33L boiler build, what size and shape mash run?

[FarmerFred]

Hi I've completed a 33l boiler similar to Chard's instructable. I had been thinking of grabbing a 40l coolbox from Argos (£29.99) for the mash tun and either putting a false bottom in with some SS mesh I have lying around or copper pipe. But then I thought about getting another 33l bucket, insulating it and adding a false bottom or piping it. Thus would maybe work put cheaper as I can scrounge the insulation.
Does anyone have an opinion on mash tun size in comparison to boiler and also design? I thought a round bucket would make sparging easier. Many thanks for any help on this my first build.

[lord groan]

The mash tun doesn't necessarily need to be as big as the boiler. For a 33l boil you're likely to be mashing with about 10-12l of water +the grain of course, then sparging with another 20l roughly. So you can get away with a 20l or bigger mash tun.
My first MT is a converted mango chutney barrel which I enclosed in polystyrene, its about 35l capacity but I've never gone over 1/2 - 2/3rds full, and my brews are 5gall/40pt/23l jobs. I'm thinking its a bit too big so---
I've just got a 28l campingaz insulated coolbox at a bootsale and am trying to convert this to an MT, coz the foam is inside the walls it'll be much easier to clean than the polystyrene i've got now.

I've had a quick look at the Argos one you mention and i'm not sure but I don't think it is an insulated one. That'll make maintaining a steady temperature much harder. Some coolboxes have insuation between the inner and outer walls, its one of these you need really. Also if there is a lot of airspace above the grain you'll lose heat faster, so it's worth trying to match the mash tun to the brew size you're considering.
Good coolboxes will boast about the insulation - Igloo coolboxes use a "maxcold" description, coleman use "Xtreme" etc. These say they'll keep ice frozen for up to 5 days, but they are much pricier

If you can get one of these it'll work far better. Try having a look at coolboxes in a supermarket or camping store, give the sides a squeeze and feel the weight, insulated ones will have pretty solid sides and weigh more, the others will be hollow.
hope this helps a bit

[FarmerFred]

Thanks that's great advice. I have a solid 25l fv which I could wrap up in insulation as per Chard's instructable but add a false bottom with either a dinner plate or some mesh I have. I'll sleep on it and ponder coolbox or fv!
I've a chutney barrel which would lend itself nicely to a hlt. I saw pics of them being used as boilers so I assume they are OK up to 80c.
Really appreciate the help. Just had the boiler up to a rolling boil and no leaks

[woblylegs]

my boiler is 33 ltr. i used an igloo drinks cooler as mash tun last week for the first time. it worked a treat and kept temp. very well. 12-13 litres of water and the grain fit just grand. very easy to convert too. i bought it last year of ebay for £27.

[Rick_UK]

I used a 24l cheap coolbox with upgraded insultion (camping mats) for a couple of years and it was fine for mashing upto about 6.5kg of grain for a 23l brew. I would try the bucket if you can get decent insulation for free - it will work out cheper and likely do the job just as well and the extra capacity is useful and can mean you can batch sparge in 1 rather than 2 stages. I have since upgraded to a 35l thermo pot and prefer the round shape and extra capacity for this reason.

I would recommed a simple steel braid manifold - in my experience it never fails and works well for fly and batch sparging. False bottoms are not ideal for bach sparging and a PITA to DIY or expensive to buy.

Rick

[FarmerFred]

I do like the look of those round igloos but thinking now I'll take a look at converting the fv. I've got some copper pipe to use up and so may use that up instead of the steel braid, although that would be a lot less work! I'd thought about the false bottom as got some smallish holed mesh kicking about.

[Rick_UK]

Have a go at a false bottom if you fancy one (fnaar, fnaar!) will prob be fine for fly sparging. Maybe someone will chime in who has a design that works well for batch sparging too?

Another bomb proof option I would recommend would be a grain bag - low tech and un-sexy but perfectly functional and no need to ever worry about a stuck mash and all you need to do is fit a tap to your MT. I cobbled one up from a net curtain when my copper manifold got blocked and it saved the day! (SWMBO wasn't overly impressed mind!)

[FarmerFred]

It keeps getting easier and easier this build! I do have a grain bag on hand, might just chuck that in the fv which already has a tap in place. Would those plastic taps stick the heat? Must do I'm sure. I hope you hid up the Missus' rolling pin
*only just noticed my predictive text error in title!

[FarmerFred]

One other question- does anyone insulate their boilers?

[awalker]

my boiler is 33 ltr. i used an igloo drinks cooler as mash tun last week for the first time. it worked a treat and kept temp. very well. 12-13 litres of water and the grain fit just grand. very easy to convert too. i bought it last year of ebay for £27.

Good to here I just bought one as well.

my boiler is 33 ltr. i used an igloo drinks cooler as mash tun last week for the first time. it worked a treat and kept temp. very well. 12-13 litres of water and the grain fit just grand. very easy to convert too. i bought it last year of ebay for £27.

[FarmerFred]

Today I decided to keep the FV for fermentation and instead buy a cheap £9 24l coolbox from Tesco. Needless to say it was very flimsy and light feeling.


I took it apart to find 5 sheets of thin polystyrene. hmm.


So I wrapped the sheets up in tinfoil and taped it well along the top edges especially to stop the inner splitting it. I then added some leftover loft insulation (never throw anything away) underneath and around the sides.


The lid had no insulation whatsoever and so i used a thick piece of insulation and taped it with a thick plastic bag. Will probably improve on this later.
I filled up 12l of water and took a temperature of 73C.


Then I just put a binbag underneath which helped to seal up the lid and stop condensation forming on the taped edges of lid. I also put a puffa jacket on after 20 mins as I could feel some warmth, especially the corners, not hot but warm.

After 1 hour I removed the lid and got a temperature reading of 71C so a 2C drop. I'm pretty chuffed with that as half thought it would be 10C less. All in took about an hour to mod it and cost nothing on top of the £9. Out of interest I brimmed it and the coolbox helpd about 20l, not the 24 as advertised. Should be plenty for my 33l boiler. Next step is to add the tap and pipework. The insulation has definitely beefed up the coolbox and added to the weight but the plastic is thin to say the least!

Thanks for the advice on here. Getting excited as first AG brew day moves that step closer.

[Fil]

Nice work sorting out the tun insulation. and if u just filled with 12l and measured the temp and closed without any preheating of the tun i think a lot of the 2C temp drop you appreciated may have been warming up the lid and tun top so i think you may get better performance with a prewarmed tun.

[YeastWhisperer]

I continuous sparge with a round tun and a proper false bottom, but that's how I learned to brew. I have reached the point where I could not duplicate my results with batch sparging. However, I always recommend batch sparging to new brewers. It's a much more foolproof process that does not require one to master much in the way of technique in order to be able to achieve acceptable results (continuous sparging can be unforgiving). Plus, any container that will hold temperature can be converted into a mash/lauter tun for use in a batch sparging-based brew house. With continuous sparging, lauter tun geometry, grain bed depth, and false bottom design matter because one wants to avoid channeling through the bed.

By the way, are large volume beverage coolers available in the UK? They are primarily used at construction sites and sporting events here in the United States.

[FarmerFred]

Think you could be right Fil. Thinki can live with 2c drop while I'm just experimenting and finding my AG feet.
I thought batch sparging would perhaps be more forgiving Yeastwhisperer. Perhaps in the future it would be something to aspire to but right now I'm focusing on basics.
I'm not sure if we have such a glut of coolers and I think 50-60l is as big as they get here. Building sites would probably worry more about the kettle here in blighty than a cooler!!

[Rick_UK]

Same as my first MT except I filled the lid cavity with expanding foam and resealed it. It will hold its temp much better with the increased density of the grain. I think I lost at least 2 degrees when I tested mine with water but lost nothing with a proper mash with 5kg grain.

Just a tap to fit and yr away pal - I just drilled a hole for a tank connector and added a ball valve. It's a good idea to put some packing around the hole between the skins to improve the seal. Brew on