Diameter of mash tun

[pigsaarz]

Does the area covered by your mash make a difference, for example it seems logical to have a larger diameter mash tun so the grain bed isn't so deep to get a more efficient mash. Is this the case?

 

[Shaneoco1981]

I don't know. I assume it doesn't really matter, but I could be wrong. I would like to know. I have one of the igloo coolers that is used by most people.

 

[Dan]

This text is from chapter 17 John Palmer's How to Brew. Chapter 17 -

"Getting the Wort Out (Lautering)
17.2 Getting the Most From the Grainbed
The grainbed can be a few inches to a couple feet deep, but the optimum depth depends on the overall tun geometry as well as the total amount of grain being mashed. A good rule of thumb is: "The depth of the grainbed should be no less than one half the shortest dimension of the floor area, nor greater than twice the longest." In other words, the grainbed aspect ratio can vary between 1:2 and 2:1. If the grainbed gets too shallow, i.e., from lautering too little grain in too large a tun, then an adequate filter bed won't form, the wort will not clear, and you will probably get hazy beer. A minimum useful depth is probably about 4 inches but a depth of between 8-18 inches is preferable. In general, deeper is better, but if it is too deep, then the grainbed is more easily compacted and may not let any wort through, making lautering nearly impossible"

 

[frazier]

I've heard that it is easier to stir the mash if it is more wide, less deep. I have a rectangular cooler, haven't tried it with a circular type.

 

[Dan]

I have a 10 gallon circular cooler but started out with a rectangular one. I don't recall much difference between stirring in either though.

 

[pigsaarz]

Thanks for the input, I have a 60L and a 40L pot I have a false bottom in the 60 litre pot which holds 8L up to the level of the false bottom, I have been brewing batches of 23L ( the first three I made a right pigs ear of, but still drank them ) and this last brew I did was a Donnington SBA bitter which seems to have worked out really well, and I put it down to the grain bed being 3 to 4 inches deep.I wish I could go back in time and see how "Sven the Slayer of Christians" work out how to lay down his batches in 900AD I bet the brew houses then didn't have false bottoms,algebra,temperature controllers and sanitary conditions, then again we dont know what their beer tasted like either

 

[Dan]

I wonder what that beer tasted like too?