New mash tun advice

[laithclark]

I currently have a 5 gallon circular igloo mash tun which is great, but I recently did a 23 litre 5.5% brew and it was struggling with the grain and water volume required and was a bit of a pain. However it's great for a 18/19 litre brew of around 4.5%.

What I want is one that will cover to do small experimental brews of 10 litres but also allow me to do bigger brews such as the one that caused me the issues. I am considering the 48 litre square igloo coolbox option as sold by most home brew shops as a deluxe mash tun.

Before I take the plunge will it cope with both brew sizes well?

thanks in advance

[Mr. Dripping]

Buy the best (and within reason the biggest) you can afford would be my advice.
Bigger tun will do smaller batches no problem, you could even do full volume mashes....if you find you are losing too much heat during mashing, you can use a piece of Kingspan placed over the mash to lessen the air pocket.

If you have the funds I would recommend a thermopot mash tun with a false bottom (mr lard or homebrewbuilder).....will last many, many years

[irv]

they are pretty simple and inexpensive to make. you could buy a cool box and re-use the parts from the igloo mash tun.
or keep the smaller one for smaller brew lengths?

[laithclark]

Thanks for the comments, I should have added much as I would like to keep the current coolbox funds and space don't really allow it at the moment. I think the bigger igloo it is then....or a thermopot!

[JonoT]

I have the 48L igloo coolbox converted into my mashtun there is plenty of great guides on how to convert. Its lasted well for me and holds temp fine on a 30L brew.

[Sadfield]

Hi, I also have the 19L round Igloo mash tun. Can't really see why, what you want to do, isn't easily achievable.

For example, throwing some figures into beersmith.

At 70% efficiency. A single infusion (medium body) mash with 6kg of grain would give 23L of wort at an OG c1.057 fermenting out to about ABV 5.6%.

Mashing at 2l/Kg in an 19L Igloo would only require a mash volume of 17.21L (mashing in with 13.3L).

What were the issues you encountered?

If you were to predominately brew 10L batches I would stick with your current set up. I may be out on my own here, but, feel that going bigger would compromise your small batch size, in terms of heat lose and dealing with the larger head space. Surely a full mash tun is better than one half full?

Also, controlling the consistency and quality of lautering, particularly sparging, may be an issue if the grain bed is too shallow and spread out over a larger area. Just a thought.

[laithclark]

I use the batch sparge method rather than fly sparging so that means the volumes in the tun are much bigger at one time rather than it just passing though the grain bed. Perhaps I ought to switch to fly sparging in preference my issue then will be having the height for the gravity to drive the sparge arm and collect the wort.

[Mr. Dripping]

You can sparge in 3 or 4 batches, this will help you with bigger beers.

[Sadfield]

I don't use a sparge arm, as when doing small batches the flow rate needed to drive one would result in sparging too quickly. I used pierced tin foil on top of the grain bed and trickle the water in. I get between 77-80% efficiency with this minimal set up.