more space needed and more liquid retained in the wet grain), and other losses to dead space in the MT and boiler, losses to hops and losses to evaporation and that kind of thing.

I'd estimate that with 'typical' sort of losses a 5.5gallon MT would just about give you a 5gallon brew of average gravity, but if you may be wanting to make some stronger brews and/or with lots of hops and/or longer boil times then you'd probably have to reduce the brew length, do more than two batch sparges or fly sparge.

Personally i'd aim for a bit more - its more flexible and also more headroom makes doughing in less messy too!

cheers
kev

 

[WelshPaul]

Sorry for a real noob question, but what exactly is a mash tun and what is it used for? How does it differ from allowing the mash to cool in a FV?

 

[richc]

Sorry for a real noob question, but what exactly is a mash tun and what is it used for? How does it differ from allowing the mash to cool in a FV?

Very simply, for all grain brewing, you need to mix the grain with water at a certain temperature and hold it at this temperature for a period of time. This is to allow enzymes in the malt to convert the starch into simple sugars that the yeast can then turn into alcohol. This process is called mashing and is done in a mash tun.

 

[WelshPaul]

OK, thanks. I was under the impression that this is done in a boiler: are they one and the same?

 

[StubbsPKS]

OK, thanks. I was under the impression that this is done in a boiler: are they one and the same?

The liquid that comes out of the mashtun (MT) is called wort. This wort is what goes into the boiler and what is eventually turned into beer :)

 

[Kev888]

Part of the confusion may be because some people use their boiler as a mash tun, especially with (for example) Brew In A Bag. This is where the ingredients are lowered in and taken out of the brewing liquid in a net bag, removing the need to transfer the liquid in and out of a separate (mash) tun holding the grains.

But the aim is the same in that the temperature of the 'mash' must be maintained during the time that the grains are steeped in the liquid

Cheers
Kev

 

[WelshPaul]

Yep, that clears it up, thanks. I'll be getting a combined boiler/mashtub after my holiday as storage won't allow for two seperate ones.

 

[Mr.Everready]

Yep, that clears it up, thanks. I'll be getting a combined boiler/mashtub after my holiday as storage won't allow for two seperate ones.

what kind of brewing do you intend to be doing ?

 

[WelshPaul]

Not really sure yet: there's a world of possibility out there! I'm a fan of pale ales and my housemate likes stouts and strong ales, so it will be anything really. We're going the AG route anyway rather than using extract - a 15l batch is already happily fermenting as we speak! :)

 

[Cussword]

Yep, that clears it up, thanks. I'll be getting a combined boiler/mashtub after my holiday as storage won't allow for two seperate ones.

Ooooh, if Moley sees this. :lol:

 

[StubbsPKS]

Yep, that clears it up, thanks. I'll be getting a combined boiler/mashtub after my holiday as storage won't allow for two seperate ones.

Will you be doing BIAB then? Seems there are quite a few more baggers on this forum than I previously thought.

 

[WelshPaul]

Most likely as I HATE cleaning up!

 

[StubbsPKS]

Most likely as I HATE cleaning up!

Cleaning isn't much better with a bag, LOL.

You still get hops floating around (unless you use a hop sock). The problem with using hop socks is that the hops act as a really good filter for catching break material and keeping it out of your FV :-D